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TDMS Study 05172-01 Pathology Tables


                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE


NTP Experiment-Test: 05172-01                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 09/18/94
Route: DOSED WATER                                                                                                Time: 06:28:48




       Facility:  Hazleton Laboratories America, Inc.

       Chemical CAS #:  20325400

       Lock Date:  None

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All
































a  Number of animals examined microscopically at site and number of animals with lesion

                                                             Page   1

NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          70           45           75           70                                     
  Scheduled Sacrifice                                 10                                     10                                     
  Early Deaths                                                                                                                      
    Moribund                                          10           27           60           51                                     
    Dead                                               5            3            9            9                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                45           15            6                                                  
  Animals Examined Microscopically                    60           45           75           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (60)         (44)         (75)         (58)                                   
      Hemorrhage, Focal                                                          1 (1%)       1 (2%)                                
      Parasite Metazoan                                             1 (2%)                                                          
      Submucosa, Inflammation, Acute                                                          1 (2%)                                
   Intestine Large, Colon                             (60)         (44)         (75)         (59)                                   
      Parasite Metazoan                                             1 (2%)       1 (1%)       1 (2%)                                
      Descending Colon, Hemorrhage, Focal                                        1 (1%)                                             
      Muscularis, Mineralization                                                              1 (2%)                                
   Intestine Large, Rectum                            (60)         (43)         (74)         (59)                                   
      Parasite Metazoan                                                          3 (4%)       3 (5%)                                
   Liver                                              (60)         (44)         (75)         (60)                                   
      Angiectasis                                      1 (2%)                                                                       
      Angiectasis, Focal                               1 (2%)       1 (2%)                                                          
      Basophilic Focus                                44 (73%)     34 (77%)     54 (72%)     48 (80%)                               
      Clear Cell Focus                                 7 (12%)     11 (25%)     18 (24%)     15 (25%)                               
      Cyst                                                                                    1 (2%)                                
      Degeneration, Cystic                             1 (2%)       2 (5%)                    3 (5%)                                
      Degeneration, Cystic, Focal                                                1 (1%)       2 (3%)                                
      Eosinophilic Focus                               5 (8%)       7 (16%)     20 (27%)     28 (47%)                               
      Fatty Change                                     1 (2%)       1 (2%)       4 (5%)       1 (2%)                                
      Granuloma                                       10 (17%)      3 (7%)       7 (9%)       5 (8%)                                
      Hematopoietic Cell Proliferation                 1 (2%)      18 (41%)     43 (57%)     41 (68%)                               
      Hepatodiaphragmatic Nodule                       5 (8%)       6 (14%)      4 (5%)       1 (2%)                                
      Hepatodiaphragmatic Nodule, Multiple             1 (2%)                    1 (1%)                                             
      Necrosis, Coagulative                                                      1 (1%)       3 (5%)                                
      Necrosis, Focal                                                            5 (7%)       9 (15%)                               
      Necrosis, Multifocal                                          1 (2%)       1 (1%)       1 (2%)                                
      Pigmentation                                                  1 (2%)                                                          
      Regeneration, Diffuse                            6 (10%)      2 (5%)       2 (3%)       1 (2%)                                
      Regeneration, Focal                                                        1 (1%)                                             
      Regeneration, Multifocal                                      1 (2%)       2 (3%)       3 (5%)                                
      Thrombosis                                                                              1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Vacuolization Cytoplasmic, Diffuse                                         3 (4%)       1 (2%)                                
      Vacuolization Cytoplasmic, Focal                 1 (2%)       1 (2%)                    2 (3%)                                
      Vacuolization Cytoplasmic, Multifocal            2 (3%)                    1 (1%)                                             
      Bile Duct, Hyperplasia                           1 (2%)       1 (2%)       2 (3%)                                             
      Bile Duct, Inflammation, Chronic                                                        1 (2%)                                
      Centrilobular, Degeneration                      1 (2%)       1 (2%)       1 (1%)       1 (2%)                                
      Centrilobular, Degeneration, Diffuse                          2 (5%)       7 (9%)       4 (7%)                                
      Centrilobular, Necrosis                          1 (2%)       1 (2%)       1 (1%)                                             
      Centrilobular, Necrosis, Diffuse                              1 (2%)       5 (7%)       5 (8%)                                
      Kupffer Cell, Pigmentation                                                              1 (2%)                                
   Mesentery                                          (6)          (1)          (8)          (7)                                    
      Fat, Accessory Spleen                                                      1 (13%)                                            
      Fat, Necrosis                                    6 (100%)     1 (100%)     5 (63%)      5 (71%)                               
   Pancreas                                           (60)         (43)         (75)         (59)                                   
      Atrophy                                          4 (7%)       4 (9%)       4 (5%)                                             
