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TDMS Study 05040-01 Pathology Tables

NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97
Route: GAVAGE                                                                                                     Time: 09:41:17




       Facility:  American Biogenics Corp.

       Chemical CAS #:  000123319

       Lock Date:  None

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All






































                                                              Page   1

NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Basophilic Focus                     | 2  2           2     2  2     2  3  1           3  2           2  3      |             
      Clear Cell Focus                     |                   2     2              2           2                     |             
      Congestion                           |                                                                          |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Cystic                 |                                                                          |             
      Eosinophilic Focus                   |                                                                          |             
      Fatty Change                         |       3                                1                 3               |             
      Hematopoietic Cell Proliferation     |             1                                         2                  |             
      Hepatodiaphragmatic Nodule           |             X                    X           X        X              X   |             
      Inflammation, Chronic                | 1  1           2  1  1  3     2  1  1        1  1  1  1     1  1  1  2   |             
      Inflammation, Granulomatous          |                         2                                                |             
      Mixed Cell Focus                     |                         2                             2                  |             
      Necrosis, Coagulative                |                                                       3                  |             
      Bile Duct, Hyperplasia               | 2  2  2  1  1  2  1     3     2  2  1        1     2  2     1  2     2   |             
      Centrilobular, Atrophy               |                                                                          |             
      Sinusoid, Dilatation                 |                                                                2         |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +                                                                  |             
      Arteriole, Inflammation, Chronic     |                                                                          |             
      Fat, Necrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Atrophy                              |       1                                      2                           |             
      Inflammation, Chronic                |                                              2                           |             
      Duct, Fibrosis                       |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Atrophy, Focal                       |                                                                          |             
      Cytoplasmic Alteration               |                                                                          |             
      Duct, Inflammation, Chronic          |    1              1                                1                     |             
      Duct, Metaplasia, Squamous           |    1  1                             2                                    |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Acanthosis                           |                         2                                                |             
      Hyperkeratosis                       |                         3                                                |             
      Hyperplasia, Papillary               |                         2                                                |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   2                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Ulcer                                |       3                                                  2               |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                        +                                 |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Cardiomyopathy                       | 1  2           2  2  2  1     2  1  2  2     3  1  2     1  1  3  1  1   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Angiectasis                          |                                     3           2                        |             
      Degeneration, Fatty, Focal           |                                                 2                        |             
      Degeneration, Focal                  |                1                                                         |             
      Hematopoietic Cell Proliferation     |             2                                         2                  |             
      Hyperplasia                          | 2              1                    1  1           1              2      |             
      Hypertrophy, Focal                   |                                                 1                        |             
      Hypertrophy                          |                                                                          |             
      Pigmentation, Hemosiderin            |                                     3                                    |             
      Vacuolization Cytoplasmic            |       3  2                                               3               |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |                      3           3           2           1     1  1      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  M  +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
      Hyperplasia                          |                                              1                           |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |                                                    2     2               |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Pars Distalis, Angiectasis           |                3                                                         |             
      Pars Distalis, Cyst                  | 1  3  2        1     3           3  3              2  2           3      |             
      Pars Distalis, Hemorrhage            |                                                                          |             
      Pars Distalis, Hyperplasia           | 2     3  2     3     3        4  2  2  3     3  4  3  2     2     3  2   |             
      Pars Intermedia, Cyst                |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Ultimobranchial Cyst                 | 2                                                                        |             
      C-Cell, Hyperplasia                  | 2        2  2  1     2  4     2                    2                     |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +     +  M  +  M  M  +  +  +  +  +  +  +  +  +   |             
      Abscess                              |       2                                                                  |             
      Cyst                                 |                   2                                                      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   3                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                | 2                    2  2     1              2                           |             
      Inflammation, Suppurative            |                                                 1           1            |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Atrophy                              |                                           2                              |             
      Follicle, Cyst                       |                                                                          |             
      Periovarian Tissue, Cyst             |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Cervix, Abscess                      | 3                                            3                           |             
      Cervix, Prolapse                     |                                                       3                  |             
      Endometrium, Hyperplasia, Cystic     |    2     2                    2     3        2           2  2     2      |             
                                            __________________________________________________________________________|             
   Vagina                                  | +                                                     +                  |             
      Dilatation                           |                                                       3                  |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +                                +                                 |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Myelofibrosis                        |                                                                          |             
      Erythroid Cell, Hyperplasia          |             3                                                            |             
      Myeloid Cell, Hyperplasia            |             3                                                            |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Pancreatic, Hematopoietic Cell       |                                                                          |             
          Proliferation                    |                                                       3                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia, Plasma Cell             |                                           4                              |             
      Sinus, Ectasia                       |                         2                                                |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Congestion                           |                                                                          |             
      Hyperplasia, Macrophage              |                                  3                                       |             
      Sinus, Ectasia                       |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hematopoietic Cell Proliferation     |             3                                         3                  |             
      Pigmentation, Hemosiderin            |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  M     +  +  +  +  M  +  +  +  +  +  +  +  +  +   |             
      Cyst                                 |                                     2                                    |             
      Arteriole, Mediastinum, Inflammation,|                                                                          |             
           Chronic                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Cyst                                 |                         4     4                       3        3  2      |             
      Hyperplasia                          | 2  2  4     2  2        3     2  3  3              2  3  4  2  3         |             
      Duct, Fibrosis                       |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   4                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Cyst Epithelial Inclusion            |                                                                          |             
      Ulcer                                |       3     2                                                            |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         |    2                 3                                                   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +     +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                        +                                 |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Compression                          |                   X     X                                      X         |             
      Meninges, Hemorrhage                 |                                                                          |             
      Pons, Hematocyst                     |                                                                          |             
      Ventricle, Dilatation                |                               3                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |       +  +  +                             +                              |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Interstitium, Inflammation, Chronic  |                   1                       2                              |             
      Pleura, Inflammation, Chronic        |                      1                                                   |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                |                      2                                                   |             
      Inflammation, Suppurative            |                                           3                              |             
      Lumen, Foreign Body                  |                                           2                              |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 1     1  1  1  2  1  2  2     1  3  1     2  1  2  3  2     2        2   |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                             2            |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 2  2  1  1  1  3  2  2  2     2  3  1  2  3  1  2  3  2  2  3  2  2  3   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                |    1           1                             2                           |             
      Glands, Cyst                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     | +                                                                        |             
      Retina, Atrophy                      | 3                                                                        |             
                                            __________________________________________________________________________|             
   Harderian Gland                         | +                                                                        |             
      Inflammation, Chronic                | 2                                                                        |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   5                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 5| 7| 7| 7| 7| 4| 7| 7| 7| 5| 3| 7| 7| 7| 6| 6| 7| 7| 7| 7| 4|             
                             DAY ON TEST   | 3| 2| 2| 0| 0| 3| 3| 3| 0| 5| 3| 3| 2| 7| 7| 3| 3| 3| 5| 4| 3| 3| 3| 2| 5|             
                                           | 1| 9| 2| 1| 0| 1| 0| 0| 2| 8| 1| 1| 9| 5| 2| 0| 0| 0| 8| 6| 1| 0| 0| 9| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                | 2                                   1        1  1  2           1     1   |             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 3  1  2  2  1  2  2  1  2     2  1  2  1     2  2  3  2        4  2  2   |             
      Pelvis, Dilatation                   |          2                                                               |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                                                                      1   |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                |    1                                         2                           |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   6                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Basophilic Focus                     | 2  2                 2        2  2  2        4     1        1  2  2  1   |             
      Clear Cell Focus                     |                                                                          |             
      Congestion                           |                                                                          |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Cystic                 |                                  1                                       |             
      Eosinophilic Focus                   |                                                                1         |             
      Fatty Change                         |          2     2                                      2                  |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hepatodiaphragmatic Nodule           |                                     X           X                    X   |             
      Inflammation, Chronic                | 1  1              1  1        2  1  1        2              1  1  1  1   |             
      Inflammation, Granulomatous          |                                                                          |             
      Mixed Cell Focus                     |    2                          3                                          |             
      Necrosis, Coagulative                |                1                                                         |             
      Bile Duct, Hyperplasia               |    1     2     2  1  2        2  2  1        2     2  2     1  2  2      |             
      Centrilobular, Atrophy               |                2                                      1                  |             
      Sinusoid, Dilatation                 |                               1                                1         |             
                                            __________________________________________________________________________|             
   Mesentery                               |                +                    +                 +                  |             
      Arteriole, Inflammation, Chronic     |                                                                          |             
      Fat, Necrosis                        |                                     2                                    |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Atrophy                              |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
      Duct, Fibrosis                       |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Atrophy, Focal                       | 1                                                                        |             
      Cytoplasmic Alteration               |                                                    1                     |             
      Duct, Inflammation, Chronic          | 2                    1                          1  1  1           1      |             
      Duct, Metaplasia, Squamous           |                      1                                               1   |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia, Papillary               |                                                                          |             
      Inflammation, Chronic                |                                                       1                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   7                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                                      +                  |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Cardiomyopathy                       | 3  2  1        2  1  2        2  2  1        1  1  2        2  2  1  1   |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Accessory Adrenal Cortical Nodule    |                                  X                                       |             
      Angiectasis                          |       4              4                                      3            |             
      Degeneration, Fatty, Focal           |       2        4                             2                       1   |             
      Degeneration, Focal                  |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hyperplasia                          | 2                                            2                    3      |             
      Hypertrophy, Focal                   |                                                                          |             
      Hypertrophy                          |                                                                      2   |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Vacuolization Cytoplasmic            |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hyperplasia                          |                1  1           1                       2        2         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hyperplasia                          |                                                 2                        |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Pars Distalis, Angiectasis           |                                                                          |             
      Pars Distalis, Cyst                  |                4                 2  2        2     2           1  2      |             
      Pars Distalis, Hemorrhage            |                                                                          |             
      Pars Distalis, Hyperplasia           |                                  2           1     3  3        2  2      |             
      Pars Intermedia, Cyst                |          2                                                               |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Ultimobranchial Cyst                 |                                                                          |             
      C-Cell, Hyperplasia                  | 2  3           4     1           2           2     2        2     1      |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Abscess                              |                                                                          |             
      Cyst                                 |                2                                   3                     |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   8                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Hyperplasia                          |       3                                                                  |             
      Inflammation, Chronic                |                                                       1                  |             
      Inflammation, Suppurative            |                                  1                                       |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Atrophy                              |                      3                                                   |             
      Follicle, Cyst                       |                   2                                               3      |             
      Periovarian Tissue, Cyst             |       3                                                                  |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Cervix, Abscess                      |                                                                          |             
      Cervix, Prolapse                     |                                                             4            |             
      Endometrium, Hyperplasia, Cystic     |                               2                 2                 3      |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
      Dilatation                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +                                   +  +                  |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Myelofibrosis                        |                                                       2                  |             
      Erythroid Cell, Hyperplasia          |                                                                          |             
      Myeloid Cell, Hyperplasia            |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Pancreatic, Hematopoietic Cell       |                                                                          |             
          Proliferation                    |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hyperplasia, Plasma Cell             |          3                                   3                 3         |             
      Sinus, Ectasia                       |                                              2                           |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +        +  +  +        M  +  +  +     +  +  +  +   |             
      Congestion                           |                                                                          |             
      Hyperplasia, Macrophage              |    2                                                                     |             
      Sinus, Ectasia                       |    2     3                                                               |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +     +  +  +        +  +  +        +  +  M  +     +  +  +  +   |             
      Cyst                                 | 2                             3                                          |             
      Arteriole, Mediastinum, Inflammation,|                                                                          |             
           Chronic                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Cyst                                 |       3                             3                       4  2  3      |             
      Hyperplasia                          | 3  2  3        2  2           2     3        2        2     1     1  1   |             
      Duct, Fibrosis                       |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page   9                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Cyst Epithelial Inclusion            |                               X                                          |             
      Ulcer                                |                                                                          |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Compression                          |       X                                                              X   |             
      Meninges, Hemorrhage                 |                                                                          |             
      Pons, Hematocyst                     |    3                                                                     |             
      Ventricle, Dilatation                |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +                                            +                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Hemorrhage                           |          2                                                               |             
      Hyperplasia, Macrophage              |          3                                                               |             
      Hyperplasia, Adenomatous             |                                              1                           |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                                                          |             
      Pleura, Inflammation, Chronic        |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Inflammation, Chronic                |                2                    2                          1         |             
      Inflammation, Suppurative            |                                                                          |             
      Lumen, Foreign Body                  |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         |    1  2  1     2  1  1        2              1  2  2        1     1  2   |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                          |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 1  2  2  2     3  1  2        2     3        1  2  2        1     2  3   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Inflammation, Chronic                |                                                                          |             
      Glands, Cyst                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                              +                           |             
      Retina, Atrophy                      |                                              4                           |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                              +                           |             
      Inflammation, Chronic                |                                              2                           |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  10                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 4| 7| 7| 7| 6| 4|             
                             DAY ON TEST   | 2| 2| 2| 5| 5| 3| 3| 2| 5| 5| 3| 3| 3| 5| 5| 3| 2| 2| 4| 5| 3| 3| 2| 7| 5|             
                                           | 9| 9| 9| 3| 8| 1| 0| 9| 8| 8| 1| 1| 1| 8| 8| 1| 9| 9| 7| 8| 1| 1| 9| 4| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|             
    VEHICLE                                | 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Inflammation, Chronic                | 1     1                                         1           1  1  2      |             
      Mineralization                       |    1                                                        1            |             
      Nephropathy                          | 4     2        2  2  3        2  3  1        3  3           3  2  3  1   |             
      Pelvis, Dilatation                   |                                                                          |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                                                 1                        |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +        +  +  +        +  +  +  +     +  +  +  +   |             
      Inflammation, Chronic                |                                                    1           1  1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  11                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |      A     |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  A  +  +  A  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Basophilic Focus                     | 3  1        3     2  2  3                                                |     30  2.1|
      Clear Cell Focus                     |                                        1                                 |      5  1.8|
      Congestion                           |                            4                                             |      1  4.0|
      Cytomegaly                           |                            3                                             |      1  3.0|
      Degeneration, Cystic                 |                                                                          |      1  1.0|
      Eosinophilic Focus                   |                                                                          |      1  1.0|
      Fatty Change                         |          2                 2           2                                 |      9  2.1|
      Hematopoietic Cell Proliferation     |                                                                          |      2  1.5|
      Hepatodiaphragmatic Nodule           |                   X                                                      |      9     |
      Inflammation, Chronic                | 2  1  1        1  1  1  1        1  1  2                                 |     39  1.2|
      Inflammation, Granulomatous          |                                                                          |      1  2.0|
      Mixed Cell Focus                     |                                                                          |      4  2.3|
      Necrosis, Coagulative                |          2                 3                                             |      4  2.3|
      Bile Duct, Hyperplasia               |    1  1        2  2  1     3  2  2  2  1                                 |     41  1.7|
      Centrilobular, Atrophy               |          2                 4                                             |      4  2.3|
      Sinusoid, Dilatation                 |                                                                          |      3  1.3|
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                          +           +                                 |   7        |
      Arteriole, Inflammation, Chronic     | 4                                                                        |      1  4.0|
      Fat, Necrosis                        |                            2           4                                 |      3  2.7|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Atrophy                              |                                                                          |      2  1.5|
      Inflammation, Chronic                |                                                                          |      1  2.0|
      Duct, Fibrosis                       | 3                                                                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Atrophy, Focal                       |                                                                          |      1  1.0|
      Cytoplasmic Alteration               |             1        2                                                   |      3  1.3|
      Duct, Inflammation, Chronic          | 1        1        1              1                                       |     13  1.1|
      Duct, Metaplasia, Squamous           |                                                                          |      5  1.2|
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  12                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |      A     |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Acanthosis                           |                                                                          |      1  2.0|
      Hyperkeratosis                       |                                                                          |      1  3.0|
      Hyperplasia, Papillary               |                                                                          |      1  2.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Ulcer                                |                            3                                             |      3  2.7|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   3        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Cardiomyopathy                       | 2  1  1  1  1  2  2     2  2  2  2     1                                 |     46  1.6|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Accessory Adrenal Cortical Nodule    |                                                                          |      1     |
      Angiectasis                          |                                                                          |      5  3.2|
      Degeneration, Fatty, Focal           |       2        1     1                                                   |      8  1.9|
      Degeneration, Focal                  |                                                                          |      1  1.0|
      Hematopoietic Cell Proliferation     |                                                                          |      2  2.0|
      Hyperplasia                          |                1                                                         |     10  1.6|
      Hypertrophy, Focal                   |                                                                          |      1  1.0|
      Hypertrophy                          |                                                                          |      1  2.0|
      Pigmentation, Hemosiderin            |                                                                          |      1  3.0|
      Vacuolization Cytoplasmic            |                                                                          |      3  2.7|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  54        |
      Hyperplasia                          | 2                       2                                                |     13  1.7|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  53        |
      Hyperplasia                          |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +                                 |  54        |
      Hyperplasia                          |                                                                          |      3  2.0|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  54        |
      Pars Distalis, Angiectasis           |                                                                          |      1  3.0|
      Pars Distalis, Cyst                  | 1     2     2  1              1        3                                 |     23  2.1|
      Pars Distalis, Hemorrhage            |                                        4                                 |      1  4.0|
      Pars Distalis, Hyperplasia           | 1     3     2           2     1     2                                    |     28  2.4|
      Pars Intermedia, Cyst                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  13                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |      A     |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Ultimobranchial Cyst                 |                                                                          |      1  2.0|
      C-Cell, Hyperplasia                  |    3              3                                                      |     19  2.2|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +                                 |  51        |
      Abscess                              |                                                                          |      1  2.0|
      Cyst                                 |             2                                                            |      4  2.3|
      Hyperplasia                          |                3                                                         |      2  3.0|
      Inflammation, Chronic                |                2                                                         |      7  1.7|
      Inflammation, Suppurative            |                2              2                                          |      5  1.4|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Atrophy                              |                                                                          |      2  2.5|
      Follicle, Cyst                       |                                                                          |      2  2.5|
      Periovarian Tissue, Cyst             |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Cervix, Abscess                      |                                                                          |      2  3.0|
      Cervix, Prolapse                     |                                                                          |      2  3.5|
      Endometrium, Hyperplasia, Cystic     | 2     2  2     4  2                 4                                    |     17  2.4|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   2        |
      Dilatation                           |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |          +                 +                                             |   8        |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Myelofibrosis                        |                                                                          |      1  2.0|
      Erythroid Cell, Hyperplasia          |                                                                          |      1  3.0|
      Myeloid Cell, Hyperplasia            |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Pancreatic, Hematopoietic Cell       |                                                                          |            |
          Proliferation                    |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Hyperplasia, Plasma Cell             |                                                                          |      4  3.3|
      Sinus, Ectasia                       |       2                                                                  |      3  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  A  +  +  +  +                                 |  53        |
      Congestion                           |                         4                                                |      1  4.0|
      Hyperplasia, Macrophage              |                                                                          |      2  2.5|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  14                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |      A     |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Sinus, Ectasia                       |       3  2        1           2                                          |      6  2.2|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Hematopoietic Cell Proliferation     |                                                                          |      2  3.0|
      Pigmentation, Hemosiderin            |                                        2                                 |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  52        |
      Cyst                                 |       2                                                                  |      4  2.3|
      Arteriole, Mediastinum, Inflammation,|                                                                          |            |
           Chronic                         | 4                                                                        |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Cyst                                 | 3  4                 3     4  3  4                                       |     16  3.3|
      Hyperplasia                          | 3        2  2  3  3  3     3  2  1  2                                    |     36  2.4|
      Duct, Fibrosis                       |                                     3                                    |      1  3.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Cyst Epithelial Inclusion            |                                                                          |      1     |
      Ulcer                                |                                                                          |      2  2.5|
      Subcutaneous Tissue, Inflammation,   |                                                                          |            |
           Chronic                         |                                                                          |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Compression                          |                      X                 X                                 |      7     |
      Meninges, Hemorrhage                 |                                     1                                    |      1  1.0|
      Pons, Hematocyst                     |                                                                          |      1  3.0|
      Ventricle, Dilatation                |                                        3                                 |      2  3.0|
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +                             +                                 |   8        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia, Macrophage              |                                                                          |      1  3.0|
      Hyperplasia, Adenomatous             |                                                                          |      1  1.0|
      Pigmentation, Hemosiderin            |                            1                                             |      1  1.0|
      Interstitium, Inflammation, Chronic  |    1                                                                     |      3  1.3|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  15                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 6| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 1| 8| 3| 3| 3| 3| 2| 3| 2| 8| 7| 5|                             |            |
                                           | 1| 0| 9| 0| 6| 1| 0| 0| 0| 9| 1| 9| 5| 6| 8|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|                             |      A     |
