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TDMS Study 55301-06 Pathology Tables

NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97
Route: DOSED WATER                                                                                                Time: 12:18:28




       Facility:  TSI Mason Research

       Chemical CAS #:  110-86-1

       Lock Date:  12/13/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































Note:  Animals arranged according to CID number

                                                              Page   1


NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 5| 7| 6| 7| 6| 7| 7| 7| 7| 7| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7|             
                             DAY ON TEST   | 8| 2| 5| 2| 5| 2| 7| 2| 2| 2| 2| 2| 6| 0| 2| 2| 2| 2| 1| 2| 0| 2| 4| 1| 0|             
                                           | 9| 2| 7| 2| 4| 2| 6| 2| 2| 2| 2| 2| 8| 1| 2| 2| 2| 2| 7| 2| 7| 2| 4| 6| 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|             
   WISTAR OUTBRED 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|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  A  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  A  +  A  A  A|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  A  +  +  A  A|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  A  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  M  +  A  A  A|             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  A  +  A  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  A  +  A  A  A|             
      Carcinoma                            |                         X                                                |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  A  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  A  +  A  +  A  A  A|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cholangiocarcinoma                   |                                                          X               |             
      Hepatocellular Adenoma               |             X                                      X                     |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                     +  +              +     +            |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             | +           +        +                    +                              |             
      Squamous Cell Carcinoma              | X                                                                        |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  A  +  +|             
      Acinus, Adenoma                      |                X                          X     X        X               |             
      Acinus, Adenoma, Multiple            | X        X           X     X     X           X                           |             
      Acinus, Carcinoma                    |                      X                                                   |             
      Acinus, Carcinoma, Multiple          |                                                    X                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
                                            __________________________________________________________________________|             
   Tooth                                   |                                                          +               |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            |       +                             +  +              +                  |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Endocardium, Schwannoma Benign       |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                      X  X     X                                X         |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  A  +  +|             
      Adenoma                              |                X     X           X                    X  X               |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Adenoma                              |                                                 X                        |             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X     X  X  X     X  X     X           X                    X   |             
      Pars Distalis, Adenoma, Multiple     |                                                                          |             
      Pars Intermedia, Adenoma             |                                           X                              |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page   2                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 5| 7| 6| 7| 6| 7| 7| 7| 7| 7| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7|             
                             DAY ON TEST   | 8| 2| 5| 2| 5| 2| 7| 2| 2| 2| 2| 2| 6| 0| 2| 2| 2| 2| 1| 2| 0| 2| 4| 1| 0|             
                                           | 9| 2| 7| 2| 4| 2| 6| 2| 2| 2| 2| 2| 8| 1| 2| 2| 2| 2| 7| 2| 7| 2| 4| 6| 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|             
   WISTAR OUTBRED 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|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      C-Cell, Adenoma                      |          X                                                     X         |             
      Follicular Cell, Carcinoma           |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                 X                        |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |    X                                         X                           |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Interstitial Cell, Adenoma|                X              X                             X            |             
      Interstitial Cell, Adenoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +     +           +           +  +  +  +        +  +  +     +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  A  +  +  +  +  +  +  +  +  +  M  A  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X                        |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  M  +|             
      Thymoma Benign                       |                X                                                         |             
      Thymoma Malignant                    |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Fibroadenoma                         |                                                          X               |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Keratoacanthoma                      |                                           X  X        X  X               |             
      Squamous Cell Papilloma              |          X                                                               |             
      Subcutaneous Tissue, Fibroma         |    X                                      X              X               |             
      Subcutaneous Tissue, Sarcoma         |                                                                   X      |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cranium, Osteoma                     |                                        X                                 |             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                 +                        |             
      Lipoma                               |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   3                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 5| 7| 6| 7| 6| 7| 7| 7| 7| 7| 4| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7|             
                             DAY ON TEST   | 8| 2| 5| 2| 5| 2| 7| 2| 2| 2| 2| 2| 6| 0| 2| 2| 2| 2| 1| 2| 0| 2| 4| 1| 0|             
                                           | 9| 2| 7| 2| 4| 2| 6| 2| 2| 2| 2| 2| 8| 1| 2| 2| 2| 2| 7| 2| 7| 2| 4| 6| 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|             
   WISTAR OUTBRED 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|             
    0 PPM                                  | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Astrocytoma Malignant                |                   X                                                      |             
      Hemangioma                           |                                                                         X|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Squamous Cell Carcinoma, Metastatic, |                                                                          |             
           Oral Mucosa                     | X                                                                        |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                     +                                    |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                  +                                       |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                          |             
      Carcinoma                            |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lipoma                               |                                                                          |             
      Renal Tubule, Adenoma                |                                                                          |             
      Renal Tubule, Adenoma, Multiple      |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   4                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 5| 7| 6| 5| 6| 7| 7| 6| 2| 7| 5| 6| 7| 5| 7| 5| 6| 7| 6| 5| 6| 7| 5|            |
                             DAY ON TEST   | 0| 6| 9| 2| 3| 7| 1| 2| 2| 9| 8| 2| 9| 8| 2| 7| 2| 8| 7| 2| 2| 5| 4| 2| 3|            |
                                           | 1| 0| 8| 2| 9| 6| 8| 2| 2| 5| 3| 2| 2| 1| 2| 2| 2| 7| 4| 2| 4| 9| 4| 2| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  A  +  +  +  +  A  A  +  +  +  +  +  +  A  +  +  +  A  A  +  A|  35        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  42        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  A  +  +  +  +  A  A  +  A  +  +  A  +  A  +  +  A  A  A  +  A|  32        |