      Hemorrhage, Focal                                                                       1 (2%)                                
   Pharynx                                            (1)          (1)          (6)          (2)                                    
      Mucosa, Palate, Hyperplasia, Focal                                         2 (33%)      1 (50%)                               
      Palate, Hyperkeratosis, Focal                                 1 (100%)                                                        
   Salivary Glands                                    (59)         (44)         (75)         (59)                                   
      Atrophy                                          1 (2%)                    2 (3%)                                             
      Inflammation, Chronic                                         1 (2%)                                                          
   Stomach, Forestomach                               (60)         (44)         (74)         (58)                                   
      Acanthosis                                                                 3 (4%)       1 (2%)                                
      Hyperkeratosis                                                             1 (1%)                                             
   Stomach, Glandular                                 (60)         (44)         (75)         (59)                                   
      Erosion, Focal                                                1 (2%)       1 (1%)       2 (3%)                                
      Erosion, Multifocal                                                        1 (1%)                                             
      Inflammation, Acute                                                                     1 (2%)                                
      Mineralization                                                                          2 (3%)                                
      Necrosis, Multifocal                                                       1 (1%)                                             
   Tongue                                             (1)          (2)          (5)          (4)                                    
      Hyperplasia, Focal                                                         2 (40%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (60)         (45)         (75)         (60)                                   
      Cardiomyopathy, Chronic                         25 (42%)     17 (38%)     21 (28%)     17 (28%)                               
      Artery, Mineralization, Multifocal                                                      1 (2%)                                
      Atrium, Thrombosis                                            1 (2%)                    1 (2%)                                
      Epicardium, Inflammation, Chronic                                                       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (60)         (45)         (75)         (60)                                   
      Congestion                                                                 1 (1%)                                             
      Degeneration, Focal                              1 (2%)       1 (2%)                                                          
      Ectasia                                                                    1 (1%)                                             
      Hematopoietic Cell Proliferation                                                        1 (2%)                                
      Hyperplasia, Focal                               5 (8%)       1 (2%)                                                          
      Hyperplasia, Multifocal                                                    1 (1%)                                             
      Hypertrophy, Focal                               2 (3%)       3 (7%)       1 (1%)       1 (2%)                                
      Hypertrophy, Multifocal                                                    1 (1%)                                             
      Infiltration Cellular, Lymphocyte                                                       1 (2%)                                
      Necrosis, Focal                                                                         1 (2%)                                
      Vacuolization Cytoplasmic, Diffuse                                         1 (1%)       3 (5%)                                
      Vacuolization Cytoplasmic, Focal                 2 (3%)                                 1 (2%)                                
   Adrenal Gland, Medulla                             (60)         (45)         (74)         (59)                                   
      Hematopoietic Cell Proliferation                                           1 (1%)       1 (2%)                                
      Hyperplasia, Focal                               5 (8%)                    1 (1%)       3 (5%)                                
      Hyperplasia, Multifocal                          1 (2%)                                                                       
   Parathyroid Gland                                  (58)         (43)         (70)         (59)                                   
      Hyperplasia                                                                             1 (2%)                                
   Pituitary Gland                                    (60)         (45)         (75)         (60)                                   
      Pigmentation                                                               1 (1%)                                             
      Pars Distalis, Angiectasis                       3 (5%)       4 (9%)       3 (4%)       1 (2%)                                
      Pars Distalis, Cyst                             14 (23%)     10 (22%)     17 (23%)     19 (32%)                               
      Pars Distalis, Hemorrhage                        1 (2%)                                                                       
      Pars Distalis, Hyperplasia                       1 (2%)                                                                       
      Pars Distalis, Hyperplasia, Diffuse              1 (2%)       2 (4%)                                                          
      Pars Distalis, Hyperplasia, Focal                5 (8%)       4 (9%)       7 (9%)       2 (3%)                                
      Pars Distalis, Hyperplasia, Multifocal           1 (2%)                    1 (1%)                                             
      Pars Distalis, Necrosis, Focal                                             1 (1%)       1 (2%)                                
      Pars Distalis, Pigmentation, Focal                                                      1 (2%)                                
      Pars Intermedia, Cyst                                                                   1 (2%)                                
   Thyroid Gland                                      (60)         (44)         (75)         (59)                                   
      C-Cell, Hyperplasia, Focal                       6 (10%)      4 (9%)       1 (1%)       3 (5%)                                
      C-Cell, Hyperplasia, Multifocal                               1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (58)         (44)         (74)         (55)                                   
      Atrophy                                          3 (5%)                    2 (3%)       2 (4%)                                
      Cyst                                                                       1 (1%)                                             