    VEHICLE                                | 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Pleura, Inflammation, Chronic        |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Inflammation, Chronic                |             3           2           2                                    |      7  2.0|
      Inflammation, Suppurative            |                                                                          |      1  3.0|
      Lumen, Foreign Body                  |                                                                          |      1  2.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         | 2  1     2     3     2  2     2  2                                       |     39  1.7|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                                                                          |      1  2.0|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         | 3  2  3  2  2  3  3  3  2  2  3  3  2  2                                 |     52  2.1|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Inflammation, Chronic                |                                                                          |      3  1.3|
      Glands, Cyst                         |                   2                                                      |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   2        |
      Retina, Atrophy                      |                                                                          |      2  3.5|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
      Inflammation, Chronic                |                                                                          |      2  2.0|
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Inflammation, Chronic                |    1  1     1        1                                                   |     17  1.2|
      Mineralization                       |    1                                                                     |      3  1.0|
      Nephropathy                          | 2  2  2  2  1  2  2  2  1  2  1  2     1                                 |     47  2.0|
      Pelvis, Dilatation                   |                                                                          |      1  2.0|
      Renal Tubule, Inflammation,          |                                                                          |            |
          Suppurative                      |                                                                          |      2  1.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Inflammation, Chronic                |                                                                          |      5  1.2|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  16                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +        +           A  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +        +           A  +     +                       A        +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |    3        1  2  1  1  2        2           2  4  4  2     2  3         |             
      Clear Cell Focus                     |                                                    2           2         |             
      Congestion                           |                                                                2         |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Cystic                 |                                                                          |             
      Eosinophilic Focus                   |                                                                          |             
      Fatty Change                         |                                                          2        3      |             
      Focal Cellular Change                |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Hepatodiaphragmatic Nodule           | X  X                                         X                          X|             
      Inflammation, Chronic                |    1        2  2  1  1  1     1  2           2     2  1        1        1|             
      Mineralization                       |                                                                          |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis, Coagulative                |                                                          3               |             
      Bile Duct, Hyperplasia               | 1  2           2  1  1  2     1  2           3     3           1  1  2  2|             
      Centrilobular, Atrophy               |                                                          4           3   |             
      Sinusoid, Dilatation                 |                                                    1                     |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +                    +        +           +   |             
      Arteriole, Degeneration, Hyaline     |                                                                          |             
      Arteriole, Inflammation, Chronic     |                                                                          |             
      Fat, Inflammation, Chronic           |                                                 1                    2   |             
      Fat, Inflammation, Granulomatous     |                                                                      2   |             
      Fat, Mineralization                  |                                                                          |             
      Fat, Necrosis                        |                            2                                         2   |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +        +           +  +     +                       +        +  +  +|             
      Atrophy                              |                                                                          |             
      Duct, Necrosis, Coagulative          |                                                                          |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +        M           +  +     +                       +        +  +  +|             
      Atrophy, Focal                       |                                                                          |             
      Duct, Ectasia                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  17                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Duct, Inflammation, Chronic          |                                                                          |             
      Duct, Metaplasia, Squamous           |    1                                                                     |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +        +           +  +     +                       +        +  +  +|             
      Acanthosis                           |                                                                      3   |             
      Hyperkeratosis                       |                                                                      3   |             
      Inflammation, Acute                  |                                                                      4   |             
      Ulcer                                |                            4                                      3      |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +        +           +  +     +                       +        +  +  +|             
      Inflammation, Acute                  |                                                                      4   |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                       +                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |             +                                            +               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +        +           +  +     +                       +        +  +  +|             
      Cardiomyopathy                       | 1  1        1           2  2     1                                2     2|             
      Atrium, Thrombosis                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                              3              3            |             
      Cyst                                 |                                                                          |             
      Degeneration, Fatty, Focal           |                         1                    4                          1|             
      Hematopoietic Cell Proliferation     |                      2  1                                                |             
      Hyperplasia                          |                   1                          4     3                    1|             
      Hypertrophy                          |                                                                          |             
      Necrosis, Coagulative                |                                                                          |             
      Vacuolization Cytoplasmic            |                            2                                             |             
      Capsule, Hyperplasia                 |                                  1                                       |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                              1  1                        |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +        +           M  +     +                       M        +  +  +|             
      Hyperplasia                          | 2                                                                 3      |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                         2|             
      Pars Distalis, Angiectasis           |                                                    3                     |             
      Pars Distalis, Cyst                  |                   1  3     2                          2        3         |             
      Pars Distalis, Hyperplasia           |    3              3  3                          1     3        3         |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Ultimobranchial Cyst                 |                                                                          |             
      C-Cell, Hyperplasia                  |                                              4        3        3        3|             
      Follicle, Cyst                       |                                                          1               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  18                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | M  +        +           +  M  M  +                       +        +  +  +|             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                                                                   1      |             
      Inflammation, Granulomatous          |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Pigmentation, Hemosiderin            |                                                          3               |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +        +           +  +     +                       +        +  +  +|             
      Atrophy                              |                                                                          |             
      Corpus Luteum, Cyst                  |                                                                          |             
      Follicle, Cyst                       |                                                                          |             
      Periovarian Tissue, Cyst             |                                                                         4|             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                            2                                             |             
      Cervix, Abscess                      |                                                                   3     3|             
      Cervix, Inflammation, Proliferative  |                                                                          |             
      Endometrium, Hyperplasia, Cystic     |                            2                                   2         |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                         +|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                                                                      +   |             
      Neutrophilia                         |                                                                          |             
      Thrombocytopenia                     |                                                                          |             
      Erythrocyte, Poikilocytosis          |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +        +           +  +     +                       +        +  +  +|             
      Myelofibrosis                        |                                                                      3   |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +        +           +  +     +                       +        +  +  +|             
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |             
      Mediastinal, Sinus, Ectasia          |                                                                          |             
      Pancreatic, Sinus, Ectasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +        M           +  +     +                       +        +  +  +|             
      Hyperplasia, Macrophage              |                                  2                                       |             
      Hyperplasia, Plasma Cell             |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +        +           +  +     +                       +        +  +  +|             
      Hemorrhage                           |                                                                          |             
      Sinus, Ectasia                       |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                         2  3                                            3|             
      Infarct                              |                                                                          |             
      Inflammation, Chronic                |                   1                                                      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  19                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +        +           +  +     +           M           +        +  +  +|             
      Cyst                                 |                                                                         2|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                               2              4           3              4|             
      Hyperplasia                          | 2  3           1  2  3     2  2  2              3  2  1  2  3  2  3      |             
      Mineralization                       |                                                                      2   |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +        +           +  +     +                       +        +  +  +|             
      Abscess                              |                                  3                                       |             
      Cyst Epithelial Inclusion            |                                                                          |             
      Inflammation, Chronic                | 2  2                                                                     |             
      Ulcer                                |                                  3                                       |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +        +           +  +     +                       +        +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +        +           +  +     +                       +        +  +  +|             
      Compression                          | X                                X                                X      |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |             +              +                                         +   |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +        +           +  +     +                       +        +  +  +|             
      Congestion                           |             3                                                            |             
      Hyperplasia, Macrophage              |                                                          3               |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +        +           +  +     +                       +        +  +  +|             
      Exudate                              |                                                                          |             
      Inflammation, Chronic                |                                                                   3      |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 1           2                                                     2     1|             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 3  1        2              1                                      2     1|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +        +           +  +     +                       +        +  +  +|             
      Inflammation, Chronic                |                                                                          |             
      Glands, Cyst                         | 2                                                                        |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  20                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 7| 7| 7| 5| 4| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 6| 6| 6|             
                             DAY ON TEST   | 2| 7| 5| 5| 7| 3| 3| 3| 9| 8| 3| 2| 5| 5| 5| 3| 3| 3| 3| 7| 3| 2| 6| 5| 2|             
                                           | 1| 2| 8| 8| 3| 1| 0| 0| 5| 7| 1| 4| 8| 8| 8| 1| 1| 1| 0| 6| 0| 9| 7| 5| 5|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 5|             
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                M                                                         |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +        +  +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Inflammation, Chronic                | 2              1                                                        1|             
      Mineralization                       |                                                                          |             
      Nephropathy                          | 4              2     1  2  1  3  2           2  1  2  1        2  3  1  2|             
      Pelvis, Dilatation                   |                                                                          |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +        +           +  +     +                       +        +  +  M|             
      Inflammation, Chronic                |                                                                      2   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  21                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  |       +  A  +        A  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  |       +  +  +        +  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  |       +  A  +        +  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                |       +  A  +        A  +              A  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Basophilic Focus                     | 4  3  3        3  3  2  3     3  4  2  4     1  3        3     3  2     3|             
      Clear Cell Focus                     |                      3           X     3                                 |             
      Congestion                           |                                                                          |             
      Cytomegaly                           |                                  1                                       |             
      Degeneration, Cystic                 |                                                             2            |             
      Eosinophilic Focus                   |                         3                                   2            |             
      Fatty Change                         |          2  2     2                       2        2  2                  |             
      Focal Cellular Change                |                                                                          |             
      Hematopoietic Cell Proliferation     |                                  1                                       |             
      Hemorrhage                           |                                                                          |             
      Hepatodiaphragmatic Nodule           |    X              X              X                             X         |             
      Inflammation, Chronic                | 2              1  2  2  1           1  2                       1        1|             
      Mineralization                       |                1                 1                       3               |             
      Mixed Cell Focus                     |                                        4                                 |             
      Necrosis, Coagulative                |          1                                            2                  |             
      Bile Duct, Hyperplasia               | 2  3  3           2              1  1  2              2  2     1  1     1|             
      Centrilobular, Atrophy               |                                                                          |             
      Sinusoid, Dilatation                 |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +           +                    +                    +  +     +|             
      Arteriole, Degeneration, Hyaline     |                                                                          |             
      Arteriole, Inflammation, Chronic     |                                                                          |             
      Fat, Inflammation, Chronic           |                      1                    3                    4         |             
      Fat, Inflammation, Granulomatous     |                                                                          |             
      Fat, Mineralization                  |                                                                         1|             
      Fat, Necrosis                        |                                                                2        2|             
                                            __________________________________________________________________________|             
   Pancreas                                |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Atrophy                              |       1                                                                  |             
      Duct, Necrosis, Coagulative          |                                                                3         |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                      M                                            +      |             
      Hyperkeratosis                       |                                                                   2      |             
      Inflammation, Chronic                |                                                                   3      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         |       +  +  +        M  +              +  +        +  +  +     +  +     +|             
      Atrophy, Focal                       |                                                                          |             
      Duct, Ectasia                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  22                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Duct, Inflammation, Chronic          |                                                                          |             
      Duct, Metaplasia, Squamous           |                                                       1                  |             
                                            __________________________________________________________________________|             
   Stomach                                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Inflammation, Acute                  |                                                                          |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Inflammation, Acute                  |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |          +                                                               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Cardiomyopathy                       |          2           2  1              2  2           1  1     2  2     1|             
      Atrium, Thrombosis                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Angiectasis                          | 3                                                                        |             
      Cyst                                 |                                                                          |             
      Degeneration, Fatty, Focal           |                                        4        3     2  1               |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hyperplasia                          |                2        1                             2           3     2|             
      Hypertrophy                          |                                                                          |             
      Necrosis, Coagulative                |       2     3                                                            |             
      Vacuolization Cytoplasmic            |                                                                          |             
      Capsule, Hyperplasia                 |                                        1                                 |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Hyperplasia                          |                                                                1        1|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       |       +  +  +        M  +     M        +  +        M  +  +  M  +  +     +|             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Cyst                                 |                                                                          |             
      Pars Distalis, Angiectasis           |                                                    4                     |             
      Pars Distalis, Cyst                  |       2  2        2     1     2     3     2           3     2  2        3|             
      Pars Distalis, Hyperplasia           | 4  4  2        3        3     3     3  4  2  2              2  2         |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  M  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Ultimobranchial Cyst                 |                X                                                         |             
      C-Cell, Hyperplasia                  | 3  3  2     2  3                                      1     2            |             
      Follicle, Cyst                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  23                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          |       +  +  +  M     M  +     M        +  M        M  +  +     +  +     +|             
      Cyst                                 |                                                          2               |             
      Hyperplasia                          |                         3                                      2         |             
      Inflammation, Chronic                |          1                                                               |             
      Inflammation, Granulomatous          |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Pigmentation, Hemosiderin            |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Atrophy                              |                                                                          |             
      Corpus Luteum, Cyst                  |                                                          1               |             
      Follicle, Cyst                       |                                                                          |             
      Periovarian Tissue, Cyst             |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Inflammation, Suppurative            |                                                                          |             
      Cervix, Abscess                      |                         3                             3                  |             
      Cervix, Inflammation, Proliferative  |                                                                          |             
      Endometrium, Hyperplasia, Cystic     |    2           2  3     2     3  3  2        2  2        2  2            |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +  +  +                                      +  +           +      |             
      Neutrophilia                         |             2                                                            |             
      Thrombocytopenia                     |             3                                                            |             
      Erythrocyte, Poikilocytosis          |             3                                                            |             
                                            __________________________________________________________________________|             
   Bone Marrow                             |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Myelofibrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Mediastinal, Hyperplasia, Plasma Cell|                                                       2                  |             
      Mediastinal, Sinus, Ectasia          |                                                       1                  |             
      Pancreatic, Sinus, Ectasia           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                   2      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Hemorrhage                           |                                                                         3|             
      Sinus, Ectasia                       |                                                          2               |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                         3|             
      Infarct                              |                                                             4            |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  24                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Pigmentation, Hemosiderin            |             4        2                                                   |             
                                            __________________________________________________________________________|             
   Thymus                                  |       +  +  +        +  +        M  M  +  M        +  +  +     +  +     +|             
      Cyst                                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Cyst                                 | 3           3        3        3  3                 3                     |             
      Hyperplasia                          | 3  3     2  3  2  2  3  2     3  4  2  2     2  3  3  2  1  3  2        2|             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    |    +  +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Abscess                              |                                                                          |             
      Cyst Epithelial Inclusion            |    X                                                                     |             
      Inflammation, Chronic                |                                                                          |             
      Ulcer                                |                                                                         3|             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |          +                                                               |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Compression                          |             X        X                                                   |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +  +                             +                              |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    |       +  +  +  +     +  +              +  +        +  +  +     +  +     +|             
      Congestion                           |                         4                                                |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Exudate                              |                         X                                                |             
      Inflammation, Chronic                |                                                                2        2|             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         |       2  1  1           1              1           1  2  2     1  2     1|             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         |       2  2  2           2              2  2        2  2  2     1  2     1|             
                                            __________________________________________________________________________|             
   Trachea                                 |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Inflammation, Chronic                |          2                                               1               |             
      Glands, Cyst                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |             +                                                            |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |             +                                                            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  25                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 5| 7| 7| 7| 7| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 7| 4| 6|             
                             DAY ON TEST   | 3| 3| 2| 2| 6| 3| 3| 1| 0| 5| 3| 3| 2| 1| 4| 2| 2| 0| 5| 3| 2| 0| 0| 5| 5|             
                                           | 1| 1| 5| 4| 0| 1| 1| 9| 0| 8| 1| 0| 9| 0| 4| 9| 9| 8| 5| 3| 9| 0| 0| 8| 4|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 5| 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|             
    25 MG/KG                               | 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Inflammation, Chronic                |             3                                                            |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +     +|             
      Cyst                                 |                                                                          |             
      Inflammation, Chronic                |                         1        1  1           1     1     1     2      |             
      Mineralization                       |                         1                                                |             
      Nephropathy                          | 2  2  2  2  3  2  1     1     1  2  3  2  3  1  3  1  3  2  2     3     1|             
      Pelvis, Dilatation                   |                                           3                              |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         |       +  +  +        +  +              +  +        +  +  +     +  +     +|             
      Inflammation, Chronic                |             1                                            1               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  26                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |      A     |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               |       +              +  +        M     +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  |       +              +  +              +  +                              |  24        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  |       +              +  +              +  +                              |  26        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Small                         |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  |       +              +  +              +  +                              |  24        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                |       +              +  +              +  +                              |  23        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Basophilic Focus                     | 2  3           2  3           2  3  1  1                                 |     38  2.5|
      Clear Cell Focus                     |                                        2                                 |      6  2.4|
      Congestion                           |                                                                          |      1  2.0|
      Cytomegaly                           |                      2                                                   |      2  1.5|
      Degeneration, Cystic                 |                                                                          |      1  2.0|
      Eosinophilic Focus                   |                                                                          |      2  2.5|
      Fatty Change                         |                      4  2                                                |     10  2.3|
      Focal Cellular Change                |                   1                                                      |      1  1.0|
      Hematopoietic Cell Proliferation     |                         2                                                |      2  1.5|
      Hemorrhage                           |                      2                                                   |      1  2.0|
      Hepatodiaphragmatic Nodule           | X                             X                                          |     10     |
      Inflammation, Chronic                | 2  1  1        2              1  1  2  1                                 |     30  1.4|
      Mineralization                       |                                                                          |      3  1.7|
      Mixed Cell Focus                     |                                                                          |      1  4.0|
      Necrosis, Coagulative                |                                                                          |      3  2.0|
      Bile Duct, Hyperplasia               | 3  2           2     2  1     1  2  3  2  2                              |     36  1.8|
      Centrilobular, Atrophy               |                      2                                                   |      3  3.0|
      Sinusoid, Dilatation                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               | +     +                                   +                              |  13        |
      Arteriole, Degeneration, Hyaline     |       2                                                                  |      1  2.0|
      Arteriole, Inflammation, Chronic     |       2                                                                  |      1  2.0|
      Fat, Inflammation, Chronic           | 2                                                                        |      6  2.2|
      Fat, Inflammation, Granulomatous     |                                                                          |      1  2.0|
      Fat, Mineralization                  |                                                                          |      1  1.0|
      Fat, Necrosis                        |                                           2                              |      5  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                |       +              +  +              +  +                              |  28        |
      Atrophy                              |                                                                          |      1  1.0|
      Duct, Necrosis, Coagulative          |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pharynx                                 |                                                                          |   1        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  27                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |      A     |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Hyperkeratosis                       |                                                                          |      1  2.0|
      Inflammation, Chronic                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         |       +              +  +              +  +                              |  26        |
      Atrophy, Focal                       |                         2                                                |      1  2.0|
      Duct, Ectasia                        |                         2                                                |      1  2.0|
      Duct, Inflammation, Chronic          |                         1                                                |      1  1.0|
      Duct, Metaplasia, Squamous           |                         1                                                |      3  1.0|
                                            __________________________________________________________________________|____________|
   Stomach                                 |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    |       +              +  +              +  +                              |  28        |
      Acanthosis                           |                         2                                                |      2  2.5|
      Hyperkeratosis                       |                         2                                                |      2  2.5|
      Inflammation, Acute                  |                                                                          |      1  4.0|
      Ulcer                                |                                                                          |      2  3.5|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      |       +              +  +              +  +                              |  28        |
      Inflammation, Acute                  |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   3        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   |       +              +  +              +  +                              |  28        |
      Cardiomyopathy                       |       1                 2                                                |     20  1.6|
      Atrium, Thrombosis                   |                      X                                                   |      1     |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Angiectasis                          |                               3  3  3                                    |      6  3.0|
      Cyst                                 |                                           2                              |      1  2.0|
      Degeneration, Fatty, Focal           |       2                                                                  |      8  2.3|
      Hematopoietic Cell Proliferation     |                                                                          |      2  1.5|
      Hyperplasia                          |       1              3                                                   |     11  2.1|
      Hypertrophy                          |                   2                                                      |      1  2.0|
      Necrosis, Coagulative                |                      3                                                   |      3  2.7|
      Vacuolization Cytoplasmic            |                                                                          |      1  2.0|
      Capsule, Hyperplasia                 |                      1                                                   |      3  1.0|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Hyperplasia                          |       1           1           3  1                                       |      8  1.3|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       |       M           M  +  +        M     M  +                              |  22        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  28                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |      A     |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia                          |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +        +  +  +  +     +  +  +  +  +                              |  54        |