      Carcinoma                            |                      X                                                   |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  A  A  +  +  +  +  +  +  A  +  +  +  A  A  +  +|  39        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  A  +  A  +  +  A  A  +  +  +  +  +  +  +  +  +  +  A  A  +  +|  37        |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  A  A  +  A  +  A  +  +  A  A  +  A  A  +  A  +  A  A  +  +  A  A  +  +|  28        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cholangiocarcinoma                   |                                                                          |          1 |
      Hepatocellular Adenoma               |                                                                          |          2 |
                                            __________________________________________________________________________|____________|
   Mesentery                               | +                          +                             +               |   7        |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +                                                                        |   5        |
      Squamous Cell Carcinoma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Acinus, Adenoma                      |                         X                 X                              |          6 |
      Acinus, Adenoma, Multiple            |                                  X              X                        |          8 |
      Acinus, Carcinoma                    |                                                                      X   |          2 |
      Acinus, Carcinoma, Multiple          |                                                 X                        |          2 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                         +                                                |   2        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            |                +  +        +                                   +         |   8        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Endocardium, Schwannoma Benign       |          X                                                           X   |          2 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pheochromocytoma Malignant           |                                                    X                     |          1 |
      Pheochromocytoma Benign              |                                  X                                       |          5 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Adenoma                              |          X                                            X     X            |          8 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Adenoma                              |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   5                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 5| 7| 6| 5| 6| 7| 7| 6| 2| 7| 5| 6| 7| 5| 7| 5| 6| 7| 6| 5| 6| 7| 5|            |
                             DAY ON TEST   | 0| 6| 9| 2| 3| 7| 1| 2| 2| 9| 8| 2| 9| 8| 2| 7| 2| 8| 7| 2| 2| 5| 4| 2| 3|            |
                                           | 1| 0| 8| 2| 9| 6| 8| 2| 2| 5| 3| 2| 2| 1| 2| 2| 2| 7| 4| 2| 4| 9| 4| 2| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Adenoma               |          X                       X     X              X        X  X      |         15 |
      Pars Distalis, Adenoma, Multiple     |                         X                                                |          1 |
      Pars Intermedia, Adenoma             |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Adenoma                      | X                                               X                        |          4 |
      Follicular Cell, Carcinoma           |                         X                             X                  |          3 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       | +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                      X                                                   |          3 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Bilateral, Interstitial Cell, Adenoma|                                                                          |          3 |
      Interstitial Cell, Adenoma           |                                     X                                X   |          2 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +     +     +  +        +  +  +  +  +        +     +  +     +     +  +|  31        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  46        |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Thymoma Benign                       |                                                                          |          1 |
      Thymoma Malignant                    |                                                             X            |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Fibroadenoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Keratoacanthoma                      |       X                          X     X                                 |          7 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   6                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 5| 7| 6| 5| 6| 7| 7| 6| 2| 7| 5| 6| 7| 5| 7| 5| 6| 7| 6| 5| 6| 7| 5|            |
                             DAY ON TEST   | 0| 6| 9| 2| 3| 7| 1| 2| 2| 9| 8| 2| 9| 8| 2| 7| 2| 8| 7| 2| 2| 5| 4| 2| 3|            |
                                           | 1| 0| 8| 2| 9| 6| 8| 2| 2| 5| 3| 2| 2| 1| 2| 2| 2| 7| 4| 2| 4| 9| 4| 2| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    0 PPM                                  | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Squamous Cell Papilloma              |                X                                                         |          2 |
      Subcutaneous Tissue, Fibroma         | X                                            X                           |          5 |
      Subcutaneous Tissue, Sarcoma         |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cranium, Osteoma                     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                          |   1        |
      Lipoma                               |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Astrocytoma Malignant                |                                                                          |          1 |
      Hemangioma                           |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Squamous Cell Carcinoma, Metastatic, |                                                                          |            |
           Oral Mucosa                     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |    +                                                                     |   1        |
      Carcinoma                            |    X                                                                     |          1 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Lipoma                               |                         X                                                |          1 |
      Renal Tubule, Adenoma                | X                                                                        |          1 |
      Renal Tubule, Adenoma, Multiple      |                X                                                         |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +  +|  47        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page   7                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 5| 6| 6| 7| 6| 4| 6| 5| 7| 7| 3| 6| 5| 6| 7| 7| 7| 5| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 4| 4| 4| 3| 9| 2| 3| 8| 5| 7| 2| 2| 7| 3| 9| 6| 1| 2| 2| 9| 1| 1| 2| 2| 2|             
                                           | 9| 2| 1| 9| 0| 2| 8| 6| 1| 3| 2| 2| 2| 4| 3| 0| 6| 2| 2| 5| 4| 1| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    100 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  +  +  +  A  +  +  +  A  A  +  +  +  +  A  +  +  +  +  A  A  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | A  +  +  +  A  +  +  +  A  A  +  +  +  +  A  +  +  +  +  A  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  +  A  A  +  +  +  A  +  +  +  +  +  A  A  +  +  +  A  +  A  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +  A  +  +  +  +  A  +  +  +|             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  A  +  +  +  A  A  +  +  +  A  A  +  A  +  +  +  A  A  +  +  +|             
      Carcinoma                            |                                                                   X      |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  +  A  A  +  +  +  A  A  +  +  +  A  A  +  +  +  +  A  A  A  +  +  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Mesentery                               |                            +                                             |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            |                   X                                                      |             
      Acinus, Adenoma                      |          X     X              X     X                                    |             