      Cyst                                 |                                                                          |      1  2.0|
      Pars Distalis, Angiectasis           |                                                                          |      2  3.5|
      Pars Distalis, Cyst                  |                      4                    3                              |     18  2.3|
      Pars Distalis, Hyperplasia           |       2           2  2              2                                    |     22  2.6|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  54        |
      Ultimobranchial Cyst                 |                                                                          |      1     |
      C-Cell, Hyperplasia                  |    1           4        2           2                                    |     15  2.5|
      Follicle, Cyst                       |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          |       +              +  +        +     +  +                              |  24        |
      Cyst                                 |                                                                          |      1  2.0|
      Hyperplasia                          |                                                                          |      2  2.5|
      Inflammation, Chronic                |                                                                          |      2  1.0|
      Inflammation, Granulomatous          |                                           3                              |      1  3.0|
      Inflammation, Suppurative            |                         1                                                |      1  1.0|
      Pigmentation, Hemosiderin            |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   |       +           +  +  +              +  +                              |  29        |
      Atrophy                              |                   3                                                      |      1  3.0|
      Corpus Luteum, Cyst                  |                                                                          |      1  1.0|
      Follicle, Cyst                       |                   4                                                      |      1  4.0|
      Periovarian Tissue, Cyst             |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Cervix, Abscess                      |                   4              3                                       |      6  3.2|
      Cervix, Inflammation, Proliferative  |                   4                                                      |      1  4.0|
      Endometrium, Hyperplasia, Cystic     | 3                 3                 4                                    |     16  2.4|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |                      +                 +  +                              |  10        |
      Neutrophilia                         |                                        X                                 |      2  2.0|
      Thrombocytopenia                     |                                                                          |      1  3.0|
      Erythrocyte, Poikilocytosis          |                                                                          |      1  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  29                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |      A     |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             |       +              +  +              +  +                              |  28        |
      Myelofibrosis                        |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +              +  +              +  +                              |  28        |
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |      1  2.0|
      Mediastinal, Sinus, Ectasia          |                                                                          |      1  1.0|
      Pancreatic, Sinus, Ectasia           |                                           4                              |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  |       +              +  M              +  +                              |  26        |
      Hyperplasia, Macrophage              |                                                                          |      1  2.0|
      Hyperplasia, Plasma Cell             |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  |       +              +  +              +  +                              |  28        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Sinus, Ectasia                       |       2                                                                  |      2  2.0|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Fibrosis                             | 2                                                                        |      1  2.0|
      Hematopoietic Cell Proliferation     |                         2                                                |      5  2.6|
      Infarct                              |                                                                          |      1  4.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Pigmentation, Hemosiderin            |                                                                          |      2  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  |       +              +  +     M  M  M  +  +                              |  27        |
      Cyst                                 |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Cyst                                 |                      2                 4                                 |     12  3.1|
      Hyperplasia                          | 2  2  2        4  3  3        2  3  2  3                                 |     45  2.4|
      Mineralization                       |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Skin                                    |       +              +  +     +        +  +                              |  30        |
      Abscess                              |                                                                          |      1  3.0|
      Cyst Epithelial Inclusion            |                                                                          |      1     |
      Inflammation, Chronic                |                                                                          |      2  2.0|
      Ulcer                                |                                                                          |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    |       +              +  +              +  +                              |  28        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                      +                                                   |   2        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   |       +              +  +              +  +                              |  28        |
      Compression                          |                         X                                                |      6     |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  30                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 4| 4| 7| 7| 7| 6| 6|                             |            |
                             DAY ON TEST   | 3| 2| 6| 5| 5| 3| 3| 0| 9| 5| 2| 2| 2| 7| 6|                             |            |
                                           | 0| 9| 8| 8| 8| 0| 0| 9| 2| 8| 9| 9| 9| 2| 1|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6|                             |      A     |
    25 MG/KG                               | 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                         +                                                |   7        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    |       +              +  +              +  +                              |  29        |
      Congestion                           |                                                                          |      2  3.5|
      Hyperplasia, Macrophage              |                                                                          |      1  3.0|
      Hyperplasia, Adenomatous             |                                        2                                 |      1  2.0|
      Interstitium, Inflammation, Chronic  |                                        1  1                              |      2  1.0|
                                            __________________________________________________________________________|____________|
   Nose                                    |       +              +  +              +  +                              |  28        |
      Exudate                              |                                                                          |      1     |
      Inflammation, Chronic                |       2                                                                  |      4  2.3|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         |       3              2                                                   |     17  1.5|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         |       3              3                                                   |     20  1.9|
                                            __________________________________________________________________________|____________|
   Trachea                                 |       +              +  +              +  +                              |  28        |
      Inflammation, Chronic                |                                                                          |      2  1.5|
      Glands, Cyst                         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
      Inflammation, Chronic                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +        +  +  +  +     +  +  +  +  +                              |  55        |
      Cyst                                 |                         3                                                |      1  3.0|
      Inflammation, Chronic                | 2  1  1                             2                                    |     14  1.3|
      Mineralization                       |                                                                          |      1  1.0|
      Nephropathy                          | 3  2           2  2  2  3     2  1  2  1  3                              |     47  2.0|
      Pelvis, Dilatation                   |                                                                          |      1  3.0|
      Transitional Epithelium, Hyperplasia,|                                                                          |            |
           Papillary                       |    2                                                                     |      1  2.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         |       +              +  +              +  +                              |  27        |
      Inflammation, Chronic                |                      1                                                   |      4  1.3|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  31                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  M     +  +  +  M     A  M  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Erosion                              |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +     +  +  +  +     A  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Basophilic Focus                     | 2  3     1        1  3  2                    2  3  2  3     1  2  1      |             
      Clear Cell Focus                     |          3                                      1                        |             
      Congestion                           |                                                                          |             
      Cytomegaly                           |                                     3                                    |             
      Fatty Change                         |                                                       3           1  2   |             
      Fibrosis, Focal                      |       2                                                                  |             
      Focal Cellular Change                |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hepatodiaphragmatic Nodule           |    X     X                                      X           X     X      |             
      Hyperplasia, Focal                   |                      2                                                   |             
      Inflammation, Chronic                |    2     1        2  1  1     1           1  1     1           2  1  1   |             
      Inflammation, Granulomatous          |    1                                                                     |             
      Mineralization                       |                                                                          |             
      Mixed Cell Focus                     |                      1                          2                        |             
      Necrosis, Coagulative                |                               3  2                                       |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    |                                                                          |             
      Bile Duct, Hyperplasia               | 2  3  1        2  1  2           2  2     1  2     1  2     1  3  1  1   |             
      Centrilobular, Atrophy               |       2                       4     3                                    |             
      Sinusoid, Dilatation                 |          2                                                               |             
                                            __________________________________________________________________________|             
   Mesentery                               |       +              +           +  +                 +                  |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Fat, Hemorrhage                      |                                                                          |             
      Fat, Inflammation, Acute             |                                                                          |             
      Fat, Inflammation, Chronic           |                                  2                                       |             
      Fat, Necrosis                        |                      2           2  1                 2                  |             
      Fat, Pigmentation, Hemosiderin       |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Focal Cellular Change                |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Atrophy, Focal                       |                                                                          |             
      Cytoplasmic Alteration               |    1                                                              1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  32                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    |                                                                          |             
      Duct, Inflammation, Chronic          |                         2                                                |             
      Duct, Metaplasia, Squamous           |    2              2                          2  1                        |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Cardiomyopathy                       | 3  1  2  2     2  2  2  1     2  1        1     1  1  1     1  1         |             
      Atrium, Inflammation, Chronic        |                                                                          |             
      Atrium, Thrombosis                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Accessory Adrenal Cortical Nodule    |    X                                                                     |             
      Angiectasis                          | 3                 3  1                                                   |             
      Atrophy                              |                                                                          |             
      Cyst                                 |                                                                          |             
      Degeneration, Fatty, Focal           |          2                                                           3   |             
      Degeneration, Focal                  |                                                                          |             
      Hematopoietic Cell Proliferation     |                               2                          1               |             
      Hyperplasia                          |          2              1        1                                3  2   |             
      Vacuolization Cytoplasmic            |                                     3     2                              |             
      Capsule, Hyperplasia                 |                                  1                                       |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |       1                                      3              3     2      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +  M     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |          4                                                               |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |                                                                          |             
      Pars Distalis, Cyst                  |    3  X        3     3  2                       3     3     4            |             
      Pars Distalis, Hyperplasia           |          3     3  3  4  2     3  2  3              4  4  3        4      |             
      Rathke's Cleft, Crystals             |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      C-Cell, Hyperplasia                  |          1                                   1              1     2  4   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  33                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +     +  +  +  +     +  M  +     M  +  +  +  M  +  +  +  +  +   |             
      Cyst                                 |                3              2                 3           3            |             
      Inflammation, Chronic                | 2              2     2                                                   |             
      Inflammation, Granulomatous          |                                                                          |             
      Inflammation, Suppurative            |       1                                                        3         |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Corpus Luteum, Cyst                  |                                                                          |             
      Periovarian Tissue, Cyst             |                   3                                                      |             
                                            __________________________________________________________________________|             
   Oviduct                                 |                                           +           +                  |             
      Inflammation, Chronic                |                                           2                              |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Suppurative            |                                                                          |             
      Cervix, Abscess                      |                                                             3            |             
      Cervix, Inflammation, Proliferative  |                                                                          |             
      Cervix, Epithelium, Degeneration,    |                                                                          |             
           Mucoid                          |                                                                          |             
      Endometrium, Hyperplasia, Cystic     |          2        3     2        2           2           2  3            |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |       +        +                    +                 +           +      |             
      Neutrophilia                         |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Erythroid Cell, Hyperplasia          |                               2                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Mediastinal, Hyperplasia, Macrophage |                                     3                                    |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                                          3               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  M     +  +  +  +     +  +  +     M  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia, Lymphoid                |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Sinus, Ectasia                       | 2                                                                        |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Congestion                           |                               4                                          |             
      Hyperplasia, Plasma Cell             |                                  3                                       |             
      Sinus, Ectasia                       |                                              2                    4      |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                               4                          2               |             
      Infarct                              |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  M  +   |             
      Cyst                                 |                   2                          2  2              1         |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  34                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +     M  +  +  +  +  +  +  +  +  +   |             
      Abscess                              |                               1                                          |             
      Cyst                                 |          4     4                             4  3                        |             
      Hyperplasia                          |    3  2  2              3     2     2        4  2           3     3      |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Cyst Epithelial Inclusion            |                                                             X            |             
      Ulcer                                |    3                                                                     |             
      Subcutaneous Tissue, Cyst            |                                                                      4   |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Compression                          |                                                                          |             
      Cerebrum, Mineralization             |                                  1                                       |             
      Ventricle, Dilatation                |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                           +           +              +   |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Edema                                |                                  2                                       |             
      Hyperplasia, Macrophage              |                                                 2                        |             
      Hyperplasia, Adenomatous             |                                                 2              2         |             
      Interstitium, Inflammation, Chronic  |                                              1                           |             
      Interstitium, Inflammation,          |                                                                          |             
          Granulomatous                    |                                                                   2      |             
      Pleura, Inflammation, Chronic        |                         1                                                |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Hemorrhage                           |                                                                          |             
      Inflammation, Chronic                |       3                          3                    2                  |             
      Nasolacrimal Duct, Cyst              |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 2  2  1  2              2        2           2  2     1  1     2     2   |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 3  3  2  3     3     2  2        2           4  3  3  1  1  4  2  2  2   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Glands, Cyst                         |                2     3                                                   |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                +     +   |             
      Hemorrhage                           |                                                                          |             
      Cornea, Proliferation                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  35                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 6| 4| 7| 6| 6| 4| 3| 7| 7| 7| 6| 5| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 2| 2| 9| 8| 5| 3| 3| 3| 5| 5| 1| 5| 3| 5| 4| 3| 3| 2| 5| 9| 3| 3| 2| 5| 5|             
                                           | 9| 9| 5| 7| 8| 1| 1| 0| 8| 8| 6| 8| 8| 8| 3| 0| 0| 9| 2| 8| 1| 0| 9| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Retina, Atrophy                      |                                                                4         |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                      +   |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +     +  +  +  +  +  +  +  +  +  +   |             
      Cyst                                 | 2                                                                        |             
      Inflammation, Chronic                | 1        2           1                    1  1                 1  1      |             
      Mineralization                       | 2                                                        1  1            |             
      Necrosis, Coagulative                |                                                                          |             
      Nephropathy                          | 2     1  4     1  1  2           1  2     2  2  2  2  2     2  2  2      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  M  +     +  +  +     +  +  +  +  +  M  +  +  +  +   |             
      Inflammation, Chronic                |                                     1     1                              |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  36                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Erosion                              |                                                             2            |             
      Inflammation, Suppurative            |                                                             2            |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +     +      |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Basophilic Focus                     |                2              2  1  2           1     3           1      |             
      Clear Cell Focus                     |                                     X                                    |             
      Congestion                           |                                                                          |             
      Cytomegaly                           |                   2                                                      |             
      Fatty Change                         |          2                                                     2  2      |             
      Fibrosis, Focal                      |                                                                          |             
      Focal Cellular Change                |                                  2                                       |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hepatodiaphragmatic Nodule           |                X              X  X                                X      |             
      Hyperplasia, Focal                   |                                                                          |             
      Inflammation, Chronic                | 1           1  1  3           1  1     1     2        1                  |             
      Inflammation, Granulomatous          |                                                                          |             
      Mineralization                       |                                                                          |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis, Coagulative                |                                           3                              |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    |          3                                                               |             
      Bile Duct, Hyperplasia               | 1        2     2  3           2  2     3  3  4  1  2           2         |             
      Centrilobular, Atrophy               |       1  2        3                    2  2                              |             
      Sinusoid, Dilatation                 | 2                                                                 1      |             
                                            __________________________________________________________________________|             
   Mesentery                               | M  +              +              +     +  +           +        +         |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Fat, Hemorrhage                      |                                                       3                  |             
      Fat, Inflammation, Acute             |                                                       4                  |             
      Fat, Inflammation, Chronic           |                   1              2                                       |             
      Fat, Necrosis                        |    2                                                  2                  |             
      Fat, Pigmentation, Hemosiderin       |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Focal Cellular Change                |                                  3                                       |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Atrophy, Focal                       |    2                                                                     |             
      Cytoplasmic Alteration               |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  37                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    | 4                                                                        |             
      Duct, Inflammation, Chronic          |          1  1                    1        1              1               |             
      Duct, Metaplasia, Squamous           |    2     1  1                          1  1              1               |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Acanthosis                           |                                                             3     3      |             
      Hyperkeratosis                       |                                                             3     3      |             
      Inflammation, Chronic                |                                                                   3      |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  A  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +  +                    +           +                     |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cardiomyopathy                       | 1  1  2        3  2           2  1  1  2  2  2  1  1  1           2      |             
      Atrium, Inflammation, Chronic        |                                     2                                    |             
      Atrium, Thrombosis                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Angiectasis                          |                                                                          |             
      Atrophy                              |    3                                                                     |             
      Cyst                                 |                                                                2         |             
      Degeneration, Fatty, Focal           |                   1                                1     4               |             
      Degeneration, Focal                  |                               1                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hyperplasia                          |          2                                      1  2     3               |             
      Vacuolization Cytoplasmic            |                                                             3     2      |             
      Capsule, Hyperplasia                 |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  M  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |                   1                          2  1  3        2            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |                                                          3               |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  I  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |             2                                                            |             
      Pars Distalis, Cyst                  | 3                 2              2              2  3  2     3            |             
      Pars Distalis, Hyperplasia           |                   2              4  2  4        4  4  2     2     3      |             
      Rathke's Cleft, Crystals             |                                        2                                 |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      C-Cell, Hyperplasia                  |                3                 4  4                       4  2         |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  38                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cyst                                 |    2                                            2                        |             
      Inflammation, Chronic                |                                              1                           |             
      Inflammation, Granulomatous          |    2                                                                     |             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Corpus Luteum, Cyst                  |                                                                          |             
      Periovarian Tissue, Cyst             |                                                                          |             
                                            __________________________________________________________________________|             
   Oviduct                                 |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Suppurative            |       1                                                                  |             
      Cervix, Abscess                      |                                                                3         |             
      Cervix, Inflammation, Proliferative  | 3                                                                        |             
      Cervix, Epithelium, Degeneration,    |                                                                          |             
           Mucoid                          | 4                                                                        |             
      Endometrium, Hyperplasia, Cystic     | 2                             4                 3  4  2  1               |             
                                            __________________________________________________________________________|             
   Vagina                                  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +  +                    +  +        +           +         |             
      Neutrophilia                         |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Erythroid Cell, Hyperplasia          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Mediastinal, Hyperplasia, Macrophage |                                                                          |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +              +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia, Lymphoid                |                                                                          |             
      Hyperplasia, Plasma Cell             |                3                                                         |             
      Sinus, Ectasia                       |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +              +  +  +  +  +  +  +  +  +  +  +  +      |             
      Congestion                           |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Sinus, Ectasia                       |                2                                                         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Infarct                              |                                                    4                     |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  M  M           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cyst                                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  39                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Abscess                              |                                                                          |             
      Cyst                                 | 4                             3        3        3        3        4      |             
      Hyperplasia                          | 3     2  3  2     2              3           3     3  3  3  2            |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cyst Epithelial Inclusion            |                                                                          |             
      Ulcer                                |                                                                          |             
      Subcutaneous Tissue, Cyst            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |    +                                                           +         |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Compression                          |                                                                   3      |             
      Cerebrum, Mineralization             |                                                                          |             
      Ventricle, Dilatation                |                                                                   3      |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                +  +           +        +                       +         |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Edema                                |                                                                          |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                                                          |             
      Interstitium, Inflammation,          |                                                                          |             
          Granulomatous                    |                                                                          |             
      Pleura, Inflammation, Chronic        |                               2                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hemorrhage                           |                                                                          |             
      Inflammation, Chronic                |          2                                                               |             
      Nasolacrimal Duct, Cyst              |    1                                                                     |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 2  2     2        1           2     1  1           2     2  1  2         |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 3  1     1     3  1           3  2  3  4           2  4  3  1  2         |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Glands, Cyst                         |                               2                       4                  |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |          +                                                        +      |             
      Hemorrhage                           |                                                                   2      |             
      Cornea, Proliferation                |                                                                   2      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  40                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 4| 4| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 6| 7| 6| 5| 4| 4|             
                             DAY ON TEST   | 2| 1| 1| 9| 3| 2| 0| 5| 5| 5| 3| 3| 3| 3| 9| 3| 3| 2| 2| 5| 0| 6| 8| 5| 5|             
                                           | 9| 4| 1| 4| 4| 9| 7| 8| 8| 8| 1| 0| 0| 0| 7| 0| 0| 9| 9| 8| 3| 9| 8| 8| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
    50 MG/KG                               | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Retina, Atrophy                      |                                                                   4      |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cyst                                 |                                                                          |             
      Inflammation, Chronic                | 2              1              2              1  1     1  1  2            |             
      Mineralization                       |                                        1                                 |             
      Necrosis, Coagulative                |                   2                                                      |             
      Nephropathy                          | 3  1  1  2     2              3  2  2  2  2  3  2  1  2  4  4     4      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | M  +  +  +  +  +  +           +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Chronic                |                                                                          |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                     1                                    |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  41                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |      A     |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  51        |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Erosion                              |                                                                          |      1  2.0|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  51        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Basophilic Focus                     | 3  2  2  2     1  1        2  2  2  3                                    |     30  1.9|
      Clear Cell Focus                     |       2        1                                                         |      5  1.8|
      Congestion                           |                            3                                             |      1  3.0|
      Cytomegaly                           |                                                                          |      2  2.5|
      Fatty Change                         |                1           2              3                              |      9  2.0|
      Fibrosis, Focal                      |                                  2                                       |      2  2.0|
      Focal Cellular Change                |                                                                          |      1  2.0|
      Hematopoietic Cell Proliferation     |                1                                                         |      1  1.0|
      Hepatodiaphragmatic Nodule           |                      X           X                                       |     11     |
      Hyperplasia, Focal                   |                                                                          |      1  2.0|