      Acinus, Adenoma, Multiple            |                   X                                   X                  |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tooth                                   |                                  +                                       |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            |    +  +  +  +        +  +              +        +           +  +         |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Endocardium, Schwannoma Benign       |                                           X                              |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                       X                  |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                      X           X           X                           |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            |                   X                                                      |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |             X     X           X                 X        X  X  X         |             
      Pars Distalis, Adenoma, Multiple     |                                                    X                     |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                               X                                          |             
      Follicular Cell, Carcinoma           | X              X                          X                              |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Tissue NOS                              |                                              +                           |             
 _____________________________________________________________________________________________________________________|             

                                                             Page   8                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 5| 6| 6| 7| 6| 4| 6| 5| 7| 7| 3| 6| 5| 6| 7| 7| 7| 5| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 4| 4| 4| 3| 9| 2| 3| 8| 5| 7| 2| 2| 7| 3| 9| 6| 1| 2| 2| 9| 1| 1| 2| 2| 2|             
                                           | 9| 2| 1| 9| 0| 2| 8| 6| 1| 3| 2| 2| 2| 4| 3| 0| 6| 2| 2| 5| 4| 1| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    100 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM - cont                |                                                                          |             
                                           |                                                                          |             
      Hemangiosarcoma                      |                                              X                           |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       | +  +  +  +  M  +  +  +  +  +  +  +  M  +  +  +  M  +  M  +  M  +  +  M  +|             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Penis                                   |             +                                                            |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                       X                  |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Interstitial Cell, Adenoma|                                                                      X   |             
      Interstitial Cell, Adenoma           |          X     X     X                       X                           |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node                              | +  +  +  +     +  +  +  +  +  +  +  +     +  +  +  +  +  +  +  +  +  +  +|             
      Iliac, Hemangiosarcoma               |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangiosarcoma                      |                                                                          |             
      Lymphoma Malignant                   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangiosarcoma                      |                                              X                           |             
      Leukemia Mononuclear                 |                                                                          |             
      Lymphoma Malignant                   |                                  X                                       |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lymphoma Malignant                   |          X                       X                                       |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Fibroadenoma                         |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Adenoma                   |                                                                          |             
      Keratoacanthoma                      |          X                                                        X      |             
      Squamous Cell Carcinoma              |                                  X                                       |             
      Squamous Cell Papilloma              |                                                                          |             
      Subcutaneous Tissue, Fibroma         |                               X  X     X           X                     |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page   9                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 6| 5| 6| 6| 7| 6| 4| 6| 5| 7| 7| 3| 6| 5| 6| 7| 7| 7| 5| 7| 6| 7| 7| 7|             
                             DAY ON TEST   | 4| 4| 4| 3| 9| 2| 3| 8| 5| 7| 2| 2| 7| 3| 9| 6| 1| 2| 2| 9| 1| 1| 2| 2| 2|             
                                           | 9| 2| 1| 9| 0| 2| 8| 6| 1| 3| 2| 2| 2| 4| 3| 0| 6| 2| 2| 5| 4| 1| 2| 2| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    100 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Astrocytoma Malignant                |                                                                          |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |    +  +                                                                  |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |    +  +                                                                  |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Renal Tubule, Adenoma                |          X                                                               |             
      Renal Tubule, Adenoma, Multiple      |                                                                          |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Lymphoma Malignant                   |          X                       X                                       |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  10                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 5| 5| 3| 4| 3| 7| 6| 6| 7| 6| 5| 7| 7| 6| 5| 6| 7| 6| 4| 7| 5| 6| 5|            |
                             DAY ON TEST   | 2| 4| 3| 8| 3| 7| 5| 1| 8| 1| 2| 9| 6| 2| 2| 6| 4| 7| 2| 9| 7| 2| 5| 4| 0|            |
                                           | 2| 5| 6| 1| 6| 9| 2| 0| 2| 0| 2| 8| 1| 2| 2| 8| 9| 9| 2| 7| 0| 2| 2| 7| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 1|     A      |
    100 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  A  +  +  +  +|  39        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  42        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  A  +  +  +  +  A  +  A  +  +  +  +  +  +  +  +  +  +  A  A  +  +  +  +|  37        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  A  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  44        |
      Carcinoma                            |                                  X                                       |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  A  +  +  +  A  +  +  A  +  +  +  +  +  +  +  A  +  +  A  A  +  +  +  +|  36        |
      Carcinoma                            |                                                                X         |          2 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  A  +  +  +  A  A  +  A  +  +  +  +  +  +  +  +  +  +  A  A  +  A  A  +|  32        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                        +                                 |   1        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma                            |                                                                          |          1 |
      Acinus, Adenoma                      |                            X                    X                       X|          7 |
      Acinus, Adenoma, Multiple            |    X                                                  X                  |          4 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                           +                              |   2        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            |    +  +        +  +        +  +     +        +  +  +     +     +        +|  23        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Endocardium, Schwannoma Benign       |                                                       X                  |          2 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pheochromocytoma Malignant           |                                  X                                       |          1 |
      Pheochromocytoma Benign              | X                                                                        |          4 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Adenoma               |                      X           X  X     X  X        X  X     X        X|         16 |
      Pars Distalis, Adenoma, Multiple     |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  11                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 5| 5| 3| 4| 3| 7| 6| 6| 7| 6| 5| 7| 7| 6| 5| 6| 7| 6| 4| 7| 5| 6| 5|            |
                             DAY ON TEST   | 2| 4| 3| 8| 3| 7| 5| 1| 8| 1| 2| 9| 6| 2| 2| 6| 4| 7| 2| 9| 7| 2| 5| 4| 0|            |
                                           | 2| 5| 6| 1| 6| 9| 2| 0| 2| 0| 2| 8| 1| 2| 2| 8| 9| 9| 2| 7| 0| 2| 2| 7| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 1|     A      |
    100 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      C-Cell, Adenoma                      |          X                                                               |          2 |
      Follicular Cell, Carcinoma           |                                                                          |          3 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Tissue NOS                              |                                                                          |   1        |
      Hemangiosarcoma                      |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +|  42        |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Bilateral, Interstitial Cell, Adenoma|                                                                          |          1 |
      Interstitial Cell, Adenoma           |                               X                                          |          5 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +     +  +  +  +  +     +  +  +  +  +  +  +  +  +  +     +  +   |  44        |
      Iliac, Hemangiosarcoma               |                                        X                                 |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemangiosarcoma                      |                                           X                              |          1 |
      Lymphoma Malignant                   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemangiosarcoma                      |                                                                          |          1 |
      Leukemia Mononuclear                 |                                                                   X      |          1 |
      Lymphoma Malignant                   |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Lymphoma Malignant                   |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  46        |
      Fibroadenoma                         |                                                                         X|          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basal Cell Adenoma                   |                                        X                                 |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  12                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 4| 5| 5| 3| 4| 3| 7| 6| 6| 7| 6| 5| 7| 7| 6| 5| 6| 7| 6| 4| 7| 5| 6| 5|            |
                             DAY ON TEST   | 2| 4| 3| 8| 3| 7| 5| 1| 8| 1| 2| 9| 6| 2| 2| 6| 4| 7| 2| 9| 7| 2| 5| 4| 0|            |
                                           | 2| 5| 6| 1| 6| 9| 2| 0| 2| 0| 2| 8| 1| 2| 2| 8| 9| 9| 2| 7| 0| 2| 2| 7| 6|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 1|     A      |
    100 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Keratoacanthoma                      | X                                                                        |          3 |
      Squamous Cell Carcinoma              |                                                                          |          1 |
      Squamous Cell Papilloma              |                               X                                          |          1 |
      Subcutaneous Tissue, Fibroma         | X                                                                 X      |          6 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Astrocytoma Malignant                | X                                                                        |          1 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                    +                    +|   4        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                    +                    +|   4        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Renal Tubule, Adenoma                |                            X              X              X               |          4 |
      Renal Tubule, Adenoma, Multiple      |                                                    X                     |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |                                                                   X      |          1 |
      Lymphoma Malignant                   |                                                                          |          2 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  13                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 6| 4| 5| 6| 7| 7| 6| 3| 4| 6| 7| 7| 6| 5| 6| 7| 7| 6| 5| 7|             
                             DAY ON TEST   | 5| 2| 8| 2| 2| 3| 8| 2| 8| 2| 0| 2| 5| 0| 0| 2| 2| 7| 0| 8| 2| 0| 2| 4| 2|             
                                           | 0| 2| 7| 2| 2| 2| 6| 0| 3| 2| 0| 8| 4| 4| 8| 2| 2| 4| 1| 2| 1| 4| 2| 8| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    200 PPM                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  +  A  +  +  A  A  +  +  +  A  +  +  +  A  +  +  A  +  +  +  +  A  A  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | A  +  A  +  +  A  A  +  +  +  A  +  +  +  +  +  +  A  +  +  +  +  A  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  +  A  +  +  A  A  +  +  +  A  +  +  +  A  +  +  A  +  A  +  +  A  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  A  +  +  A  A  +  +  +  A  A  +  +  A  +  +  +  +  +  +  +  A  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  +  A  +  +  A  A  +  +  +  A  A  +  +  A  +  +  A  +  A  +  +  A  A  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hepatocellular Adenoma               |    X                                                                     |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |          +              +                                                |             
                                            __________________________________________________________________________|             
   Oral Mucosa                             |                               +                                          |             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
      Acinus, Adenoma                      | X        X     X  X                       X                 X            |             
      Acinus, Adenoma, Multiple            |    X                                            X                       X|             
      Acinus, Carcinoma                    |          X                                                               |             
      Acinus, Carcinoma, Multiple          |    X                                                                     |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Fibrosarcoma                         |                         X                                                |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Fibrosarcoma, Metastatic, Stomach,   |                                                                          |             
           Forestomach                     |                         X                                                |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Tongue                                  |                                                                          |             
      Squamous Cell Carcinoma              |                                                                          |             
                                            __________________________________________________________________________|             
   Tooth                                   |                +                    +                                   +|             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            |                   +              +  +     +           +     +     +      |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
      Pheochromocytoma Benign              |                                                             X            |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  14                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 6| 4| 5| 6| 7| 7| 6| 3| 4| 6| 7| 7| 6| 5| 6| 7| 7| 6| 5| 7|             
                             DAY ON TEST   | 5| 2| 8| 2| 2| 3| 8| 2| 8| 2| 0| 2| 5| 0| 0| 2| 2| 7| 0| 8| 2| 0| 2| 4| 2|             
                                           | 0| 2| 7| 2| 2| 2| 6| 0| 3| 2| 0| 8| 4| 4| 8| 2| 2| 4| 1| 2| 1| 4| 2| 8| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    200 PPM                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM - cont                   |                                                                          |             
                                           |                                                                          |             
      Adenoma                              |                                                          X               |             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |          X     X                                   X     X     X        X|             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Follicular Cell, Adenoma  |                                                    X                     |             
      Follicular Cell, Adenoma             |          X                    X                                          |             
      Follicular Cell, Carcinoma           |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       | M  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |    X                                                                     |             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                      X   |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                            X                                             |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mesothelioma Malignant               |    X                                                                     |             
      Bilateral, Interstitial Cell, Adenoma|                                                                          |             
      Interstitial Cell, Adenoma           |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node                              |    +  +  +  +  +  +  +        +     +        +  +  +  +     +  +  +  +  +|             