      Inflammation, Chronic                | 1  1  1        1  1  1     1     3  1     1                              |     31  1.3|
      Inflammation, Granulomatous          |                                                                          |      1  1.0|
      Mineralization                       |                      2                                                   |      1  2.0|
      Mixed Cell Focus                     |                                                                          |      2  1.5|
      Necrosis, Coagulative                |                                        3                                 |      4  2.8|
      Arteriole, Inflammation,             |                                                                          |            |
          Proliferative                    |                                                                          |      1  3.0|
      Bile Duct, Hyperplasia               | 1  2  1  3     3  1  1  1  1  2  3     3  2                              |     41  1.9|
      Centrilobular, Atrophy               |                         2              3                                 |     10  2.4|
      Sinusoid, Dilatation                 |                                                                          |      3  1.7|
                                            __________________________________________________________________________|____________|
   Mesentery                               |       +           +           +           +                              |  16        |
      Pigmentation, Hemosiderin            |                   3                                                      |      1  3.0|
      Fat, Hemorrhage                      |                               2                                          |      2  2.5|
      Fat, Inflammation, Acute             |                                                                          |      1  4.0|
      Fat, Inflammation, Chronic           |       2           3                                                      |      5  2.0|
      Fat, Necrosis                        |                                           2                              |      7  1.9|
      Fat, Pigmentation, Hemosiderin       |                   3                                                      |      1  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  42                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |      A     |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Focal Cellular Change                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Atrophy, Focal                       |       1                 1                                                |      3  1.3|
      Cytoplasmic Alteration               |                                                                          |      2  1.0|
      Arteriole, Inflammation,             |                                                                          |            |
          Proliferative                    |                                                                          |      1  4.0|
      Duct, Inflammation, Chronic          |                                                                          |      6  1.2|
      Duct, Metaplasia, Squamous           |                   1                       1                              |     12  1.3|
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Acanthosis                           |                                                                          |      2  3.0|
      Hyperkeratosis                       |                                                                          |      2  3.0|
      Inflammation, Chronic                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                         +                                                |   5        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Cardiomyopathy                       | 1  1  2        2  1  1  1     1  1  1  2                                 |     42  1.5|
      Atrium, Inflammation, Chronic        |                                                                          |      1  2.0|
      Atrium, Thrombosis                   |                            X              X                              |      2     |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Accessory Adrenal Cortical Nodule    |    X                                                                     |      2     |
      Angiectasis                          |                   3                                                      |      4  2.5|
      Atrophy                              |                                                                          |      1  3.0|
      Cyst                                 | 4        1                                                               |      3  2.3|
      Degeneration, Fatty, Focal           |       2                       1     1                                    |      8  1.9|
      Degeneration, Focal                  |                                                                          |      1  1.0|
      Hematopoietic Cell Proliferation     |                                                                          |      2  1.5|
      Hyperplasia                          |                         1     2  1                                       |     12  1.8|
      Vacuolization Cytoplasmic            | 4                          3              2                              |      7  2.7|
      Capsule, Hyperplasia                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Hyperplasia                          |    2                    1                                                |     11  1.9|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  43                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |      A     |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Hyperplasia                          |                                                                          |      2  3.5|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Hyperplasia                          |                                                                          |      1  2.0|
      Pars Distalis, Cyst                  | 2  2              2     3  3                                             |     20  2.6|
      Pars Distalis, Hyperplasia           | 2  1     1              3  3                                             |     26  2.9|
      Rathke's Cleft, Crystals             |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      C-Cell, Hyperplasia                  | 2     3              4              1                                    |     14  2.6|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  52        |
      Cyst                                 |    3                       2     2                                       |      9  2.4|
      Inflammation, Chronic                |                                  1                                       |      5  1.6|
      Inflammation, Granulomatous          |                                                                          |      1  2.0|
      Inflammation, Suppurative            |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Corpus Luteum, Cyst                  |       1                                                                  |      1  1.0|
      Periovarian Tissue, Cyst             |       4                                                                  |      2  3.5|
                                            __________________________________________________________________________|____________|
   Oviduct                                 |                                                                          |   2        |
      Inflammation, Chronic                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Inflammation, Suppurative            |                                     2                                    |      2  1.5|
      Cervix, Abscess                      |       3                             3                                    |      4  3.0|
      Cervix, Inflammation, Proliferative  |                                                                          |      1  3.0|
      Cervix, Epithelium, Degeneration,    |                                                                          |            |
           Mucoid                          |                                                                          |      1  4.0|
      Endometrium, Hyperplasia, Cystic     |                         3        4                                       |     15  2.6|
                                            __________________________________________________________________________|____________|
   Vagina                                  |                                  +                                       |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |          +     +        +  +           +  +                              |  18        |
      Neutrophilia                         |                X           X                                             |      2     |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Erythroid Cell, Hyperplasia          |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  44                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |      A     |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Mediastinal, Hyperplasia, Macrophage |                                                                          |      1  3.0|
      Mediastinal, Pigmentation,           |                                                                          |            |
          Hemosiderin                      |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  52        |
      Hyperplasia, Lymphoid                |                      3                                                   |      1  3.0|
      Hyperplasia, Plasma Cell             |                            4                                             |      2  3.5|
      Sinus, Ectasia                       |                                        2                                 |      2  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Congestion                           |                                                                          |      1  4.0|
      Hyperplasia, Plasma Cell             |                                                                          |      1  3.0|
      Sinus, Ectasia                       |                                                                          |      3  2.7|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Fibrosis                             |          2              1                                                |      2  1.5|
      Hematopoietic Cell Proliferation     |                                                                          |      2  3.0|
      Infarct                              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +  +  M  +  +  +  +                              |  51        |
      Cyst                                 |                         1                                                |      5  1.6|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  54        |
      Abscess                              |                                                                          |      1  1.0|
      Cyst                                 |                4  4     2              2                                 |     14  3.4|
      Hyperplasia                          |    3     2        3  2        3  3  2  3  1                              |     30  2.6|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Cyst Epithelial Inclusion            |                                                                          |      1     |
      Ulcer                                |                            3                                             |      2  3.0|
      Subcutaneous Tissue, Cyst            |                                                                          |      1  4.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Compression                          |                                  X                                       |      2  3.0|
      Cerebrum, Mineralization             |                                                                          |      1  1.0|
      Ventricle, Dilatation                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +              +              +  +                              |  12        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  45                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 6| 4| 7| 7| 7| 7| 5| 7| 7| 7| 7| 4|                             |            |
                             DAY ON TEST   | 3| 3| 2| 7| 5| 3| 2| 2| 2| 9| 3| 3| 3| 3| 9|                             |            |
                                           | 1| 0| 9| 6| 8| 0| 9| 9| 9| 0| 1| 1| 0| 0| 2|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS FEMALE                 | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|                             |      A     |
    50 MG/KG                               | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Edema                                |                                                                          |      1  2.0|
      Hyperplasia, Macrophage              |                                                                          |      1  2.0|
      Hyperplasia, Adenomatous             |                                                                          |      2  2.0|
      Interstitium, Inflammation, Chronic  |                                                                          |      1  1.0|
      Interstitium, Inflammation,          |                                                                          |            |
          Granulomatous                    |                                                                          |      1  2.0|
      Pleura, Inflammation, Chronic        |                1                                                         |      3  1.3|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Hemorrhage                           |                               2                                          |      1  2.0|
      Inflammation, Chronic                |                                                                          |      4  2.5|
      Nasolacrimal Duct, Cyst              |                                                                          |      1  1.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         |       2              1     3        1  2                                 |     28  1.7|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         | 3     2              1  2  2  3  3  3  3                                 |     40  2.4|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Glands, Cyst                         |                   1              2                                       |      6  2.3|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                            +  +                                          |   6        |
      Hemorrhage                           |                            2  2                                          |      3  2.0|
      Cornea, Proliferation                |                                                                          |      1  2.0|
      Retina, Atrophy                      |                                                                          |      2  4.0|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                            +                                             |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +  +  +  +  +  +  +                              |  55        |
      Cyst                                 |                                                                          |      1  2.0|
      Inflammation, Chronic                |       2           1  1                                                   |     18  1.3|
      Mineralization                       |                                                                          |      4  1.3|
      Necrosis, Coagulative                |                                                                          |      1  2.0|
      Nephropathy                          | 1  1  3  1     3  3  3  1  2  2  2     2  2                              |     46  2.1|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +  +  +  +  +  +  M                              |  51        |
      Inflammation, Chronic                | 1                                                                        |      3  1.0|
      Transitional Epithelium, Hyperplasia,|                                                                          |            |
           Papillary                       |                                                                          |      1  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  46                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  M  +  +     A  +  +  +  +  +  +  A  +  +  +  +  A  +   |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Basophilic Focus                     | 1     1           1                 2  2     1                           |             
      Clear Cell Focus                     |                                                                          |             
      Concretion                           |                                                                          |             
      Cytomegaly                           |                                                             2            |             
      Degeneration, Cystic                 |          2     2     2  2        2  2        1  2           3  1         |             
      Eosinophilic Focus                   |                                     1        2     2                     |             
      Fatty Change                         |                                                          2           2   |             
      Hematopoietic Cell Proliferation     |                                  1                                2      |             
      Hepatodiaphragmatic Nodule           | X                                                  X  X                  |             
      Hyperplasia, Focal                   |                                                                          |             
      Inflammation, Chronic                | 3     1           1     1           2        1           2               |             
      Mixed Cell Focus                     |                                     3  2                                 |             
      Necrosis, Coagulative                |                2                          2           3  2               |             
      Bile Duct, Dilatation                |                                                                          |             
      Bile Duct, Hyperplasia               | 3  2  2  2     4  2  4  3     2  2  2  2  3  2  2  2  3  3  3  4  3  2   |             
      Centrilobular, Atrophy               |                                           3           3           3      |             
      Serosa, Fibrosis, Focal              |                                                                   2      |             
      Sinusoid, Dilatation                 |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                  +        +              +               |             
      Fat, Inflammation, Chronic           |                                           2                              |             
      Fat, Inflammation, Granulomatous     |                                                                          |             
      Fat, Mineralization                  |                                                                          |             
      Fat, Necrosis                        |                                           2                              |             
      Lymphatic, Ectasia                   |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  A  +   |             
      Atrophy                              |                                                 1                        |             
      Hyperplasia, Nodular                 |                                                                          |             
      Inflammation, Chronic                |                                     1                                    |             
      Acinus, Hyperplasia                  |                                                                          |             
      Arteriole, Inflammation, Chronic     |                                              3                           |             
      Duct, Inflammation, Chronic          |                                  1                                       |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
      Abscess                              |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  47                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Cytoplasmic Alteration               |                                                                          |             
      Duct, Hyperplasia                    |                                           1                              |             
      Duct, Inflammation, Chronic          |                               3  1     1                    1  1         |             
      Duct, Metaplasia, Squamous           |                         2     2  1                                       |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Acanthosis                           |                                                                          |             
      Edema                                |                                                                          |             
      Hyperkeratosis                       |                                                          2               |             
      Hyperplasia, Papillary               |                                                 3                        |             
      Inflammation, Chronic                |                                                 1                        |             
      Ulcer                                |          3                                                               |             
      Epithelium, Degeneration, Ballooning |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                          +           +                  |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Cardiomyopathy                       | 2  2  3        2  2  2  2           2  2  2  2  3     3  1  2  2     3   |             
      Mineralization                       |                                                                          |             
      Atrium, Thrombosis                   |                X                                                  X      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +     +  +  +  +  +  +  +   |             
      Angiectasis                          |    2                                                                     |             
      Cyst                                 |                                                                          |             
      Degeneration, Fatty, Focal           |                      2           1                                       |             
      Hyperplasia                          |                                        1                                 |             
      Vacuolization Cytoplasmic            |          2                                               2               |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hyperplasia                          | 1  1  3              2           3     2  2                    2         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |                                        1                                 |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |       2        2  2              1           2                 2         |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Pars Distalis, Cyst                  | 1  4  1                                                                  |             
      Pars Distalis, Fibrosis              |                                                                          |             
      Pars Distalis, Hyperplasia           |          1              3                          2  2                  |             
      Pars Distalis, Necrosis              |                                                                          |             
      Pars Intermedia, Cyst                |          2                                                               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  48                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Ultimobranchial Cyst                 |          2        1                                                      |             
      C-Cell, Hyperplasia                  |          2                                                               |             
      Follicular Cell, Hyperplasia         |                      2                                                   |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Degeneration, Mucoid                 |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Abscess                              |                                                       3                  |             
      Cyst                                 |                                  2           2                           |             
      Hyperplasia                          |                                              3                           |             
      Inflammation, Chronic                |    1                             1  1     1                              |             
      Inflammation, Suppurative            | 2                                   2                                2   |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          | 1     1                                                                  |             
      Inflammation, Chronic                | 1  1  1                                                        2         |             
      Inflammation, Suppurative            |                               1                 3           2  2         |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                |                      2                                                   |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Atrophy                              | 4  1  4        4     3  2        4  4  2     4  2  3  3  2  4  2     2   |             
      Interstitial Cell, Hyperplasia       |    3                             2              2        3           2   |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |          +     +     +                    +           +     +  +     +   |             
      Left Shift                           |                                                                          |             
      Neutrophilia                         |                                                                          |             
      Thrombocytopenia                     |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Myeloid Cell, Hyperplasia            |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Bronchial, Sinus, Ectasia            |                                                                          |             
      Inguinal, Hyperplasia, Plasma Cell   |                4                                                         |             
      Inguinal, Sinus, Ectasia             |                                                                          |             
      Mediastinal, Hyperplasia, Macrophage |                2                                                         |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                                                          |             
      Mediastinal, Sinus, Ectasia          |                2                                                         |             
      Pancreatic, Hyperplasia, Macrophage  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  49                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Pancreatic, Sinus, Ectasia           |                                                                          |             
      Renal, Sinus, Ectasia                |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  M  +  +  +  +  +  +   |             
      Congestion                           |                               3                                          |             
      Hyperplasia, Plasma Cell             |    2                                                                     |             
      Sinus, Ectasia                       |                2        2        2        4                 2            |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Congestion                           |                                                                          |             
      Hyperplasia, Macrophage              |                                                          3               |             
      Hyperplasia, Plasma Cell             |                                                    3     3               |             
      Pigmentation, Hemosiderin            |                                                                          |             
      Sinus, Ectasia                       |    2              2  3                                         4         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Fibrosis                             |          2                       2                                       |             
      Hematopoietic Cell Proliferation     |                                  3                                3      |             
      Hemorrhage                           |                                                             4            |             
      Hyperplasia, Macrophage              |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +     +  +  M  +     +  +  +  +  +  +  M  +  +  +  +  M  +  +   |             
      Cyst                                 |                                                                          |             
      Epithelial Cell, Hyperplasia         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  M     +  +  +  +     M  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Hyperplasia                          |    1                                            2                    3   |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                |                                  2                                       |             
      Inflammation, Proliferative          |                                                                          |             
      Ulcer                                |                                                                          |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         |                                                             3            |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |          +                                                               |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Compression                          |    X                                            X                        |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |          +                                               +  +        +   |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  50                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 5| 4| 7| 7| 7| 7| 4| 2| 7| 7| 7| 6| 7| 7| 6| 6| 4| 7| 7| 6| 5| 4|             
                             DAY ON TEST   | 3| 3| 3| 6| 5| 3| 3| 3| 3| 5| 7| 3| 3| 3| 4| 3| 3| 7| 3| 8| 3| 3| 6| 6| 5|             
                                           | 1| 1| 1| 7| 9| 2| 2| 2| 1| 9| 3| 2| 1| 1| 6| 2| 0| 6| 7| 3| 2| 1| 5| 0| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Congestion                           |                               4                                          |             
      Hyperplasia, Macrophage              |                3                                            2  3     3   |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Inflammation, Acute                  |                                                                          |             
      Inflammation, Granulomatous          |                                                                          |             
      Necrosis, Coagulative                |                                                                          |             
      Bronchiole, Foreign Body             |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                  1                             4         |             
      Pleura, Inflammation, Chronic        |                                     1  2                                 |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Inflammation, Chronic                | 2                       2                                                |             
      Inflammation, Suppurative            |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 2     1        2  2     2        1              2  2        2  1  1      |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     | 2                                                                        |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 3  1  3        2  2  2  2        2  1  2  2  1  2  2        2  1  2      |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +  +     +  +     +  +  +  +  +  +  +  +  +  +  +   |             
      Exudate                              |                                                                          |             
      Inflammation, Chronic                | 1                                      1                                 |             
      Glands, Cyst                         |                                        1                                 |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |          +                                                               |             
      Middle Ear, Inflammation, Suppurative|                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |          +                                                           +   |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |          +                                                               |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +   |             
      Infarct                              |                                                                      2   |             
      Inflammation, Chronic                | 1  2  2        2  2  2  2        2  2  2     2     2                     |             
      Mineralization                       |                1                                                         |             
      Necrosis, Coagulative                |                                                                          |             
      Nephropathy                          | 3  4  4  3     4  3  3  3     1  3  2  3  2  4  4  2  2  2  3  3  2  2   |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |    1                             1                                       |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |       1                                                                  |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  M  +   |             
      Inflammation, Chronic                |    1                                                        1            |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  51                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +        +  +  +  A  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +        +  +  +  A  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  A  +  +  +        +  +  +  A     +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  M        +  +  +  A     +  +  +  +  A  +  +  +      |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Basophilic Focus                     |       1                             1  2                                 |             
      Clear Cell Focus                     |                                                    1                     |             
      Concretion                           |    3                                                                     |             
      Cytomegaly                           |                                                 1                        |             
      Degeneration, Cystic                 |          1     2  2              1     3        2  2        3  3         |             
      Eosinophilic Focus                   |                   3                                                      |             
      Fatty Change                         |             2                                         2                  |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hepatodiaphragmatic Nodule           |          X                                                  X            |             
      Hyperplasia, Focal                   |                3                                                         |             
      Inflammation, Chronic                |    3  2           1  1        1     1        1  1                 1      |             
      Mixed Cell Focus                     |                                              2              3            |             
      Necrosis, Coagulative                |                                        3  4                              |             
      Bile Duct, Dilatation                |    2                                                                     |             
      Bile Duct, Hyperplasia               | 3  2  3  4  2  3  4  2        2  3  2  3     3  2  2  3  1  4  4  2      |             
      Centrilobular, Atrophy               |                                                                          |             
      Serosa, Fibrosis, Focal              |                                                                          |             
      Sinusoid, Dilatation                 |                   1                             1                        |             
                                            __________________________________________________________________________|             
   Mesentery                               | +        +                                +                              |             
      Fat, Inflammation, Chronic           |          2                                                               |             
      Fat, Inflammation, Granulomatous     |                                                                          |             
      Fat, Mineralization                  |          2                                                               |             
      Fat, Necrosis                        | 2                                                                        |             
      Lymphatic, Ectasia                   |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Atrophy                              |    1  2                                         1           2            |             
      Hyperplasia, Nodular                 |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
      Acinus, Hyperplasia                  |                                                 2                        |             
      Arteriole, Inflammation, Chronic     |                                                                          |             
      Duct, Inflammation, Chronic          |                                                                          |             
                                            __________________________________________________________________________|             
   Pharynx                                 |                                                                          |             
      Abscess                              |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  52                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Cytoplasmic Alteration               |                   1                                                      |             
      Duct, Hyperplasia                    |                                                                          |             
      Duct, Inflammation, Chronic          |          1                                      1  1        1            |             
      Duct, Metaplasia, Squamous           |          2        2                          1  1                        |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Acanthosis                           |             3                                   1                        |             
      Edema                                |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia, Papillary               |                2                                   3                     |             
      Inflammation, Chronic                |             2  2                                   1                     |             
      Ulcer                                |                                                                          |             
      Epithelium, Degeneration, Ballooning |             3                                                            |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +        +  +  +  +     +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Tongue                                  |                      +                                +                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |          +                                               +     +         |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cardiomyopathy                       |       2  2  3  3  3  2        2  1  3  2  2  3  2  2  2  2  2     2      |             
      Mineralization                       |                                                                          |             
      Atrium, Thrombosis                   |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Angiectasis                          |                                                                          |             
      Cyst                                 |                                                             2            |             
      Degeneration, Fatty, Focal           |    2              2  2                                                   |             
      Hyperplasia                          |             2     2  2        2              2              2            |             
      Vacuolization Cytoplasmic            |                                           3                              |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hematopoietic Cell Proliferation     |                                                                   2      |             
      Hyperplasia                          |       2        2                 2  3     2  3                 1  2      |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  A  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |                                                 1              1         |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |    3  3        2                 2                                       |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Pars Distalis, Cyst                  |                1  3           2                                          |             
      Pars Distalis, Fibrosis              |                                                                          |             
      Pars Distalis, Hyperplasia           |       3        1              2              3           2               |             
      Pars Distalis, Necrosis              |                                                                          |             
      Pars Intermedia, Cyst                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  53                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Ultimobranchial Cyst                 |                                                                          |             
      C-Cell, Hyperplasia                  |                                  3                                       |             