      Mediastinal, Leukemia Mononuclear    |                                                                          |             
      Pancreatic, Leukemia Mononuclear     |                                                                          |             
      Renal, Leukemia Mononuclear          |                                                                          |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangiosarcoma                      |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +|             
      Leukemia Mononuclear                 |                                                    X                     |             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Thymoma Benign                       | X                                                                    X   |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  15                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 6| 4| 5| 6| 7| 7| 6| 3| 4| 6| 7| 7| 6| 5| 6| 7| 7| 6| 5| 7|             
                             DAY ON TEST   | 5| 2| 8| 2| 2| 3| 8| 2| 8| 2| 0| 2| 5| 0| 0| 2| 2| 7| 0| 8| 2| 0| 2| 4| 2|             
                                           | 0| 2| 7| 2| 2| 2| 6| 0| 3| 2| 0| 8| 4| 4| 8| 2| 2| 4| 1| 2| 1| 4| 2| 8| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    200 PPM                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  M  +  M  +  +  +  +  +|             
      Carcinoma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Zymbal's Gland|                                                                          |             
      Fibroma                              |                         X  X                                             |             
      Keratoacanthoma                      |          X                                                               |             
      Squamous Cell Papilloma              |                                                                      X   |             
      Sebaceous Gland, Adenoma             |             X                                                            |             
      Subcutaneous Tissue, Fibrosarcoma    |                                                    X                     |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                         +|             
      Fibroma                              |                                                                          |             
      Lipoma                               |                                                                         X|             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Astrocytoma Malignant                |                         X                                                |             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                       +     +            |             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                       +     +            |             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Carcinoma       |                                                                          |             
      Carcinoma, Metastatic, Zymbal's Gland|                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Eye                                     |                                                                          |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                     +                 +                  |             
                                            __________________________________________________________________________|             
   Lacrimal Gland                          |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                         +                                                |             
      Carcinoma                            |                         X                                                |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Alveolar/Bronchiolar Carcinoma,      |                                                                          |             
          Metastatic, Lung                 |                                                                          |             
      Leukemia Mononuclear                 |                                                                          |             
      Renal Tubule, Adenoma                |                                                             X            |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  16                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 6| 7| 4| 7| 7| 6| 4| 5| 6| 7| 7| 6| 3| 4| 6| 7| 7| 6| 5| 6| 7| 7| 6| 5| 7|             
                             DAY ON TEST   | 5| 2| 8| 2| 2| 3| 8| 2| 8| 2| 0| 2| 5| 0| 0| 2| 2| 7| 0| 8| 2| 0| 2| 4| 2|             
                                           | 0| 2| 7| 2| 2| 2| 6| 0| 3| 2| 0| 8| 4| 4| 8| 2| 2| 4| 1| 2| 1| 4| 2| 8| 2|             
 _____________________________________________________________________________________________________________________|             
                                           | 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|             
   WISTAR OUTBRED 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|             
    200 PPM                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  A  +  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Leukemia Mononuclear                 |                                                    X                     |             
      Mesothelioma Malignant               |    X                                                                     |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  17                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 4| 5| 5| 4| 5| 7| 7| 7| 5| 5| 7| 7| 6| 6| 6| 4| 6| 6| 4| 6| 4| 6|            |
                             DAY ON TEST   | 2| 1| 1| 4| 0| 1| 9| 7| 2| 0| 0| 6| 8| 2| 2| 6| 8| 7| 8| 3| 3| 7| 6| 7| 4|            |
                                           | 2| 5| 3| 7| 0| 0| 4| 5| 2| 4| 5| 1| 8| 2| 2| 0| 8| 5| 1| 0| 1| 9| 4| 3| 5|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    200 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  A  +  +  +  +  +  A  +  +  +  A  +  A  +  +  A  +  +  +  +|  36        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +|  41        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  A  +  +  M  +  A  A  A  +  +  A  A  A  +  +  A  +  A  +  A|  29        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  A  A  A  +  +  +  +  A  +  +  A  +  +  +  +|  42        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  A  +  +  A  A  A  +  +  +  A  A  +  +  A  +  A  +  +|  34        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  A  +  A  +  A  +  +  A  A  +  +  +  +  A  A  +  A  A  +  A  +  A|  28        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hepatocellular Adenoma               |                                                                          |          1 |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
      Acinus, Adenoma                      |                X              X                                          |          8 |
      Acinus, Adenoma, Multiple            |                                                          X               |          4 |
      Acinus, Carcinoma                    | X                                                                        |          2 |
      Acinus, Carcinoma, Multiple          |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  M  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Fibrosarcoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Fibrosarcoma, Metastatic, Stomach,   |                                                                          |            |
           Forestomach                     |                                                                          |          1 |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Tongue                                  |                            +                                             |   1        |
      Squamous Cell Carcinoma              |                            X                                             |          1 |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                            +                                             |   4        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            |             +  +                                   +     +        +      |  12        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  18                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 4| 5| 5| 4| 5| 7| 7| 7| 5| 5| 7| 7| 6| 6| 6| 4| 6| 6| 4| 6| 4| 6|            |
                             DAY ON TEST   | 2| 1| 1| 4| 0| 1| 9| 7| 2| 0| 0| 6| 8| 2| 2| 6| 8| 7| 8| 3| 3| 7| 6| 7| 4|            |
                                           | 2| 5| 3| 7| 0| 0| 4| 5| 2| 4| 5| 1| 8| 2| 2| 0| 8| 5| 1| 0| 1| 9| 4| 3| 5|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    200 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pheochromocytoma Malignant           |                                                       X                  |          1 |
      Pheochromocytoma Benign              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Adenoma                              |                X                             X                           |          3 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pars Distalis, Adenoma               |    X              X     X              X           X                    X|         12 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Bilateral, Follicular Cell, Adenoma  |                                                                          |          1 |