      Follicular Cell, Hyperplasia         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Degeneration, Mucoid                 |       2                                                                  |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | M  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Abscess                              |                                                                          |             
      Cyst                                 |             2                                         3     2            |             
      Hyperplasia                          |                                           2                              |             
      Inflammation, Chronic                |                1  1              1                       2               |             
      Inflammation, Suppurative            |                               2                                          |             
                                            __________________________________________________________________________|             
   Prostate                                | +  M  +  +  +  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                                        2           2                     |             
      Inflammation, Suppurative            |                2                    3              2                     |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  M  +  +  +  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Atrophy                              |       3        2  2  4           4  4  3  1  4  4  3        4  2  3      |             
      Interstitial Cell, Hyperplasia       |          4                                      2                        |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +  +  +  +     +                          +              +  +  +         |             
      Left Shift                           |    X                                                                     |             
      Neutrophilia                         |    X                                      X                              |             
      Thrombocytopenia                     |                                           X                              |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Myeloid Cell, Hyperplasia            |    3                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Bronchial, Sinus, Ectasia            |    2                                                                     |             
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |             
      Inguinal, Sinus, Ectasia             |                                                                   2      |             
      Mediastinal, Hyperplasia, Macrophage |       3                                                                  |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                                       3                  |             
      Mediastinal, Sinus, Ectasia          |                                                                          |             
      Pancreatic, Hyperplasia, Macrophage  |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  54                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Pancreatic, Sinus, Ectasia           |                   3                                                      |             
      Renal, Sinus, Ectasia                |    2                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +     +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Congestion                           |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Sinus, Ectasia                       |                                  2                                       |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +     +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Congestion                           |                                                                          |             
      Hyperplasia, Macrophage              |                      3                                                   |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Pigmentation, Hemosiderin            |                                                    1                     |             
      Sinus, Ectasia                       |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Fibrosis                             |                                                             2     2      |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia, Macrophage              |                                           3                              |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  M  M  +  +  M  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Cyst                                 |                2                                                         |             
      Epithelial Cell, Hyperplasia         |                                                                   3      |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  M  +  +  +  M        +  +  +  +  +  +  +  +  +  +  +  M  +      |             
      Hyperplasia                          |    1  1     3  2              1                    2        4            |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Chronic                |                                                                   3      |             
      Inflammation, Proliferative          |                                           3                              |             
      Ulcer                                |                                                                   3      |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         |       3                                                                  |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                     +     +                              |             
      Inflammation, Chronic                |                                     1                                    |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Compression                          |             X                                                            |             
                                            __________________________________________________________________________|             
   Spinal Cord                             | +                                               +        +     +         |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  55                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 3| 7| 7| 7| 6| 7| 7| 5| 4| 4| 7| 7| 7| 7| 6| 7| 7| 7| 5| 3| 7| 6| 6| 4| 4|             
                             DAY ON TEST   | 6| 3| 3| 3| 0| 3| 3| 9| 5| 5| 3| 3| 2| 1| 0| 3| 3| 1| 9| 8| 3| 8| 1| 5| 5|             
                                           | 7| 2| 1| 1| 2| 1| 1| 6| 9| 9| 1| 1| 9| 5| 2| 2| 2| 3| 3| 1| 1| 3| 6| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
    VEHICLE                                | 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0|             
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Congestion                           |                                                                          |             
      Hyperplasia, Macrophage              |    3     4                                                  2            |             
      Hyperplasia, Adenomatous             |                      2        4  2                                       |             
      Inflammation, Acute                  |                                                       3                  |             
      Inflammation, Granulomatous          |                                                                          |             
      Necrosis, Coagulative                |                                                       3                  |             
      Bronchiole, Foreign Body             |                                                       2                  |             
      Interstitium, Inflammation, Chronic  |                2                                            2            |             
      Pleura, Inflammation, Chronic        |                                                    1                     |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Chronic                |                2                                                  1      |             
      Inflammation, Suppurative            |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         |       2  1     1     2        1  1  2                 2        1         |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |             3                                                            |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         |    2  3  1  3  2  2  2        3  2  3  1     2  2  1  2     2  2  3      |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +     +  +      |             
      Exudate                              |                                                       X                  |             
      Inflammation, Chronic                |                                                                          |             
      Glands, Cyst                         |    3              1                                      1               |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
      Middle Ear, Inflammation, Suppurative|                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                      +                                            +      |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +        +  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Infarct                              |                                                                          |             
      Inflammation, Chronic                |    2  2        2     2        2     2  2     3  2     2     2     2      |             
      Mineralization                       |                                                                          |             
      Necrosis, Coagulative                | 4                                                                        |             
      Nephropathy                          |    3  3  4  3  3  4  2        4  3  3  3  3  4  2  3  3     3  3  2      |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |    2                                                                     |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  M  +  +  A  +  +  +        M  +  +  +  +  +  +  +  +  +  +  +  +      |             
      Inflammation, Chronic                |                1                    1  1           1              1      |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  56                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  A  +  +     +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  A  +  +     +  +  +  +                                 |  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  A  +  +     +  +  +  +                                 |  51        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  A  +  +     +  +  +  +                                 |  53        |
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  A  +  +     +  +  +  +                                 |  52        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  A  +  +     +  +  +  +                                 |  52        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  A  A  +     +  +  +  +                                 |  48        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  M  A  +     +  +  +  +                                 |  44        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Basophilic Focus                     |                2     2                                                   |     11  1.5|
      Clear Cell Focus                     |                                                                          |      1  1.0|
      Concretion                           |                                                                          |      1  3.0|
      Cytomegaly                           |                                                                          |      2  1.5|
      Degeneration, Cystic                 |    2  1        2  2  2  2     2                                          |     26  2.0|
      Eosinophilic Focus                   |                                                                          |      4  2.0|
      Fatty Change                         | 1                                                                        |      5  1.8|
      Hematopoietic Cell Proliferation     |                                                                          |      2  1.5|
      Hepatodiaphragmatic Nodule           |                                  X                                       |      6     |
      Hyperplasia, Focal                   |                                                                          |      1  3.0|
      Inflammation, Chronic                | 1                             1                                          |     18  1.4|
      Mixed Cell Focus                     |          2     3                                                         |      6  2.5|
      Necrosis, Coagulative                |                         2                                                |      7  2.6|
      Bile Duct, Dilatation                |                                                                          |      1  2.0|
      Bile Duct, Hyperplasia               | 2  3  2  3     3  3  2  3     3  2  2  2                                 |     54  2.6|
      Centrilobular, Atrophy               |    3                    3                                                |      5  3.0|
      Serosa, Fibrosis, Focal              |                                                                          |      1  2.0|
      Sinusoid, Dilatation                 |                                                                          |      2  1.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               | +  +                    +     +     +  +                                 |  12        |
      Fat, Inflammation, Chronic           |    2                          2                                          |      4  2.0|
      Fat, Inflammation, Granulomatous     | 3                                                                        |      1  3.0|
      Fat, Mineralization                  |                                                                          |      1  2.0|
      Fat, Necrosis                        |    2                                                                     |      3  2.0|
      Lymphatic, Ectasia                   | 3                                                                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Atrophy                              |    2                                                                     |      6  1.5|
      Hyperplasia, Nodular                 |          3                                                               |      1  3.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Acinus, Hyperplasia                  |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  57                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Arteriole, Inflammation, Chronic     |                                                                          |      1  3.0|
      Duct, Inflammation, Chronic          |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Pharynx                                 |          +                                                               |   1        |
      Abscess                              |          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Cytoplasmic Alteration               |                                     2                                    |      2  1.5|
      Duct, Hyperplasia                    |                                                                          |      1  1.0|
      Duct, Inflammation, Chronic          |                1     2  1     2  1  2                                    |     15  1.3|
      Duct, Metaplasia, Squamous           |                1     2  2     2     2                                    |     12  1.7|
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Acanthosis                           |                                     2                                    |      3  2.0|
      Edema                                |                                     2                                    |      1  2.0|
      Hyperkeratosis                       |                                     2                                    |      2  2.0|
      Hyperplasia, Papillary               |                                                                          |      3  2.7|
      Inflammation, Chronic                |                                                                          |      4  1.5|
      Ulcer                                |                                                                          |      1  3.0|
      Epithelium, Degeneration, Ballooning |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |    +                                +                                    |   8        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Cardiomyopathy                       | 2  1  2        1  1  1  1     3  1  1  2                                 |     46  2.0|
      Mineralization                       |                   2                                                      |      1  2.0|
      Atrium, Thrombosis                   |                                        X                                 |      4     |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Angiectasis                          |                                                                          |      1  2.0|
      Cyst                                 |                                                                          |      1  2.0|
      Degeneration, Fatty, Focal           |                3                                                         |      6  2.0|
      Hyperplasia                          |                                                                          |      7  1.9|
      Vacuolization Cytoplasmic            |    2                                2                                    |      5  2.2|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  2.0|
      Hyperplasia                          |                   3  2  2                                                |     19  2.1|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  58                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Hyperplasia                          |                                                                          |      3  1.0|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  M  +                                 |  54        |
      Hyperplasia                          |    2           2              3                                          |     13  2.2|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Pars Distalis, Cyst                  |                   2                                                      |      7  2.0|
      Pars Distalis, Fibrosis              |       2                                                                  |      1  2.0|
      Pars Distalis, Hyperplasia           |                   2  2              1                                    |     12  2.0|
      Pars Distalis, Necrosis              |                                  3                                       |      1  3.0|
      Pars Intermedia, Cyst                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Ultimobranchial Cyst                 |                                                                          |      2  1.5|
      C-Cell, Hyperplasia                  |                         4           2                                    |      4  2.8|
      Follicular Cell, Hyperplasia         |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  M  +     +  +  +  +     +  +  +  +                                 |  53        |
      Degeneration, Mucoid                 |                                                                          |      1  2.0|
      Inflammation, Chronic                |    1                                                                     |      1  1.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Abscess                              |                                                                          |      1  3.0|
      Cyst                                 |                                                                          |      5  2.2|
      Hyperplasia                          |                                                                          |      2  2.5|
      Inflammation, Chronic                |       1  2        1                    2                                 |     12  1.3|
      Inflammation, Suppurative            |    2                                                                     |      5  2.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Hyperplasia                          |          2                                                               |      3  1.3|
      Inflammation, Chronic                |                   2                                                      |      7  1.6|
      Inflammation, Suppurative            |                                  2     3                                 |      9  2.2|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Inflammation, Chronic                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Atrophy                              | 4  3  4  4     4     2  3     4                                          |     39  3.1|
      Interstitial Cell, Hyperplasia       |    3              4              1     1                                 |     11  2.5|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  59                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |    +              +     +        +  +                                    |  22        |
      Left Shift                           |                                                                          |      1     |
      Neutrophilia                         |                                                                          |      2     |
      Thrombocytopenia                     |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Myeloid Cell, Hyperplasia            |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Bronchial, Sinus, Ectasia            |                                                                          |      1  2.0|
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |      1  4.0|
      Inguinal, Sinus, Ectasia             |                                                                          |      1  2.0|
      Mediastinal, Hyperplasia, Macrophage |                                                                          |      2  2.5|
      Mediastinal, Pigmentation,           |                                                                          |            |
          Hemosiderin                      |                                                                          |      1  3.0|
      Mediastinal, Sinus, Ectasia          |                                                                          |      1  2.0|
      Pancreatic, Hyperplasia, Macrophage  | 2                                                                        |      1  2.0|
      Pancreatic, Sinus, Ectasia           | 2                                                                        |      2  2.5|
      Renal, Sinus, Ectasia                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +                                    |  52        |
      Congestion                           |                                                                          |      1  3.0|
      Hyperplasia, Plasma Cell             |                                  3                                       |      2  2.5|
      Sinus, Ectasia                       | 4                                                                        |      7  2.6|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Congestion                           |                                  3                                       |      1  3.0|
      Hyperplasia, Macrophage              |                                                                          |      2  3.0|
      Hyperplasia, Plasma Cell             |                                  3                                       |      3  3.0|
      Pigmentation, Hemosiderin            |                                                                          |      1  1.0|
      Sinus, Ectasia                       | 3     3  2     3              2                                          |      9  2.7|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Fibrosis                             |                2  2     4                                                |      7  2.3|
      Hematopoietic Cell Proliferation     |                                        3                                 |      3  3.0|
      Hemorrhage                           |                                                                          |      1  4.0|
      Hyperplasia, Macrophage              |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +     M  +  +  +                                 |  46        |
      Cyst                                 |                                                                          |      1  2.0|
      Epithelial Cell, Hyperplasia         |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  49        |
      Hyperplasia                          |    3  2           1     2                                                |     14  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  60                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                |          2                    3                                          |      4  2.5|
      Inflammation, Proliferative          |                                                                          |      1  3.0|
      Ulcer                                |                                                                          |      1  3.0|
      Subcutaneous Tissue, Inflammation,   |                                                                          |            |
           Chronic                         |                                                                          |      2  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                     +                                    |   4        |
      Inflammation, Chronic                |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Compression                          |       X                                                                  |      4     |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |    +           +  +              +  +  M                                 |  13        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  |          +                                                               |   1        |
      Inflammation, Chronic                |          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Congestion                           |          3                                                               |      2  3.5|
      Hyperplasia, Macrophage              |                                                                          |      7  2.9|
      Hyperplasia, Adenomatous             |                                                                          |      3  2.7|
      Inflammation, Acute                  |                                                                          |      1  3.0|
      Inflammation, Granulomatous          |                               1                                          |      1  1.0|
      Necrosis, Coagulative                |                                                                          |      1  3.0|
      Bronchiole, Foreign Body             |                                                                          |      1  2.0|
      Interstitium, Inflammation, Chronic  |                                                                          |      4  2.3|
      Pleura, Inflammation, Chronic        |                      2                                                   |      4  1.5|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                | 2              1        1     4                                          |      8  1.9|
      Inflammation, Suppurative            |                               3                                          |      1  3.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         | 1  2           2  2           1  2     1                                 |     27  1.6|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                   2                                                      |      3  2.3|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         | 3  2     2     2  2     2     1  2  1  1                                 |     45  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  61                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 6| 4| 7| 7| 7| 7| 4| 7| 5| 5| 4| 4|                             |            |
                             DAY ON TEST   | 3| 3| 8| 5| 5| 3| 3| 1| 0| 5| 3| 4| 1| 5| 5|                             |            |
                                           | 2| 2| 1| 4| 9| 1| 0| 0| 2| 9| 2| 6| 5| 9| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                             |      A     |
    VEHICLE                                | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|                             |      L     |
    CONTROL                                | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Exudate                              |                                                                          |      1     |
      Inflammation, Chronic                |          1                                                               |      3  1.0|
      Glands, Cyst                         |                                                                          |      4  1.5|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |          +                                                               |   2        |
      Middle Ear, Inflammation, Suppurative|          3                                                               |      1  3.0|
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                        +                                 |   2        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |          +                                                               |   3        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Infarct                              |                                                                          |      1  2.0|
      Inflammation, Chronic                | 2                    2        2                                          |     27  2.0|
      Mineralization                       |                                                                          |      1  1.0|
      Necrosis, Coagulative                |                                                                          |      1  4.0|
      Nephropathy                          | 4  4  3  3     4  2  2  2     3  3  3  1                                 |     53  2.9|
      Renal Tubule, Inflammation,          |                                                                          |            |
          Suppurative                      |                               1                                          |      4  1.3|
      Transitional Epithelium, Hyperplasia,|                                                                          |            |
           Papillary                       |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  51        |
      Inflammation, Chronic                |                                                                          |      7  1.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  62                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Ulcer                                |                3                                                         |             
      Venule, Thrombosis                   |                X                                                         |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Serosa, Inflammation, Chronic        |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  M  +  +     +  +  +     M     +  +  +     M        +  +               |             
      Edema                                |                                                                          |             
      Hemorrhage                           |          1                                                               |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +     +  +  +           +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Basophilic Focus                     |                                  2                 1        1     1      |             
      Clear Cell Focus                     |                      3                             2                     |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Cystic                 | 1              1                    1           2  1  2     2  2  2      |             
      Eosinophilic Focus                   |                                                                          |             
      Fatty Change                         |                                  3                       1               |             
      Focal Cellular Change                |                                                 2                        |             
      Hematocyst                           |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                   1      |             
      Hepatodiaphragmatic Nodule           |                                                          X               |             
      Hyperplasia, Multifocal              |                                                                          |             
      Inflammation, Chronic                |    1  2           1           2                 1  1              1      |             
      Mixed Cell Focus                     |                                                                   2      |             
      Necrosis, Coagulative                |          2           2                                                   |             
      Bile Duct, Hyperplasia               | 3  3  2  3     3  4        2  4  3  3  1        1  3  3  3  2  4  2      |             
      Centrilobular, Atrophy               |                                  2  3                                    |             
      Serosa, Inflammation, Chronic        |                                                                          |             
      Sinusoid, Dilatation                 |                                                 2           2     1      |             
      Vein, Dilatation                     |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                +  +                 +              +                     |             
      Accessory Spleen                     |                   X                                X                     |             
      Fat, Inflammation, Chronic           |                                                                          |             
      Fat, Necrosis                        |                                     2                                    |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Atrophy                              | 2        1                                            2                  |             
      Hyperplasia, Nodular                 |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Cytoplasmic Alteration               | 1                                                                        |             
      Hyperplasia                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  63                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Duct, Inflammation, Chronic          | 1                                                                        |             
      Duct, Metaplasia, Squamous           | 1                                                                        |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Abscess                              |                                     1                                    |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia, Papillary               |                                                                          |             
      Inflammation, Chronic                |    1                                                                     |             
      Ulcer, Chronic                       |                                                                          |             
      Ulcer                                |                3                                                         |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Erosion                              |                                                                          |             
      Inflammation, Acute                  |                                                                          |             
      Inflammation, Chronic                |                   1                                                      |             
      Ulcer                                |                                  2                                       |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                 +  +                                    |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Cardiomyopathy                       | 2  3  2  2     2  2  2           2     2     1        2  3               |             
      Thrombosis                           |                                                                          |             
      Atrium, Thrombosis                   |                                  X                    X                  |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +     +      |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Degeneration, Fatty, Focal           | 1                                                     1                  |             
      Hyperplasia                          | 1                                                                        |             
      Necrosis, Coagulative                |                                                                          |             
      Vacuolization Cytoplasmic            |                2                                                         |             
      Capsule, Hyperplasia                 |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +     +      |             
      Atrophy                              |                                                                          |             
      Fibrosis                             |                                                                          |             
      Hyperplasia                          |                3     2           1              2  2  2                  |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Hyperplasia                          |                                                                          |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +     +  +  +     +     +  +  +     +        +  +  M            |             
      Hyperplasia                          | 2                                                                        |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Pars Distalis, Cyst                  |    2                                3                          1         |             
      Pars Distalis, Hemorrhage            |                                     2                                    |             
      Pars Distalis, Hyperplasia           |    3  2  3           1        2  2                 2  3  2               |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  64                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Pars Distalis, Necrosis              |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      C-Cell, Hyperplasia                  | 2                 2                    2              1                  |             
      Follicle, Cyst                       |                            3                                             |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +     +  +  +     M  +  +  +  +     M        +  +               |             
      Abscess                              | 2                                                                        |             
      Cyst                                 |                      4                 4                                 |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |    1  1  2        1           2  1     2                 2               |             
      Inflammation, Suppurative            |                                        2                                 |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +     +  +  +     +     +  +  +     +  +     +  +               |             
      Abscess                              |                                                                          |             
      Hemorrhage                           | 2                                                                        |             
      Hyperplasia, Focal                   |                                                 2                        |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                                     2                                    |             
      Inflammation, Suppurative            |                1  2              2                    2                  |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Atrophy                              | 3              2              3     2           3  4  2     4  3  4      |             
      Cyst                                 |                                                                          |             
      Bilateral, Interstitial Cell,        |                                                                          |             
          Hyperplasia                      |                                                          2               |             
      Interstitial Cell, Hyperplasia       |                3              3                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +        +     +  +        +  +  +  +  +              +     +            |             
      Anemia                               |                                        X                                 |             
      Hypersegmentation                    | X                                                                        |             
      Neutrophilia                         | X                                      X                                 |             
      Thrombocytopenia                     |                                        X                                 |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Depletion Cellular                   |                                                                          |             
      Myelofibrosis                        |                                                                          |             
      Myeloid Cell, Hyperplasia            | 3                                      3                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  65                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +     +  +  +  +  +     +        +  +               |             
      Bronchial, Pigmentation, Hemosiderin |                                                                          |             
      Bronchial, Sinus, Ectasia            |                                                                          |             
      Iliac, Sinus, Ectasia                |                                        4                                 |             
      Inguinal, Hyperplasia, Plasma Cell   |       2                                                                  |             
      Lumbar, Hyperplasia, Macrophage      |                                                                          |             