      Follicular Cell, Adenoma             |                                                          X        X      |          4 |
      Follicular Cell, Carcinoma           |                                                                         X|          1 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       | +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  49        |
      Mesothelioma Malignant               |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  49        |
      Mesothelioma Malignant               |                                                                          |          1 |
      Bilateral, Interstitial Cell, Adenoma|                                                    X                     |          1 |
      Interstitial Cell, Adenoma           |                            X                 X                           |          3 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              |    +  +  +  +  +  +  +        +  +  +  +  +  +  +  +     +  +  +  +     +|  38        |
      Mediastinal, Leukemia Mononuclear    |       X                                                                  |          1 |
      Pancreatic, Leukemia Mononuclear     |       X                                                                  |          1 |
      Renal, Leukemia Mononuclear          |       X                                                                  |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  19                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 4| 5| 5| 4| 5| 7| 7| 7| 5| 5| 7| 7| 6| 6| 6| 4| 6| 6| 4| 6| 4| 6|            |
                             DAY ON TEST   | 2| 1| 1| 4| 0| 1| 9| 7| 2| 0| 0| 6| 8| 2| 2| 6| 8| 7| 8| 3| 3| 7| 6| 7| 4|            |
                                           | 2| 5| 3| 7| 0| 0| 4| 5| 2| 4| 5| 1| 8| 2| 2| 0| 8| 5| 1| 0| 1| 9| 4| 3| 5|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    200 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  M  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemangiosarcoma                      |                               X                                          |          1 |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Leukemia Mononuclear                 |       X                                                                  |          2 |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Thymoma Benign                       |                                                                          |          2 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|  44        |
      Carcinoma                            |                                                    X                     |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma, Metastatic, Zymbal's Gland|                   X                                                      |          1 |
      Fibroma                              |                                                                          |          2 |
      Keratoacanthoma                      |                               X                                          |          2 |
      Squamous Cell Papilloma              |                                                                          |          1 |
      Sebaceous Gland, Adenoma             |                                                                          |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                         +|   2        |
      Fibroma                              |                                                                         X|          1 |
      Lipoma                               |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Astrocytoma Malignant                |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   2        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   2        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Carcinoma       |                            X                                             |          1 |
      Carcinoma, Metastatic, Zymbal's Gland|                   X                                                      |          1 |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  20                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 4| 5| 5| 4| 5| 7| 7| 7| 5| 5| 7| 7| 6| 6| 6| 4| 6| 6| 4| 6| 4| 6|            |
                             DAY ON TEST   | 2| 1| 1| 4| 0| 1| 9| 7| 2| 0| 0| 6| 8| 2| 2| 6| 8| 7| 8| 3| 3| 7| 6| 7| 4|            |
                                           | 2| 5| 3| 7| 0| 0| 4| 5| 2| 4| 5| 1| 8| 2| 2| 0| 8| 5| 1| 0| 1| 9| 4| 3| 5|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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|     A      |
    200 PPM                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |    +                                                                     |   1        |
                                            __________________________________________________________________________|____________|
   Eye                                     |                   +                                                      |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                        +                                +|   4        |
                                            __________________________________________________________________________|____________|
   Lacrimal Gland                          |                   +                                                      |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                   +                                                      |   2        |
      Carcinoma                            |                   X                                                      |          2 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Alveolar/Bronchiolar Carcinoma,      |                                                                          |            |
          Metastatic, Lung                 |                            X                                             |          1 |
      Leukemia Mononuclear                 |       X                                                                  |          1 |
      Renal Tubule, Adenoma                |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Leukemia Mononuclear                 |       X                                                                  |          2 |
      Mesothelioma Malignant               |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  21                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 7| 5| 7| 7| 5| 4| 6| 7| 4| 6| 6| 4| 5| 4| 7| 6| 5| 5| 4| 5| 7| 6| 6|             
                             DAY ON TEST   | 0| 8| 2| 3| 2| 2| 9| 4| 0| 2| 5| 7| 8| 9| 5| 8| 2| 8| 3| 3| 6| 6| 2| 8| 3|             
                                           | 9| 7| 2| 9| 2| 2| 5| 3| 6| 2| 0| 4| 2| 9| 0| 6| 2| 5| 2| 1| 7| 8| 2| 7| 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|             
   WISTAR OUTBRED 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|             
    400 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | A  A  +  +  +  +  +  A  +  +  A  A  A  +  +  A  +  A  +  A  +  A  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | A  A  +  +  +  +  +  A  +  +  A  A  A  +  +  +  +  A  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | A  A  +  A  +  +  +  A  A  +  A  A  A  +  +  A  +  A  +  A  +  A  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | A  +  +  +  +  +  +  A  +  +  A  A  +  +  +  +  +  A  +  A  +  +  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | A  A  +  +  +  +  +  A  +  +  A  A  A  +  +  +  +  A  +  A  +  A  +  A  +|             
                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | A  A  +  +  +  +  +  A  A  +  A  A  A  +  +  +  +  A  +  A  +  A  +  A  +|             
                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cholangiocarcinoma                   |                                                                          |             
      Histiocytic Sarcoma                  |          X                                                               |             
      Lymphoma Malignant                   |                                                                          |             
                                            __________________________________________________________________________|             
   Mesentery                               |                                                                         +|             
                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Acinus, Adenoma                      |       X        X           X              X                    X         |             
                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Squamous Cell Papilloma              |                                                          X               |             
                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Tooth                                   | +                          +                                             |             
 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Blood Vessel                            |                         +              +     +                           |             
                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Endocardium, Schwannoma Benign       | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma                            | X                                                                        |             
                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pheochromocytoma Malignant           |                                                                          |             
                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