      Lumbar, Hyperplasia, Plasma Cell     |                                                                          |             
      Lumbar, Pigmentation, Hemosiderin    |                      3                                                   |             
      Lumbar, Sinus, Ectasia               |                               2  2                                       |             
      Mediastinal, Hyperplasia, Macrophage |                                                                          |             
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |             
      Mediastinal, Sinus, Ectasia          | 1                                      3                                 |             
      Pancreatic, Sinus, Ectasia           | 2                                                                        |             
      Renal, Sinus, Ectasia                |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +     +  M  +     +  +  +  +  +     +        +  +               |             
      Hyperplasia, Lymphoid                |                                                                          |             
      Hyperplasia, Plasma Cell             | 3        4                                                               |             
      Sinus, Ectasia                       | 4                             3                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +     +  +  +  +  +     +        +  +               |             
      Depletion Lymphoid                   |                                                                          |             
      Hyperplasia, Macrophage              | 3                                                                        |             
      Sinus, Ectasia                       |                                  2     3                                 |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +     +  +  +  +  +      |             
      Fibrosis                             | 4                                                                        |             
      Hematopoietic Cell Proliferation     | 3                    4                 3                                 |             
      Capsule, Infarct                     |                                  2                                       |             
      Capsule, Inflammation, Chronic       |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  +     +  +  +     +  M  +  +  +     +        +  M               |             
      Cyst                                 |                                                                          |             
      Inflammation                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  M  +        +  +  +     +     +  +  +     M        +  M               |             
      Hyperplasia                          |                                  2                    1                  |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +     +  +  +     +     +  +  +     +  +     +  +               |             
      Cyst Epithelial Inclusion            |                                                                          |             
      Inflammation, Chronic                |                                        3                                 |             
      Inflammation, Granulomatous          |                                                                          |             
      Ulcer                                |                      2                                                   |             
      Hindlimb, Subcutaneous Tissue, Right,|                                                                          |             
           Inflammation, Acute             |       4                                                                  |             
      Hindlimb, Right, Epidermis, Abscess, |                                                                          |             
           Multiple                        |       3                                                                  |             
      Hindlimb, Right, Epidermis,          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  66                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
          Degeneration, Ballooning         |       4                                                                  |             
      Sebaceous Gland, Hyperplasia         |                                                       3                  |             
      Subcutaneous Tissue, Cyst            |                                                                          |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         | 3                                                                        |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Inflammation, Chronic Active         |       4                                                                  |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         | +                    +                                                   |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Compression                          |                                                                          |             
      Cerebellum, Embolus Tumor            |                                                                          |             
      Cerebellum, Infarct                  |                                                                          |             
      Choroid Plexus, Inflammation, Chronic|                                                                          |             
      Ventricle, Dilatation                |                                                                          |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                      +                                                   |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                +           +     +     +     +           +               |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Congestion                           |                                                                          |             
      Hemorrhage                           |                      2                                                   |             
      Hyperplasia, Macrophage              |          3                                                               |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Arteriole, Media, Hyperplasia        |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                  1                                       |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Inflammation, Chronic                |                2                                                         |             
      Metaplasia, Squamous                 |    1                                                                     |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         |          1           2     2     1                    3  1               |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     | 2  1                                                                     |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 2     1  2           3     2     1                    3  2               |             
      Respiratory Epithelium, Cyst         |                1                                                         |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  67                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 5| 5| 4| 6| 6| 6| 4| 2| 7| 6| 5| 5| 4| 0| 7| 7| 6| 4| 7| 7| 7| 4| 4|             
                             DAY ON TEST   | 1| 5| 8| 4| 5| 2| 1| 1| 5| 6| 3| 3| 9| 3| 5| 8| 3| 3| 8| 3| 3| 3| 3| 5| 5|             
                                           | 8| 1| 3| 0| 9| 5| 7| 0| 9| 3| 2| 2| 9| 6| 9| 6| 2| 1| 9| 1| 2| 2| 1| 9| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 8| 8| 8| 8| 8|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Exudate                              |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                   +                                            +         |             
      Hemorrhage                           |                                                                3         |             
      Synechia                             |                   3                                                      |             
      Cornea, Proliferation                |                   2                                                      |             
      Retina, Atrophy                      |                   2                                            4         |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                   +                                                      |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          | +                                                                        |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +     +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +      |             
      Cyst                                 |                               2                                          |             
      Infarct                              |                3                                                         |             
      Inflammation, Chronic                | 2  2  3              2        2  2              3  2        2  2  2      |             
      Nephropathy                          | 4  3  3  3     2  4  3        3  3  3  2        4  3  3  2  3  3  3      |             
      Pelvis, Hematopoietic Cell           |                                                                          |             
          Proliferation                    | 2                                                                        |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                                                    2           1         |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                   2      |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +     +  +  +     +     +  +  +     +        +  +               |             
      Hyperplasia, Papillary               |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  68                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  A  A        +  +           +        +  +  +  +     +     +  A  +|             
      Ulcer                                |                                                                          |             
      Venule, Thrombosis                   |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  A        +  +           +        +  +     +     +     +  +  +|             
      Serosa, Inflammation, Chronic        |          3                                                               |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  M  +        +  +           +        +  +     +     +     +  +  +|             
      Edema                                |                                                                          |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  A  A        +  +           +        +  +     +     +     +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  A  A        +  +           +        +  A  +  +     +     +  A  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Basophilic Focus                     |                2        1     1              1  1                        |             
      Clear Cell Focus                     |                   X           1                    3                     |             
      Cytomegaly                           |                                                                          |             
      Degeneration, Cystic                 | 2              1        1     1  1           1     2  1              1   |             
      Eosinophilic Focus                   |                      2                                                   |             
      Fatty Change                         |                                                                          |             
      Focal Cellular Change                |                                                                          |             
      Hematocyst                           |                                                    X                     |             
      Hematopoietic Cell Proliferation     |                                                             1            |             
      Hepatodiaphragmatic Nodule           |                                     X           X              X        X|             
      Hyperplasia, Multifocal              |                                                                          |             
      Inflammation, Chronic                | 2              1  1     1     1  1                             2     1   |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis, Coagulative                |    2                                                                     |             
      Bile Duct, Hyperplasia               | 3  4  4  2  3  1  3  3  2     2  2  3        2  2  3  3     2  3  3  3  3|             
      Centrilobular, Atrophy               |    3              1                                   2                 2|             
      Serosa, Inflammation, Chronic        |                                                                   1      |             
      Sinusoid, Dilatation                 |                      2                          1                        |             
      Vein, Dilatation                     |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               | +  +     +              +     +                 +  +        +     +     +|             
      Accessory Spleen                     |                               X                                          |             
      Fat, Inflammation, Chronic           |          4                                      2                        |             
      Fat, Necrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Atrophy                              |    2                                                              3      |             
      Hyperplasia, Nodular                 |                                                                   2      |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Cytoplasmic Alteration               |                                                                          |             
      Hyperplasia                          |                         2                                                |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  69                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Duct, Inflammation, Chronic          |                         2                                         1      |             
      Duct, Metaplasia, Squamous           |                         2                                                |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Abscess                              |                                                                          |             
      Hemorrhage                           |             2                                                            |             
      Hyperplasia, Papillary               |                                                                         2|             
      Inflammation, Chronic                |                                                                          |             
      Ulcer, Chronic                       |                                                                          |             
      Ulcer                                |             2                       3                                    |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  A  +        +  +           +        +  +     +           +  +  +|             
      Erosion                              |                                                                          |             
      Inflammation, Acute                  |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |    +                                                  +           +     +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Cardiomyopathy                       |          2  3        2  2           1        2  2                 2  2  1|             
      Thrombosis                           |                                                    X                     |             
      Atrium, Thrombosis                   |                                              X                    X      |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +  +  +     +  +  +     +     +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +  +           +  +           +        +  +  +  +     +     +  +  +|             
      Degeneration, Fatty, Focal           |                                                 2                        |             
      Hyperplasia                          |                                                 1                    1   |             
      Necrosis, Coagulative                |                                                                         2|             
      Vacuolization Cytoplasmic            | 1  1  2                                               2                  |             
      Capsule, Hyperplasia                 |                                                       1                  |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +  +  M     +  +  +     +     +        +  +  +  +     +     +  +  +|             
      Atrophy                              |                                                                          |             
      Fibrosis                             |                                                                          |             
      Hyperplasia                          | 2                 1  2        3              1     2  1              2   |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  A  +        +  +           +        +  +  +  +     +     +  +  +|             
      Hyperplasia                          |                      3                                2                  |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +        +  +           +        +  +  +  +     M     +  +  +|             
      Hyperplasia                          |                                                    2                    2|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                  1              2              1  2      |             
      Pars Distalis, Hemorrhage            |                                                                          |             
      Pars Distalis, Hyperplasia           |                2     1                          2                       2|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  70                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Pars Distalis, Necrosis              |       4                                                                  |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +     +  +  +           +        +  +  +  +     +     +  +  +|             
      C-Cell, Hyperplasia                  |    3                                                                     |             
      Follicle, Cyst                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                              +                           |             
      Inflammation, Suppurative            |                                              4                           |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Penis                                   |                                                                   +      |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  M  +  +     +  +  +           +        +  +  M  +     M     +  +  +|             
      Abscess                              |                                                                          |             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |          2                                                               |             
      Inflammation, Chronic                |                      1                       1                           |             
      Inflammation, Suppurative            |    1                                                                     |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +           +        +  +  +  +     +     +  +  +|             
      Abscess                              |                                              4                           |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia, Focal                   |                                                                          |             
      Hyperplasia                          |                2  3                                                      |             
      Inflammation, Chronic                |                                                                          |             
      Inflammation, Suppurative            |       2                                         2                        |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +        +  +           +        +  +  M  +     +     +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Atrophy                              | 4  4        3  4  4  3        4  3  4              4           4  4     2|             
      Cyst                                 |                                                                          |             
      Bilateral, Interstitial Cell,        |                                                                          |             
          Hyperplasia                      |                                                                          |             
      Interstitial Cell, Hyperplasia       |       3                             1                       2           2|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |    +  +              +                       +     +  +     +     +     +|             
      Anemia                               |                                                             X            |             
      Hypersegmentation                    |                                                                          |             
      Neutrophilia                         |                                              X                           |             
      Thrombocytopenia                     |                                                             X            |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Depletion Cellular                   |                                                                          |             
      Myelofibrosis                        |                                                       3                  |             
      Myeloid Cell, Hyperplasia            |                                              2                           |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  71                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +  +        +  +           +        +  +  +  +     +  +  +  +  +|             
      Bronchial, Pigmentation, Hemosiderin |                                                    3                     |             
      Bronchial, Sinus, Ectasia            |                                                    3                     |             
      Iliac, Sinus, Ectasia                |                                                                          |             
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |             
      Lumbar, Hyperplasia, Macrophage      |                         2                                                |             
      Lumbar, Hyperplasia, Plasma Cell     |                         4                                                |             
      Lumbar, Pigmentation, Hemosiderin    |                                                                          |             
      Lumbar, Sinus, Ectasia               |                                                                          |             
      Mediastinal, Hyperplasia, Macrophage |                                                       3                  |             
      Mediastinal, Hyperplasia, Plasma Cell|                                                       3                  |             
      Mediastinal, Sinus, Ectasia          |                                                                          |             
      Pancreatic, Sinus, Ectasia           |                                                                          |             
      Renal, Sinus, Ectasia                |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Hyperplasia, Lymphoid                |             2                                                            |             
      Hyperplasia, Plasma Cell             |                         4                             3                  |             
      Sinus, Ectasia                       |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +        +  +           +        +  +  +        +  +  +  +  +|             
      Depletion Lymphoid                   |                                                    2                     |             
      Hyperplasia, Macrophage              | 3        3                                                               |             
      Sinus, Ectasia                       |                                                 2              4         |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  A  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Fibrosis                             |                               2                                         2|             
      Hematopoietic Cell Proliferation     |                                              2              3            |             
      Capsule, Infarct                     |                                                                          |             
      Capsule, Inflammation, Chronic       |                                                                   1      |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +        +  +     +     +        +  +  M  +     +     +  +  +|             
      Cyst                                 |                                                                          |             
      Inflammation                         |                               3                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  M  M  +        +  +           +        +  +  +  +     +     +  +  +|             
      Hyperplasia                          | 2  1                    2                    1                           |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  M  +        +  +           +        +  +  +  +     +     +  +  +|             
      Cyst Epithelial Inclusion            |                      1                                                   |             
      Inflammation, Chronic                |                                              2                           |             
      Inflammation, Granulomatous          | 3                                                                        |             
      Ulcer                                | 3                    3  3                             3                 4|             
      Hindlimb, Subcutaneous Tissue, Right,|                                                                          |             
           Inflammation, Acute             |                                                                          |             
      Hindlimb, Right, Epidermis, Abscess, |                                                                          |             
           Multiple                        |                                                                          |             
      Hindlimb, Right, Epidermis,          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  72                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
          Degeneration, Ballooning         |                                                                          |             
      Sebaceous Gland, Hyperplasia         |                                                                          |             
      Subcutaneous Tissue, Cyst            |                                                       2                  |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Chronic                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                         +                                                |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Compression                          |                         X           X                                    |             
      Cerebellum, Embolus Tumor            |                                                                          |             
      Cerebellum, Infarct                  |                                                                          |             
      Choroid Plexus, Inflammation, Chronic|                                                                      1   |             
      Ventricle, Dilatation                |                                     3                                    |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |       +     +                                      +        +            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Congestion                           |                                                                      4   |             
      Hemorrhage                           |                                                                          |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Adenomatous             |                      2                                                   |             
      Arteriole, Media, Hyperplasia        |                      2                                                   |             
      Interstitium, Inflammation, Chronic  |                                                             3            |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Inflammation, Chronic                | 1                       3                    2        2                  |             
      Metaplasia, Squamous                 |                                                                          |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         |    1  2  2  2           2                    2  3  1  1              2   |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                          |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         |    1  2  2  2           2                    2  3  1  2              2  1|             
      Respiratory Epithelium, Cyst         |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Inflammation, Chronic                |                                                                      1   |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                              +        +                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  73                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 5| 4| 4| 7| 7| 6| 6| 4| 7| 7| 6| 4| 4| 7| 6| 6| 6| 4| 3| 7| 7| 7| 6|             
                             DAY ON TEST   | 2| 0| 7| 9| 6| 3| 3| 6| 5| 5| 3| 3| 3| 5| 5| 2| 6| 5| 5| 5| 9| 3| 1| 0| 5|             
                                           | 3| 9| 6| 0| 6| 1| 1| 2| 5| 9| 2| 1| 8| 9| 9| 8| 8| 6| 3| 9| 2| 1| 3| 3| 9|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    25 MG/KG                               | 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
      Exudate                              |                                              X                           |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                 +                        |             
      Hemorrhage                           |                                                                          |             
      Synechia                             |                                                 3                        |             
      Cornea, Proliferation                |                                                                          |             
      Retina, Atrophy                      |                                                 4                        |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                 +                        |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                   +                          +        +                  |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +     +  +  +        +  +  +  +     +  +  +  +  +|             
      Cyst                                 |                               1                                          |             
      Infarct                              |                                                                          |             
      Inflammation, Chronic                | 1              1  2     2     2  2           2  2     2        2     2   |             
      Nephropathy                          | 4  4  4  1  3  2  3  2  3     3  3  2        3  2  3  2     2  3  2  3  3|             
      Pelvis, Hematopoietic Cell           |                                                                          |             
          Proliferation                    |                                                                          |             
      Renal Tubule, Inflammation,          |                                                                          |             
          Suppurative                      |                   1              1                             1         |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |    1                          2  1                                       |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +        +  +           +        +  +  +  +     +     +  +  +|             
      Hyperplasia, Papillary               |                                              4                           |             
      Inflammation, Chronic                |                                              2                           |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  74                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +        +           +  +        +  +                                 |  37        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +        +           +  +        +  +                                 |  37        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +        +           +  +        +  +                                 |  34        |
      Ulcer                                |                                                                          |      1  3.0|
      Venule, Thrombosis                   |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +        +           +  +        +  +                                 |  35        |
      Serosa, Inflammation, Chronic        |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +        +           +  +        +  +                                 |  32        |
      Edema                                |                                     3                                    |      1  3.0|
      Hemorrhage                           |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +        +           +  +        +  +                                 |  35        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +        +           +  +        +  +                                 |  33        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | M  M        +           +  +        +  +                                 |  30        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Basophilic Focus                     |                   3  4                                                   |     11  1.6|
      Clear Cell Focus                     |          4           2                                                   |      7  2.5|
      Cytomegaly                           |                                     3                                    |      1  3.0|
      Degeneration, Cystic                 |       2           3  2  2        2                                       |     23  1.6|
      Eosinophilic Focus                   |                                     2                                    |      2  2.0|
      Fatty Change                         |                         2              3                                 |      4  2.3|
      Focal Cellular Change                |                                                                          |      1  2.0|
      Hematocyst                           |                                                                          |      1     |
      Hematopoietic Cell Proliferation     |    2                                                                     |      3  1.3|
      Hepatodiaphragmatic Nodule           |             X        X  X  X           X                                 |     10     |
      Hyperplasia, Multifocal              |                                     3                                    |      1  3.0|
      Inflammation, Chronic                |    2  2        1  2                                                      |     19  1.4|
      Mixed Cell Focus                     |                      2                                                   |      2  2.0|
      Necrosis, Coagulative                | 4                                                                        |      4  2.5|
      Bile Duct, Hyperplasia               |    3  2  3  4  2  3  2  2  3  2  2  4  3                                 |     52  2.7|
      Centrilobular, Atrophy               | 4                                   3                                    |      8  2.5|
      Serosa, Inflammation, Chronic        |                                                                          |      1  1.0|
      Sinusoid, Dilatation                 |          1           1                                                   |      7  1.4|
      Vein, Dilatation                     | 3                                                                        |      1  3.0|
                                            __________________________________________________________________________|____________|
   Mesentery                               |                   +                    +                                 |  16        |
      Accessory Spleen                     |                                                                          |      3     |
      Fat, Inflammation, Chronic           |                                        2                                 |      3  2.7|
      Fat, Necrosis                        |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +        +           +  +        +  +                                 |  36        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  75                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Atrophy                              |                         2                                                |      6  2.0|
      Hyperplasia, Nodular                 |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +        +           +  +        +  +                                 |  37        |
      Cytoplasmic Alteration               |                                                                          |      1  1.0|
      Hyperplasia                          |                                                                          |      1  2.0|
      Duct, Inflammation, Chronic          |                                                                          |      3  1.3|
      Duct, Metaplasia, Squamous           |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +        +           +  +        +  +                                 |  36        |
      Abscess                              |                                                                          |      1  1.0|
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia, Papillary               |                                     2                                    |      2  2.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Ulcer, Chronic                       |                                        4                                 |      1  4.0|
      Ulcer                                |                                                                          |      3  2.7|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +        +           +  +        +  +                                 |  34        |
      Erosion                              |                                     1                                    |      1  1.0|
      Inflammation, Acute                  |                                     1                                    |      1  1.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Ulcer                                |                                                                          |      1  2.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |             +           +                                                |   9        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +        +           +  +  +     +  +                                 |  38        |
      Cardiomyopathy                       |    3        1           2  2        2  2                                 |     28  2.0|
      Thrombosis                           |                                                                          |      1     |
      Atrium, Thrombosis                   |                               X                                          |      5     |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +  +  +  +     +  +  +     +  +                                 |  49        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +                 +  +  +     +  +                                 |  37        |
      Degeneration, Fatty, Focal           |                                     1                                    |      4  1.3|
      Hyperplasia                          |                         1                                                |      4  1.0|
      Necrosis, Coagulative                |                                                                          |      1  2.0|
      Vacuolization Cytoplasmic            |                                     1  2                                 |      7  1.6|
      Capsule, Hyperplasia                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +  +  +  +     +  +  +     +  +                                 |  48        |
      Atrophy                              |             4                                                            |      1  4.0|
      Fibrosis                             |             3                                                            |      1  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  76                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia                          |    1     2     3  2           1                                          |     19  1.8|
      Mineralization                       |             1                                                            |      1  1.0|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +        +           +  +        +  +                                 |  36        |
      Hyperplasia                          |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +        +           +  +        +  +                                 |  36        |
      Hyperplasia                          |             4           2              2                                 |      6  2.3|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  M  +  +  +                                 |  54        |
      Pars Distalis, Cyst                  |    1                                                                     |      8  1.6|
      Pars Distalis, Hemorrhage            |                                                                          |      1  2.0|
      Pars Distalis, Hyperplasia           |                   2                                                      |     14  2.1|
      Pars Distalis, Necrosis              |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +        +           +  +        +  +                                 |  38        |