      Carcinoma                            |                                                                         X|             
                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Adenoma               |                   X              X              X     X                 X|             
      Pars Intermedia, Adenoma             |                                                                      X   |             
                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Adenoma                      |                                                 X                        |             
 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Coagulating Gland                       | M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             

                                                             Page  22                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 7| 5| 7| 7| 5| 4| 6| 7| 4| 6| 6| 4| 5| 4| 7| 6| 5| 5| 4| 5| 7| 6| 6|             
                             DAY ON TEST   | 0| 8| 2| 3| 2| 2| 9| 4| 0| 2| 5| 7| 8| 9| 5| 8| 2| 8| 3| 3| 6| 6| 2| 8| 3|             
                                           | 9| 7| 2| 9| 2| 2| 5| 3| 6| 2| 0| 4| 2| 9| 0| 6| 2| 5| 2| 1| 7| 8| 2| 7| 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|             
   WISTAR OUTBRED 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|             
    400 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Adenoma                              |                                                                   X      |             
                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Schwannoma Malignant                 |                                  X                                       |             
                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Bilateral, Interstitial Cell, Adenoma| X  X                                            X        X        X      |             
      Interstitial Cell, Adenoma           |                                        X                                 |             
 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |          X                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node                              |          +  +  +                 +     +  +  +  +  +     +  +  +     +   |             
      Pancreatic, Histiocytic Sarcoma      |          X                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|             
      Histiocytic Sarcoma                  |          X                                                               |             
                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemangioma                           |                                                                         X|             
      Histiocytic Sarcoma                  |          X                                                               |             
                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Lymphoma Malignant                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Mammary Gland                           | M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +|             
      Fibroadenoma                         |                                                                         X|             
                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basal Cell Carcinoma                 |             X                                                            |             
      Keratoacanthoma                      |                                                                      X   |             
      Subcutaneous Tissue, Fibroma         |                X                                                         |             
      Subcutaneous Tissue, Fibroma,        |                                                                          |             
          Multiple                         |                            X                                             |             
      Subcutaneous Tissue, Fibrosarcoma    | X                                                                        |             
 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Joint, Sarcoma                       |                            X                                             |             
 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                            +                          +                 +|             
                                            __________________________________________________________________________|             
   Spinal Cord                             |                            +                          +                 +|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  23                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 _____________________________________________________________________________________________________________________              
                                           | 7| 5| 7| 5| 7| 7| 5| 4| 6| 7| 4| 6| 6| 4| 5| 4| 7| 6| 5| 5| 4| 5| 7| 6| 6|             
                             DAY ON TEST   | 0| 8| 2| 3| 2| 2| 9| 4| 0| 2| 5| 7| 8| 9| 5| 8| 2| 8| 3| 3| 6| 6| 2| 8| 3|             
                                           | 9| 7| 2| 9| 2| 2| 5| 3| 6| 2| 0| 4| 2| 9| 0| 6| 2| 5| 2| 1| 7| 8| 2| 7| 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|             
   WISTAR OUTBRED 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|             
    400 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             
 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Carcinoma, Metastatic, Zymbal's Gland|                                                                          |             
      Fibrosarcoma, Metastatic, Skin       | X                                                                        |             
      Histiocytic Sarcoma                  |          X                                                               |             
                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Chondroma                            |                                                                          |             
                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Ear                                     |                                                       +                  |             
                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             
                                            __________________________________________________________________________|             
   Zymbal's Gland                          |                                                                      +   |             
      Carcinoma                            |                                                                      X   |             
 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             
                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |          X                                                               |             
      Renal Tubule, Adenoma                |                         X                                                |             
      Renal Tubule, Carcinoma              |                                                    X                     |             
                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  A  +  A  +  A  +|             
 _____________________________________________________________________________________________________________________|             
 SYSTEMIC LESIONS                          |                                                                          |             
                                            __________________________________________________________________________|             
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Histiocytic Sarcoma                  |          X                                                               |             
      Lymphoma Malignant                   |                                                                          |             
 _____________________________________________________________________________________________________________________|             

                                                             Page  24                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 4| 4| 0| 5| 5| 4| 5| 6| 4| 6| 5| 4| 6| 6| 4| 5| 5| 5| 6| 5| 7| 4| 5|            |
                             DAY ON TEST   | 1| 1| 8| 6| 9| 4| 5| 6| 5| 2| 9| 8| 5| 6| 5| 6| 8| 8| 8| 5| 2| 6| 2| 6| 7|            |
                                           | 1| 6| 9| 8| 4| 5| 2| 6| 6| 9| 3| 3| 3| 3| 8| 0| 3| 0| 2| 3| 7| 2| 2| 4| 4|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 2|     A      |
    400 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  A  +  +  +  A  A  +  A  +  +  +  +  +  +  +  +  A  +  +  +  +  +  A  +|  33        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +|  40        |
                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | A  A  +  +  +  A  A  +  A  A  +  +  +  +  A  +  +  A  +  A  +  +  +  A  +|  27        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  42        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  A  +  +  +  A  A  +  +  A  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +|  35        |
                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  A  A  A  +  A  +  +  +  A  +  +  +  +  +  +  +  A  +  A  +  +  +  A  +|  31        |
                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cholangiocarcinoma                   |                   X                                      X               |          2 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Lymphoma Malignant                   |                      X                                                   |          1 |
                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +                                 |   2        |
                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Acinus, Adenoma                      |                X                          X                              |          7 |
                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Squamous Cell Papilloma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                             +            |   3        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Blood Vessel                            |                                                                          |   3        |
                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Endocardium, Schwannoma Benign       |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pheochromocytoma Malignant           |                                     X                                    |          1 |
                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Carcinoma                            |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Pars Distalis, Adenoma               | X  X                                      X  X  X        X  X     X      |         13 |
      Pars Intermedia, Adenoma             |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      C-Cell, Adenoma                      |                            X                                            X|          3 |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  25                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 4| 4| 0| 5| 5| 4| 5| 6| 4| 6| 5| 4| 6| 6| 4| 5| 5| 5| 6| 5| 7| 4| 5|            |
                             DAY ON TEST   | 1| 1| 8| 6| 9| 4| 5| 6| 5| 2| 9| 8| 5| 6| 5| 6| 8| 8| 8| 5| 2| 6| 2| 6| 7|            |
                                           | 1| 6| 9| 8| 4| 5| 2| 6| 6| 9| 3| 3| 3| 3| 8| 0| 3| 0| 2| 3| 7| 2| 2| 4| 4|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 2|     A      |
    400 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Coagulating Gland                       | +  A  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  45        |
                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Adenoma                              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Schwannoma Malignant                 |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Bilateral, Interstitial Cell, Adenoma|                                                                          |          5 |
      Interstitial Cell, Adenoma           |       X                       X                    X        X     X  X   |          7 |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node                              | +  +  +  +  +  +  +  +        +  +  +  +  +  +     +     +        +  +  +|  32        |
      Pancreatic, Histiocytic Sarcoma      |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemangioma                           |                                                                          |          1 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Lymphoma Malignant                   |                      X                                                   |          1 |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +|  46        |
      Fibroadenoma                         |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basal Cell Carcinoma                 |                                                                          |          1 |
      Keratoacanthoma                      |                                                                          |          1 |
      Subcutaneous Tissue, Fibroma         |                                                                          |          1 |
      Subcutaneous Tissue, Fibroma,        |                                                                          |            |
          Multiple                         |                                                                          |          1 |
      Subcutaneous Tissue, Fibrosarcoma    |                                                                          |          1 |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Joint, Sarcoma                       |                                                                          |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  26                                                               
NTP Experiment-Test: 55301-06                        NEOPLASMS BY INDIVIDUAL ANIMAL                               Report: PEIRPT04
Study Type: CHRONIC                                              PYRIDINE                                         Date: 10/08/97  
Route: DOSED WATER                                                                                                Time: 12:18:28  
                                                                                                                                    
 __________________________________________________________________________________________________________________________________ 
                                           | 5| 6| 4| 4| 0| 5| 5| 4| 5| 6| 4| 6| 5| 4| 6| 6| 4| 5| 5| 5| 6| 5| 7| 4| 5|            |
                             DAY ON TEST   | 1| 1| 8| 6| 9| 4| 5| 6| 5| 2| 9| 8| 5| 6| 5| 6| 8| 8| 8| 5| 2| 6| 2| 6| 7|            |
                                           | 1| 6| 9| 8| 4| 5| 2| 6| 6| 9| 3| 3| 3| 3| 8| 0| 3| 0| 2| 3| 7| 2| 2| 4| 4|            |
 _____________________________________________________________________________________________________________________|     T (*)  |
                                           | 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|     O      |
   WISTAR OUTBRED 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|     T      |
                               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| 2|     A      |
    400 PPM                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|     L      |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |
 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                       +              +   |   5        |
                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                       +                  |   4        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Carcinoma, Metastatic, Zymbal's Gland|                                  X                                       |          1 |
      Fibrosarcoma, Metastatic, Skin       |                                                                          |          1 |
      Histiocytic Sarcoma                  |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Chondroma                            |                                                    X                     |          1 |
                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Ear                                     |                                                                          |   1        |
                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                  +                                       |   1        |
                                            __________________________________________________________________________|____________|
   Zymbal's Gland                          |                      +           +                                       |   3        |
      Carcinoma                            |                      X           X                                       |          3 |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Renal Tubule, Adenoma                |                                  X                                       |          2 |
      Renal Tubule, Carcinoma              |                                                                          |          1 |
                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  A  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +|  44        |
 __________________________________________________________________________________________________________________________________ 
 SYSTEMIC LESIONS                          |                                                                          |            |
                                            __________________________________________________________________________|____________|
   Multiple Organs                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Histiocytic Sarcoma                  |                                                                          |          1 |
      Lymphoma Malignant                   |                      X                                                   |          1 |
 __________________________________________________________________________________________________________________________________ 

                         * : Total animals with tissue examined microscopically; total animals with tumor                           
                         + : Tissue examined microscopically                      M : Missing tissue                                
                         X : Lesion present                                       A : Autolysis precludes evaluation                
                         I : Insufficient tissue                              BLANK : Not examined microscopically                  

                                                             Page  27                                                               
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                                  ----------              END OF REPORT             ----------                                      
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