      C-Cell, Hyperplasia                  |                                                                          |      5  2.0|
      Follicle, Cyst                       |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                          |   1        |
      Inflammation, Suppurative            |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +        +           +  +        +  +                                 |  37        |
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | M  +        +  +        +  +        +  +                                 |  34        |
      Abscess                              |                                                                          |      1  2.0|
      Cyst                                 |                                                                          |      2  4.0|
      Hyperplasia                          |                                                                          |      1  2.0|
      Inflammation, Chronic                |    1        1              1                                             |     13  1.3|
      Inflammation, Suppurative            |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +        +           +  +  +     +  +                                 |  41        |
      Abscess                              |                                                                          |      1  4.0|
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia, Focal                   |                                                                          |      1  2.0|
      Hyperplasia                          |                               2        1                                 |      4  2.0|
      Inflammation, Chronic                |                                                                          |      1  2.0|
      Inflammation, Suppurative            | 2                          3                                             |      8  2.0|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +        +           +  +        +  +                                 |  36        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +     +  +  +  +  +  +  +  +  +  +                                 |  54        |
      Atrophy                              |       4        4  4  4  4     3  4  3                                    |     31  3.5|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  77                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Cyst                                 |                   3                                                      |      1  3.0|
      Bilateral, Interstitial Cell,        |                                                                          |            |
          Hyperplasia                      |                                                                          |      1  2.0|
      Interstitial Cell, Hyperplasia       |    3                                                                     |      7  2.4|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   |             +           +  +  +     +                                    |  25        |
      Anemia                               |                                                                          |      2     |
      Hypersegmentation                    |                                                                          |      1     |
      Neutrophilia                         |                                                                          |      3     |
      Thrombocytopenia                     |                                                                          |      2     |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +        +           +  +        +  +                                 |  37        |
      Depletion Cellular                   |                                     3                                    |      1  3.0|
      Myelofibrosis                        |                                     2                                    |      2  2.5|
      Myeloid Cell, Hyperplasia            |                                                                          |      3  2.7|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +     +           +  +  +     +  +                                 |  41        |
      Bronchial, Pigmentation, Hemosiderin |                                                                          |      1  3.0|
      Bronchial, Sinus, Ectasia            |                                                                          |      1  3.0|
      Iliac, Sinus, Ectasia                |                                                                          |      1  4.0|
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |      1  2.0|
      Lumbar, Hyperplasia, Macrophage      |                                                                          |      1  2.0|
      Lumbar, Hyperplasia, Plasma Cell     |                                                                          |      1  4.0|
      Lumbar, Pigmentation, Hemosiderin    |                                                                          |      1  3.0|
      Lumbar, Sinus, Ectasia               |                                                                          |      2  2.0|
      Mediastinal, Hyperplasia, Macrophage |                                                                          |      1  3.0|
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |      1  3.0|
      Mediastinal, Sinus, Ectasia          |                                                                          |      2  2.0|
      Pancreatic, Sinus, Ectasia           |                                                                          |      1  2.0|
      Renal, Sinus, Ectasia                |       3                                                                  |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +        +           +  +  +     +  +                                 |  38        |
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|
      Hyperplasia, Plasma Cell             |                                                                          |      4  3.5|
      Sinus, Ectasia                       |                               3                                          |      3  3.3|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +        +           +  +        +  +                                 |  38        |
      Depletion Lymphoid                   |                                     3                                    |      2  2.5|
      Hyperplasia, Macrophage              |                                                                          |      3  3.0|
      Sinus, Ectasia                       |             3                                                            |      5  2.8|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +     +  +  +  +  +  +  +  +  +  +  +                                 |  52        |
      Fibrosis                             |                               4     3                                    |      5  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  78                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hematopoietic Cell Proliferation     |                                                                          |      5  3.0|
      Capsule, Infarct                     |                                                                          |      1  2.0|
      Capsule, Inflammation, Chronic       |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M     +  M  M     +  +  +  M  +  +                                 |  35        |
      Cyst                                 |             2                                                            |      1  2.0|
      Inflammation                         |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M        +           +  +        +  +                                 |  29        |
      Hyperplasia                          |                         2              2                                 |      8  1.6|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +        +           +  +        +  +                                 |  37        |
      Cyst Epithelial Inclusion            |                                                                          |      1  1.0|
      Inflammation, Chronic                |                                                                          |      2  2.5|
      Inflammation, Granulomatous          |                                                                          |      1  3.0|
      Ulcer                                |                                                                          |      6  3.0|
      Hindlimb, Subcutaneous Tissue, Right,|                                                                          |            |
           Inflammation, Acute             |                                                                          |      1  4.0|
      Hindlimb, Right, Epidermis, Abscess, |                                                                          |            |
           Multiple                        |                                                                          |      1  3.0|
      Hindlimb, Right, Epidermis,          |                                                                          |            |
          Degeneration, Ballooning         |                                                                          |      1  4.0|
      Sebaceous Gland, Hyperplasia         |                                                                          |      1  3.0|
      Subcutaneous Tissue, Cyst            |                                                                          |      1  2.0|
      Subcutaneous Tissue, Inflammation,   |                                                                          |            |
           Chronic                         |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +        +           +  +        +  +                                 |  37        |
      Inflammation, Chronic Active         |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   3        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +        +           +  +        +  +                                 |  37        |
      Compression                          |                                                                          |      2     |
      Cerebellum, Embolus Tumor            |                            X                                             |      1     |
      Cerebellum, Infarct                  |                            3                                             |      1  3.0|
      Choroid Plexus, Inflammation, Chronic|                                                                          |      1  1.0|
      Ventricle, Dilatation                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   1        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  79                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 NERVOUS SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             | +  +                    +                                                |  13        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +     +           +  +        +  +                                 |  38        |
      Congestion                           |                                                                          |      1  4.0|
      Hemorrhage                           |                                                                          |      1  2.0|
      Hyperplasia, Macrophage              |             2                                                            |      2  2.5|
      Hyperplasia, Adenomatous             |       3                                                                  |      2  2.5|
      Arteriole, Media, Hyperplasia        |                                                                          |      1  2.0|
      Interstitium, Inflammation, Chronic  |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +        +           +  +        +  +                                 |  37        |
      Inflammation, Chronic                |             1                       3                                    |      7  2.0|
      Metaplasia, Squamous                 |                                                                          |      1  1.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         |    2        1           1  1        2                                    |     21  1.7|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                                                                          |      2  1.5|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         |    2        2           2  1        2                                    |     24  1.9|
      Respiratory Epithelium, Cyst         |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +        +           +  +        +  +                                 |  37        |
      Inflammation, Chronic                |                                                                          |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   2        |
      Exudate                              |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   3        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Synechia                             |                                                                          |      2  3.0|
      Cornea, Proliferation                |                                                                          |      1  2.0|
      Retina, Atrophy                      |                                                                          |      3  3.3|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                                                                          |   4        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +                                 |  55        |
      Cyst                                 |                                                                          |      2  1.5|
      Infarct                              |                                                                          |      1  3.0|
      Inflammation, Chronic                |       2  2     2  2  1     2        2  2                                 |     30  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  80                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 2| 4| 7| 7| 6| 7| 7| 7| 7| 6| 7| 7| 7| 6| 4|                             |            |
                             DAY ON TEST   | 0| 2| 3| 3| 8| 3| 3| 3| 2| 1| 3| 3| 2| 7| 5|                             |            |
                                           | 7| 9| 1| 1| 6| 2| 2| 2| 8| 2| 2| 1| 8| 3| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|                             |      A     |
    25 MG/KG                               | 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Nephropathy                          |    3  3  4  3  3  3  2  3  3  3  2  3  4                                 |     52  2.9|
      Pelvis, Hematopoietic Cell           |                                                                          |            |
          Proliferation                    |                                                                          |      1  2.0|
      Renal Tubule, Inflammation,          |                                                                          |            |
          Suppurative                      |       1        1                                                         |      7  1.1|
      Transitional Epithelium, Hyperplasia,|                                                                          |            |
           Papillary                       |                2              2                                          |      6  1.7|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +        +           +  +        +  +                                 |  37        |
      Hyperplasia, Papillary               |                                                                          |      1  4.0|
      Inflammation, Chronic                |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  81                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +        +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +           +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +        +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                         2                                                |             
      Muscularis, Inflammation, Chronic    |    2                                                                     |             
      Muscularis, Mineralization           |    2                                         3                           |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +           M  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
      Muscularis, Mineralization           |                                              1                           |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Capillary, Degeneration, Hyaline     |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Muscularis, Inflammation, Chronic    |    1                                                                     |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +           +  +  +  +  +  +  +  A  +  +     +  +  +  +  +  +  +  +  +  +|             
      Capillary, Degeneration, Hyaline     |                                                                          |             
      Muscularis, Inflammation, Chronic    |                                              3                           |             
      Muscularis, Mineralization           |                                              3                           |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +           +  +  +  +  +  +  +  A  +  +     +  M  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                               2              1                           |             
      Clear Cell Focus                     |                                              2                           |             
      Cytomegaly                           |                      2                                                   |             
      Degeneration, Cystic                 | 1  1           1  1                          1     2        1  3     1  1|             
      Eosinophilic Focus                   |                                              2                           |             
      Fatty Change                         |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Hepatodiaphragmatic Nodule           | X                    X                             X                 X   |             
      Hyperplasia, Focal                   |                            2                                             |             
      Hyperplasia, Multifocal              |                                                                          |             
      Inflammation, Chronic                |                                     1  1     1  1     1     1     1  1   |             
      Necrosis, Coagulative                |                      2     2           1     1        3                  |             
      Necrosis, Coagulative, Multifocal    |                                                                          |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    |                                        1              4                  |             
      Arteriole, Thrombosis                |                                        X              X                  |             
      Bile Duct, Hyperplasia               | 2  2           2  4  4  2  3  2  3  4  4     2  3  2  3  2  2  4  2  2  3|             
      Centrilobular, Atrophy               |                      2                 2           2                     |             
      Sinusoid, Dilatation                 |                                              3                           |             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +           +                 +     +         |             
      Fat, Necrosis                        |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                      1                                                   |             
      Duct, Inflammation, Chronic          |                                                                          |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  82                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Atrophy, Focal                       |                                  2                                       |             
      Duct, Inflammation, Chronic          |                                                          2  1            |             
      Duct, Metaplasia, Squamous           |                               1                                          |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia, Papillary               |                                                                          |             
      Inflammation, Chronic                |                                                                          |             
      Ulcer                                |                                                                          |             
      Muscularis, Mineralization           | 4  4                    4                    2                           |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic                | 2                                                                        |             
      Mineralization                       | 3  4                    3                    4                           |             
      Ulcer                                |                                                       3                  |             
                                            __________________________________________________________________________|             
   Tooth                                   |                   +                                      +     +         |             
      Pulp, Proliferation Connective       |                                                                          |             
          Tissue, Focal                    |                   2                                                      |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Cardiomyopathy                       | 3  2           3  2  2  3  1  1  3  2  2     3  2  2  1     2  2  2  1  2|             
      Mineralization                       | 3  4                    3        3           3                           |             
      Atrium, Dilatation                   |                                                                          |             
      Atrium, Thrombosis                   |    3                                                           X         |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Angiectasis                          |                                                                          |             
      Degeneration, Fatty, Focal           |    2                                               3        1            |             
      Hyperplasia                          |    2                                               3        1            |             
      Vacuolization Cytoplasmic            |                            1                                             |             
      Capsule, Hyperplasia                 |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    2           2  2  1  2  1        2        2                          1|             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  M  +  +  +  +  +  +|             
      Cyst                                 |                                                          2               |             
      Hyperplasia                          | 4  4           4        4        4  3        4              2            |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +        +  +  +  +  M  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                               2                                          |             
      Pars Distalis, Hyperplasia           |                               2                                   2     2|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  83                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Ultimobranchial Cyst                 |                                                                          |             
      C-Cell, Hyperplasia                  |                                                       1  2              4|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                        +                                 |             
      Inflammation, Chronic                |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Degeneration, Mucoid                 |                                                                          |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +        M  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Abscess                              |    2                                                                     |             
      Cyst                                 |                   1  4        2                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                1                    2                 2  2        2  1   |             
      Inflammation, Suppurative            |                                                                          |             
      Necrosis, Coagulative                |                                                                          |             
      Pigmentation, Hemosiderin            |                                                       2                  |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Abscess                              |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Inflammation, Chronic                |                                  2                       2        3      |             
      Inflammation, Suppurative            |                2  3     2  3                          2        2  4      |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                              3                           |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              | 3  4           3     2  1     4  4  3        4  4           4  2     3  3|             
      Cyst                                 |                                                                          |             
      Interstitial Cell, Hyperplasia       |                                     3              2  2                  |             
      Seminiferous Tubule, Degeneration,   |                                                                          |             
           Cystic                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   |                   +  +     +        +  +           +  +  +     +  +      |             
      Neutrophilia                         |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Myelofibrosis                        | 2                                            2                           |             
      Erythroid Cell, Hyperplasia          |    2                                                                     |             
      Myeloid Cell, Hyperplasia            |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Cortex, Mediastinal, Atrophy         |                                                                          |             
      Iliac, Hyperplasia, Plasma Cell      |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  84                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Iliac, Sinus, Ectasia                |                                                                          |             
      Inguinal, Hyperplasia, Lymphoid      |                                                                          |             
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |             
      Inguinal, Sinus, Ectasia             |                                                                          |             
      Lumbar, Hyperplasia, Plasma Cell     |                                                                          |             
      Mediastinal, Hyperplasia, Macrophage |                                                                          |             
      Mediastinal, Hyperplasia, Plasma Cell|                                                    2                     |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                                                          |             
      Mediastinal, Sinus, Ectasia          |                                              4                           |             
      Renal, Pigmentation, Hemosiderin     |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Plasma Cell             |                                                                      3   |             
      Sinus, Ectasia                       |    2                                                                     |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Depletion Lymphoid                   | 2                                                                        |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Sinus, Ectasia                       |                                              3                           |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Fibrosis                             |                   2                                         1            |             
      Hematopoietic Cell Proliferation     |    3                                                                     |             
      Hyperplasia, Macrophage              |                                                                          |             
      Red Pulp, Depletion Cellular         | 3                                                                        |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Congestion                           |             3                                                            |             
      Cyst                                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +        +  +  +  +  +  +  +  +  +  +     M  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |                                                                          |             
      Mineralization                       |                         1                                                |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +        +  +  +  +  +  +  +  +  +  +     M  +  +  +  +  +  +  +  +  +|             
      Abscess                              |                                                                          |             
      Inflammation, Chronic                |                               4                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Ulcer                                |                                                                          |             
      Scrotal, Inflammation, Suppurative   |                                                                          |             
      Subcutaneous Tissue, Abscess         |                                                                          |             
      Subcutaneous Tissue, Edema           |                                                                          |             
      Subcutaneous Tissue, Hemorrhage      |                                                                          |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Suppurative                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  85                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Fibrous Osteodystrophy               |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                         +                                +               |             
      Degeneration                         |                                                                          |             
      Mineralization                       |                         3                                                |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Compression                          |                   X                                                      |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                          +               |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                 +                        |             
      Hemorrhage                           |                                                 4                        |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Atelectasis                          |                                                                          |             
      Crystals                             |                                                          2               |             
      Hemorrhage                           |                                                    1     2               |             
      Hyperplasia, Macrophage              |                         1                    2           2     2         |             
      Hyperplasia, Adenomatous             |                                                             3            |             
      Inflammation, Suppurative            |                                                 2                        |             
      Mineralization                       |                         1                    1                           |             
      Necrosis, Liquifactive               |                                                                          |             
      Proliferation Connective Tissue      |                                                                          |             
      Arteriole, Thrombosis                |                                                                          |             
      Interstitium, Fibrosis               |                                                                2         |             
      Interstitium, Inflammation, Chronic  |                                                                2         |             
      Pleura, Inflammation, Chronic        | 2                                                                        |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic                |                         2           2                          3         |             
      Inflammation, Suppurative            |                                                                3         |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 2              3     2     1  2  2     2     2  2           2  3     3  2|             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                 1                        |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 2  3           3  2  3  2  2  3  2     2     3  2        2  3  3  3  3  3|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic                |                                                          2               |             
      Glands, Cyst                         |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  86                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 6| 4| 4| 3| 6| 6| 6| 6| 5| 7| 7| 6| 6| 4| 7| 6| 6| 5| 5| 7| 7| 7| 7| 6|             
                             DAY ON TEST   | 1| 7| 5| 5| 1| 8| 8| 7| 3| 2| 3| 2| 1| 0| 5| 0| 8| 1| 6| 5| 3| 3| 3| 0| 4|             
                                           | 8| 2| 9| 9| 8| 9| 6| 2| 1| 2| 1| 0| 2| 6| 9| 0| 2| 2| 2| 4| 2| 1| 1| 7| 8|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                               +     +                                    |             
      Cornea, Inflammation, Subacute       |                                                                          |             
      Cornea, Necrosis                     |                                                                          |             
      Retina, Atrophy                      |                               4                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                  +                                       |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 2  3                    2                                                |             
      Hemorrhage                           |                                                          2               |             
      Inflammation, Chronic                | 1  2           2  2     2     2  1  2        2  2                    2   |             
      Nephropathy                          | 4  4        2  4  3  3  4  3  4  4  4  3     4  3  2  3  4  4  4  4  3  2|             
      Pelvis, Inflammation, Suppurative    |                   2                                                      |             
      Renal Tubule, Hyperplasia, Focal     |                2                                                         |             
      Renal Tubule, Hyperplasia            |                                                                          |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +        +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic                |                                                          1               |             
      Inflammation, Chronic Active         |                   3                                                      |             
      Submucosa, Edema                     |                                        2                                 |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  87                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +        +  +  +  +     +  A  +  +  A  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +        +  +  +  +     +  +  +  +  A  +  +  +  +     +  +  +  +  +|             
      Mineralization                       |                                                                          |             
      Muscularis, Inflammation, Chronic    |                                                                          |             
      Muscularis, Mineralization           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Muscularis, Mineralization           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Capillary, Degeneration, Hyaline     |                                     3                                    |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Muscularis, Inflammation, Chronic    |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +        +  +  +  +     +  +     +  A  +  +  A  +     +  +  +  +  +|             
      Capillary, Degeneration, Hyaline     |       2                                                                  |             
      Muscularis, Inflammation, Chronic    |                                                                          |             
      Muscularis, Mineralization           |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +        +  +  +  +     +  A  +  +  A  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Basophilic Focus                     | 1                    1  2                    1                           |             
      Clear Cell Focus                     |    1           2                                                         |             
      Cytomegaly                           |                   2                                                  3   |             
      Degeneration, Cystic                 | 3  2              2                 2           1                        |             
      Eosinophilic Focus                   |                                                                          |             
      Fatty Change                         |                1                       3                                1|             
      Hematopoietic Cell Proliferation     |                               1                                          |             
      Hepatodiaphragmatic Nodule           |       X                             X        X     X  X                  |             
      Hyperplasia, Focal                   |                                                                          |             
      Hyperplasia, Multifocal              |                                                                      4   |             
      Inflammation, Chronic                |                               1     2     1  1                    1      |             
      Necrosis, Coagulative                |                   2                                3                     |             
      Necrosis, Coagulative, Multifocal    |                                                                          |             
      Arteriole, Inflammation,             |                                                                          |             
          Proliferative                    |                                                                          |             
      Arteriole, Thrombosis                |                                                                          |             
      Bile Duct, Hyperplasia               | 3  3  3        2  4  3  2     3  3  3  3  2  3  4  3  2     2  3  3  3  2|             
      Centrilobular, Atrophy               |       1                          2                                   2  3|             
      Sinusoid, Dilatation                 | 2  2                 2                                                   |             
                                            __________________________________________________________________________|             
   Mesentery                               | +                 +                 +                                   +|             
      Fat, Necrosis                        |                                     2                                   3|             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Atrophy                              |                                           1  2                          3|             
      Duct, Inflammation, Chronic          |                                              1                           |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  88                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Atrophy, Focal                       |                                                                          |             
      Duct, Inflammation, Chronic          |                                                                   1      |             
      Duct, Metaplasia, Squamous           |                1  2  1  1     1                                          |             
                                            __________________________________________________________________________|             
   Stomach                                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Acanthosis                           |                                                                          |             
      Hyperkeratosis                       |                                                                          |             
      Hyperplasia, Papillary               |                   2                                                      |             
      Inflammation, Chronic                |                                                                          |             
      Ulcer                                |                                                                          |             
      Muscularis, Mineralization           |                                                                          |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Inflammation, Chronic                |                                                                          |             
      Mineralization                       |                                                                          |             
      Ulcer                                |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   | +                 +  +  +                             +     +            |             
      Pulp, Proliferation Connective       |                                                                          |             
          Tissue, Focal                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Cardiomyopathy                       | 1  2  2        1  2  2  2     3  2  2  3  2     2  1        2  2  3      |             
      Mineralization                       |                                                                          |             
      Atrium, Dilatation                   |                                                                          |             
      Atrium, Thrombosis                   |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Gland, Cortex                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Accessory Adrenal Cortical Nodule    |                                           X                              |             
      Angiectasis                          |                                                       2                  |             
      Degeneration, Fatty, Focal           |       2                                            2  2                  |             
      Hyperplasia                          |       2           1                    2     2              1        1   |             
      Vacuolization Cytoplasmic            |       1                                                                 2|             
      Capsule, Hyperplasia                 |                                     1                                    |             
                                            __________________________________________________________________________|             
   Adrenal Gland, Medulla                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Hyperplasia                          |                               2              1  1     3     1  1         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +        +  +  M  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |       3                 4                       3           3  3         |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Pars Distalis, Cyst                  |                         2                       2           2            |             
      Pars Distalis, Hyperplasia           |                         2                       2     1                  |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  89                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Ultimobranchial Cyst                 |                                                             2            |             
      C-Cell, Hyperplasia                  | 1                       1                    1                           |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                   +      |             
      Inflammation, Chronic                |                                                                   1      |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Degeneration, Mucoid                 |                3     1                                                   |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Abscess                              |                                                                          |             
      Cyst                                 |    3                                2  2              3                  |             
      Hyperplasia                          |                                                                   3      |             
      Inflammation, Chronic                |    3  1              1  1     3              1     1                     |             
      Inflammation, Suppurative            |                                        1                                 |             
      Necrosis, Coagulative                |                                  3                                       |             
      Pigmentation, Hemosiderin            |                                                    2                     |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Abscess                              |                                                                         2|             
      Hyperplasia                          |                   1  1           1           1                           |             
      Inflammation, Chronic                |                      1                                                   |             
      Inflammation, Suppurative            |                                     2                                1   |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Atrophy                              |    4  3           4  3  4     4                 2  4        4  3  4  2  3|             
      Cyst                                 |                                                       2                  |             
      Interstitial Cell, Hyperplasia       |                                                                         2|             
      Seminiferous Tubule, Degeneration,   |                                                                          |             
           Cystic                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood                                   | +  +  +           +  +  +     +        +     +  +  +        +  +     +  +|             
      Neutrophilia                         |                                                                         X|             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Myelofibrosis                        |                   2                                                      |             
      Erythroid Cell, Hyperplasia          |                               3                                          |             
      Myeloid Cell, Hyperplasia            |                               3                                         3|             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Cortex, Mediastinal, Atrophy         |                                                                          |             
      Iliac, Hyperplasia, Plasma Cell      |                                                                         3|             
 _____________________________________________________________________________________________________________________|             
                                                             Page  90                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Iliac, Sinus, Ectasia                |                                                                         3|             
      Inguinal, Hyperplasia, Lymphoid      |                                                                          |             
      Inguinal, Hyperplasia, Plasma Cell   |                                                                         4|             
      Inguinal, Sinus, Ectasia             |                                                                          |             
      Lumbar, Hyperplasia, Plasma Cell     |                                                                         3|             
      Mediastinal, Hyperplasia, Macrophage |                                     2                                    |             
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |             
      Mediastinal, Pigmentation,           |                                                                          |             
          Hemosiderin                      |                                     2                                    |             
      Mediastinal, Sinus, Ectasia          |                                     2                                    |             
      Renal, Pigmentation, Hemosiderin     |                   3                                                      |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +        +  +  +  +     +  +  +  +  +     +  +  +     +  +  +  +  +|             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Sinus, Ectasia                       |       4                                                                  |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +        +  +  +  +     +  +  +  +  +     +  +  +     +  +  +  +  +|             
      Depletion Lymphoid                   |                                                                          |             
      Hyperplasia, Macrophage              |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                         3|             
      Sinus, Ectasia                       |                                           2                              |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Fibrosis                             |    1  4                                         2           3  3     3   |             
      Hematopoietic Cell Proliferation     |                               3                                         3|             
      Hyperplasia, Macrophage              |                                                    1                     |             
      Red Pulp, Depletion Cellular         |                                                                          |             
                                            __________________________________________________________________________|             
   Thymus                                  | M  M  +        M  +  M  M     +  +  M  +  +  +  +  M  +     +  +  +  +  +|             
      Congestion                           |                                                                          |             
      Cyst                                 |                               2                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +        +  +  +  +     +  +  +  +  +  +  +  M  +     +  +  +  +  +|             
      Cyst                                 |                                                                          |             
      Hyperplasia                          |                               2                 2                        |             
      Mineralization                       |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Abscess                              |                                                                         3|             
      Inflammation, Chronic                |                               3           2                             3|             
      Inflammation, Suppurative            |                                                                          |             
      Ulcer                                |                                                                         2|             
      Scrotal, Inflammation, Suppurative   |                                                                         3|             
      Subcutaneous Tissue, Abscess         |                                                                          |             
      Subcutaneous Tissue, Edema           |                                                                         4|             
      Subcutaneous Tissue, Hemorrhage      |                                  3                                       |             
      Subcutaneous Tissue, Inflammation,   |                                                                          |             
           Suppurative                     |                                  3                                       |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  91                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Fibrous Osteodystrophy               |                                                                          |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |       +                                   +                       +      |             
      Degeneration                         |                                                                   2      |             
      Mineralization                       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Compression                          |                                                                          |             
                                            __________________________________________________________________________|             
   Spinal Cord                             | +                    +  +              +                    +           +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Larynx                                  |                                                                          |             
      Hemorrhage                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Atelectasis                          |                                           2                              |             
      Crystals                             |                                                                          |             
      Hemorrhage                           |                                           2                              |             
      Hyperplasia, Macrophage              |       1                 2                                                |             
      Hyperplasia, Adenomatous             |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Mineralization                       |                                                                          |             
      Necrosis, Liquifactive               |                                           2                              |             
      Proliferation Connective Tissue      |                                           3                              |             
      Arteriole, Thrombosis                |                               X                                          |             
      Interstitium, Fibrosis               |                                                                          |             
      Interstitium, Inflammation, Chronic  |                                                                          |             
      Pleura, Inflammation, Chronic        |                                           1                              |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Inflammation, Chronic                |                                                                2  2      |             
      Inflammation, Suppurative            |                                           3                              |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Chronic                         | 2     2        1  2  2                 2  1     2           2     3  2   |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                          |             
      Nasolacrimal Duct, Metaplasia,       |                                                                          |             
          Squamous                         | 2  3  2        3  2  3        2  2  2  2  1  3  3  2        2     3  3   |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Inflammation, Chronic                |                                                                          |             
      Glands, Cyst                         |    2                                                                     |             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  92                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 6| 4| 4| 7| 7| 7| 7| 4| 7| 7| 7| 6| 6| 7| 7| 5| 5| 4| 7| 7| 7| 6| 5|             
                             DAY ON TEST   | 3| 3| 6| 5| 5| 3| 3| 3| 3| 5| 3| 1| 0| 3| 0| 3| 1| 9| 8| 5| 3| 3| 3| 5| 0|             
                                           | 2| 1| 9| 9| 9| 2| 2| 2| 2| 9| 1| 0| 0| 7| 6| 1| 1| 7| 1| 9| 1| 1| 1| 9| 1|             
 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    50 MG/KG                               | 2| 2| 2| 2| 2| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6|             
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
      Cornea, Inflammation, Subacute       |                                                                          |             
      Cornea, Necrosis                     |                                                                          |             
      Retina, Atrophy                      |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                  +              +                        |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Cyst                                 | 4                                                                        |             
      Hemorrhage                           |                                                                          |             
      Inflammation, Chronic                |                2     2        2  2  2     2  2     2              2      |             
      Nephropathy                          | 4  4  4        3  4  4  4     3  3  4  3  2  4  3  3  2     4  4  4  3  1|             
      Pelvis, Inflammation, Suppurative    |                                                                          |             
      Renal Tubule, Hyperplasia, Focal     |                                                                          |             
      Renal Tubule, Hyperplasia            |                                              2                           |             
      Transitional Epithelium, Hyperplasia,|                                                                          |             
           Papillary                       |                               3              1                 3         |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +        +  +  +  +     +  +  +  +  +  +  +  +  +     +  +  +  +  +|             
      Inflammation, Chronic                |                               1                                          |             
      Inflammation, Chronic Active         |                                                                          |             
      Submucosa, Edema                     |                                                                          |             
 _____________________________________________________________________________________________________________________|             
                                                             Page  93                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Intestine Large                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +     +  +  +  +     +  +  A  +                                 |  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Mineralization                       |                                                                          |      1  2.0|
      Muscularis, Inflammation, Chronic    |                                                                          |      1  2.0|
      Muscularis, Mineralization           |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  52        |
      Muscularis, Mineralization           |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Intestine Small                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Capillary, Degeneration, Hyaline     |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Muscularis, Inflammation, Chronic    |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +     +  +  +  +     +  +  A  +                                 |  49        |
      Capillary, Degeneration, Hyaline     |                                                                          |      1  2.0|
      Muscularis, Inflammation, Chronic    |                                                                          |      1  3.0|
      Muscularis, Mineralization           |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +     +  A  +  +     +  +  A  +                                 |  48        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Basophilic Focus                     |                                                                          |      6  1.3|
      Clear Cell Focus                     |                         3                                                |      4  2.0|
      Cytomegaly                           |                                                                          |      3  2.3|
      Degeneration, Cystic                 | 2                 2                 2                                    |     18  1.6|
      Eosinophilic Focus                   |                                                                          |      1  2.0|
      Fatty Change                         |                         1                                                |      4  1.5|
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|
      Hepatodiaphragmatic Nodule           |                                                                          |      9     |
      Hyperplasia, Focal                   |                                                                          |      1  2.0|
      Hyperplasia, Multifocal              |                                                                          |      1  4.0|
      Inflammation, Chronic                |          1     2     1  1     1     1                                    |     19  1.1|
      Necrosis, Coagulative                |                                                                          |      7  2.0|
      Necrosis, Coagulative, Multifocal    |                                     3                                    |      1  3.0|
      Arteriole, Inflammation,             |                                                                          |            |
          Proliferative                    |                                     3                                    |      3  2.7|
      Arteriole, Thrombosis                |                                                                          |      2     |
      Bile Duct, Hyperplasia               | 3  3  1  3     3  2  3  2     3  1  3  1                                 |     54  2.7|
      Centrilobular, Atrophy               | 2                       2           2                                    |     10  2.0|
      Sinusoid, Dilatation                 |                                                                          |      4  2.3|
                                            __________________________________________________________________________|____________|
   Mesentery                               |    +                                                                     |   9        |
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  94                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Fat, Necrosis                        |                                                                          |      2  2.5|
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +     +  +     +     +  +  +  +                                 |  54        |
      Atrophy                              |                                     2                                    |      5  1.8|
      Duct, Inflammation, Chronic          |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Atrophy, Focal                       |                                                                          |      1  2.0|
      Duct, Inflammation, Chronic          |                1              1                                          |      5  1.2|
      Duct, Metaplasia, Squamous           |                                                                          |      6  1.2|
                                            __________________________________________________________________________|____________|
   Stomach                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Acanthosis                           |                      2           3                                       |      2  2.5|
      Hyperkeratosis                       |                      2           3                                       |      2  2.5|
      Hyperplasia, Papillary               |                                                                          |      1  2.0|
      Inflammation, Chronic                |                                  1                                       |      1  1.0|
      Ulcer                                |       3                                                                  |      1  3.0|
      Muscularis, Mineralization           |                                                                          |      4  3.5|
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                |                                                                          |      1  2.0|
      Mineralization                       |                      2                                                   |      5  3.2|
      Ulcer                                |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Tooth                                   |                      +                                                   |  10        |
      Pulp, Proliferation Connective       |                                                                          |            |
          Tissue, Focal                    |                                                                          |      1  2.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Cardiomyopathy                       |    3  1  2     3     2  4     2  1  2  2                                 |     47  2.1|
      Mineralization                       | 2                       3                                                |      7  3.0|
      Atrium, Dilatation                   | 3                                                                        |      1  3.0|
      Atrium, Thrombosis                   |    X                                                                     |      4  3.0|
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Cortex                   | +  +  +  +     +  +     +     +  +  +  +                                 |  54        |
      Accessory Adrenal Cortical Nodule    |                                                                          |      1     |
      Angiectasis                          |                                                                          |      1  2.0|
      Degeneration, Fatty, Focal           |                                                                          |      6  2.0|
      Hyperplasia                          |    2           2                                                         |     11  1.7|
      Vacuolization Cytoplasmic            |       2                 3        3     1                                 |      7  1.9|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  95                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Capsule, Hyperplasia                 |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Adrenal Gland, Medulla                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Hyperplasia                          |    2  3                 1     2  2  2  2                                 |     22  1.7|
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Cyst                                 |                                                                          |      1  2.0|
      Hyperplasia                          | 2     3        3  4  3  4                                                |     19  3.4|
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Pars Distalis, Cyst                  | 1                                4  1                                    |      7  2.0|
      Pars Distalis, Hyperplasia           |       3  3           3        2     2                                    |     11  2.2|
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Ultimobranchial Cyst                 |                                                                          |      1  2.0|
      C-Cell, Hyperplasia                  |                               2                                          |      7  1.7|
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                          |   2        |
      Inflammation, Chronic                |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Degeneration, Mucoid                 |    2                          2                                          |      4  2.0|
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Abscess                              |                                                                          |      1  2.0|
      Cyst                                 |                                                                          |      7  2.4|
      Hyperplasia                          |                                                                          |      1  3.0|
      Inflammation, Chronic                |                                                                          |     13  1.6|
      Inflammation, Suppurative            |                                                                          |      1  1.0|
      Necrosis, Coagulative                |                                                                          |      1  3.0|
      Pigmentation, Hemosiderin            |                                                                          |      2  2.0|
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Abscess                              |                                                                          |      1  2.0|
      Hyperplasia                          |                                                                          |      4  1.0|
      Inflammation, Chronic                |                                     1                                    |      5  1.8|
      Inflammation, Suppurative            |       3        2     2           2                                       |     13  2.3|
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Mineralization                       |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Atrophy                              | 3  4              3  3  3     4  3     3                                 |     35  3.3|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  96                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Cyst                                 |                                                                          |      1  2.0|
      Interstitial Cell, Hyperplasia       |                   4  3                 2                                 |      7  2.6|
      Seminiferous Tubule, Degeneration,   |                                                                          |            |
           Cystic                          | 1                                                                        |      1  1.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood                                   | +  +                                +  +                                 |  29        |
      Neutrophilia                         |                                                                          |      1     |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Myelofibrosis                        |                                                                          |      3  2.0|
      Erythroid Cell, Hyperplasia          |                                                                          |      2  2.5|
      Myeloid Cell, Hyperplasia            |    3                                                                     |      3  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Cortex, Mediastinal, Atrophy         |                                  4                                       |      1  4.0|
      Iliac, Hyperplasia, Plasma Cell      |                                                                          |      1  3.0|
      Iliac, Sinus, Ectasia                |                                                                          |      1  3.0|
      Inguinal, Hyperplasia, Lymphoid      |    4                                                                     |      1  4.0|
      Inguinal, Hyperplasia, Plasma Cell   |                                        4                                 |      2  4.0|
      Inguinal, Sinus, Ectasia             |                                        4                                 |      1  4.0|
      Lumbar, Hyperplasia, Plasma Cell     |                                                                          |      1  3.0|
      Mediastinal, Hyperplasia, Macrophage |                                                                          |      1  2.0|
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |      1  2.0|
      Mediastinal, Pigmentation,           |                                                                          |            |
          Hemosiderin                      |                                                                          |      1  2.0|
      Mediastinal, Sinus, Ectasia          | 3                                                                        |      3  3.0|
      Renal, Pigmentation, Hemosiderin     |                                                                          |      1  3.0|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Hyperplasia, Plasma Cell             |    4     2                                                               |      3  3.0|
      Sinus, Ectasia                       |          4                    3                                          |      4  3.3|
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Depletion Lymphoid                   |                                                                          |      1  2.0|
      Hyperplasia, Macrophage              |                      2                                                   |      1  2.0|
      Hyperplasia, Plasma Cell             |                                                                          |      1  3.0|
      Sinus, Ectasia                       |       2                                                                  |      3  2.3|
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Fibrosis                             |                                                                          |      8  2.4|
      Hematopoietic Cell Proliferation     |                                                                          |      3  3.0|
      Hyperplasia, Macrophage              |                                                                          |      1  1.0|
      Red Pulp, Depletion Cellular         |                                                                          |      1  3.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  97                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +     +  +  +  +     +  M  +  M                                 |  46        |
      Congestion                           |                                                                          |      1  3.0|
      Cyst                                 |    2                                                                     |      2  2.0|
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +     +  +  +  +     +  +  +  +                                 |  53        |
      Cyst                                 |                3                                                         |      1  3.0|
      Hyperplasia                          | 2     2  2     4  2  2  2        2                                       |     10  2.2|
      Mineralization                       |                                                                          |      1  1.0|
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  54        |
      Abscess                              |                                                                          |      1  3.0|
      Inflammation, Chronic                |          3                                                               |      5  3.0|
      Inflammation, Suppurative            |                                        3                                 |      1  3.0|
      Ulcer                                | 3  3                                   3                                 |      4  2.8|
      Scrotal, Inflammation, Suppurative   |                                                                          |      1  3.0|
      Subcutaneous Tissue, Abscess         |    4              4                                                      |      2  4.0|
      Subcutaneous Tissue, Edema           |                                                                          |      1  4.0|
      Subcutaneous Tissue, Hemorrhage      |                                                                          |      1  3.0|
      Subcutaneous Tissue, Inflammation,   |                                                                          |            |
           Suppurative                     |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Fibrous Osteodystrophy               |                      4                                                   |      1  4.0|
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                      +                                                   |   6        |
      Degeneration                         |                                                                          |      1  2.0|
      Mineralization                       |                                                                          |      1  3.0|
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Compression                          |                         X        X                                       |      3     |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |          +                          +                                    |   9        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Larynx                                  |                                                                          |   1        |
      Hemorrhage                           |                                                                          |      1  4.0|
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Atelectasis                          |                                                                          |      1  2.0|
      Crystals                             |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  98                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Hemorrhage                           |                                                                          |      3  1.7|
      Hyperplasia, Macrophage              |                                                                          |      6  1.7|
      Hyperplasia, Adenomatous             |                                                                          |      1  3.0|
      Inflammation, Suppurative            |                                                                          |      1  2.0|
      Mineralization                       |                                                                          |      2  1.0|
      Necrosis, Liquifactive               |                                                                          |      1  2.0|
      Proliferation Connective Tissue      |                                                                          |      1  3.0|
      Arteriole, Thrombosis                |    2                                                                     |      2  2.0|
      Interstitium, Fibrosis               |                                                                          |      1  2.0|
      Interstitium, Inflammation, Chronic  |                                                                          |      1  2.0|
      Pleura, Inflammation, Chronic        |                                                                          |      2  1.5|
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                | 2                                                                        |      6  2.2|
      Inflammation, Suppurative            |                                                                          |      2  3.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Chronic                         | 1  2  1  2     2  3           2  1  1  2                                 |     34  1.9|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                   2                                                      |      2  1.5|
      Nasolacrimal Duct, Metaplasia,       |                                                                          |            |
          Squamous                         | 1  2  1  2     4  4  2  3     4  3  1  2                                 |     47  2.4|
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                |                                                                          |      1  2.0|
      Glands, Cyst                         |    3                                                                     |      2  2.5|
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Eye                                     |                      +                 +                                 |   4        |
      Cornea, Inflammation, Subacute       |                      2                                                   |      1  2.0|
      Cornea, Necrosis                     |                      2                                                   |      1  2.0|
      Retina, Atrophy                      |                      4                                                   |      2  4.0|
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   3        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Cyst                                 |                   2              2                                       |      6  2.5|
      Hemorrhage                           |                                                                          |      1  2.0|
      Inflammation, Chronic                |       2        2  2  2  1     3  2                                       |     27  1.9|
      Nephropathy                          | 4  4  4  3     4  4  4  4     4  4  1  1                                 |     55  3.4|
      Pelvis, Inflammation, Suppurative    |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page  99                                                               
NTP Experiment-Test: 05040-01                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                            HYDROQUINONE                                       Date: 05/01/97  
Route: GAVAGE                                                                                                     Time: 09:41:17  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 6| 4| 4| 7| 6| 6| 5| 4| 7| 7| 6| 5| 4|                             |            |
                             DAY ON TEST   | 0| 3| 7| 7| 5| 3| 7| 3| 9| 5| 3| 1| 5| 5| 5|                             |            |
                                           | 2| 1| 2| 3| 9| 2| 6| 8| 8| 9| 2| 8| 1| 6| 9|                             |      T (*) |
 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      O     |
   FISCHER 344 RATS MALE                   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                             |      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                             |      A     |
    50 MG/KG                               | 7| 7| 7| 7| 7| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9|                             |      L     |
                                           | 1| 2| 3| 4| 5| 1| 2| 3| 4| 5| 1| 2| 3| 4| 5|                             |            |
 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Renal Tubule, Hyperplasia, Focal     |                                                                          |      1  2.0|
      Renal Tubule, Hyperplasia            |                                                                          |      1  2.0|
      Transitional Epithelium, Hyperplasia,|                                                                          |            |
           Papillary                       |    2           2                                                         |      5  2.2|
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +     +  +  +  +     +  +  +  +                                 |  55        |
      Inflammation, Chronic                |                               1                                          |      3  1.0|
      Inflammation, Chronic Active         |                                                                          |      1  3.0|
      Submucosa, Edema                     |                                                                          |      1  2.0|
 __________________________________________________________________________________________________________________________________ 
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                             Page 100                                                               
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