      Ectasia                                         15 (26%)     11 (25%)     11 (15%)     12 (22%)                               
      Hyperplasia, Focal                               3 (5%)       4 (9%)       7 (9%)       5 (9%)                                
      Hyperplasia, Focal, Squamous                     1 (2%)       2 (5%)                    1 (2%)                                
      Hyperplasia, Multifocal                                       2 (5%)                                                          
      Hyperplasia, Multifocal, Squamous                             1 (2%)       1 (1%)                                             
      Inflammation, Acute                                           1 (2%)                                                          
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Chronic Active                                               1 (1%)                                             
      Necrosis                                                      1 (2%)                                                          
   Ovary                                              (60)         (45)         (75)         (58)                                   
      Cyst                                             6 (10%)      7 (16%)      4 (5%)       4 (7%)                                
      Bilateral, Cyst                                  1 (2%)                                                                       
      Germinal Epithelium, Hyperplasia, Focal,                                                                                      
           Papillary                                   1 (2%)                                                                       
   Oviduct                                                         (1)                                                              
      Thrombosis                                                    1 (100%)                                                        
   Uterus                                             (60)         (45)         (75)         (59)                                   
      Cyst                                             1 (2%)                                                                       
      Fibrosis                                                                   2 (3%)                                             
      Hydrometra                                       3 (5%)       1 (2%)       4 (5%)       2 (3%)                                
      Inflammation, Acute                                           1 (2%)                                                          
      Thrombosis                                                    1 (2%)                                                          
      Bilateral, Hydrometra                                         1 (2%)                                                          
      Cervix, Cyst                                     2 (3%)                                                                       
      Cervix, Fibrosis                                11 (18%)      3 (7%)       1 (1%)                                             
      Cervix, Prolapse                                 1 (2%)                                                                       
      Endometrium, Cyst                                1 (2%)       2 (4%)       6 (8%)       3 (5%)                                
   Vagina                                             (1)                       (1)                                                 
      Thrombosis, Multiple                             1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (60)         (45)         (75)         (60)                                   
      Hyperplasia                                      5 (8%)       8 (18%)      9 (12%)     14 (23%)                               
      Hypoplasia                                       2 (3%)                                                                       
      Myelofibrosis                                    1 (2%)       1 (2%)       1 (1%)                                             
   Lymph Node                                         (60)         (45)         (75)         (60)                                   
      Axillary, Hyperplasia, Lymphoid                                                         3 (5%)                                
      Mediastinal, Congestion                                                                 1 (2%)                                
      Mediastinal, Erythrophagocytosis                              1 (2%)                                                          
      Mediastinal, Hemorrhage                                                    1 (1%)       2 (3%)                                
      Mediastinal, Hyperplasia, Lymphoid               1 (2%)                                 4 (7%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Mediastinal, Infiltration Cellular,                                                                                           
          Histiocyte                                                1 (2%)                    1 (2%)                                
      Mediastinal, Pigmentation                        1 (2%)                                                                       
      Pancreatic, Congestion                                                                  1 (2%)                                
      Pancreatic, Hyperplasia, Lymphoid                                                       2 (3%)                                
      Pancreatic, Pigmentation                         1 (2%)                    1 (1%)                                             
   Lymph Node, Mandibular                             (59)         (44)         (74)         (59)                                   
      Congestion                                                                 3 (4%)                                             
      Hemorrhage                                                                 1 (1%)       1 (2%)                                
      Hyperplasia, Lymphoid                            2 (3%)       3 (7%)       3 (4%)       4 (7%)                                
      Hyperplasia, Reticulum Cell                                   1 (2%)       1 (1%)                                             
   Lymph Node, Mesenteric                             (60)         (44)         (75)         (58)                                   
      Atrophy                                                                    1 (1%)       2 (3%)                                
      Erythrophagocytosis                                                                     1 (2%)                                
      Hemorrhage                                                                 1 (1%)                                             
      Hyperplasia, Lymphoid                                                      1 (1%)                                             
      Hyperplasia, Reticulum Cell                      2 (3%)       3 (7%)      18 (24%)     18 (31%)                               
   Spleen                                             (60)         (44)         (75)         (60)                                   
      Atrophy                                                                    1 (1%)       2 (3%)                                
      Hematopoietic Cell Proliferation                 3 (5%)      22 (50%)     50 (67%)     47 (78%)                               
      Hemorrhage, Focal                                                          1 (1%)                                             
      Hyperplasia, Reticulum Cell                                   1 (2%)                                                          
      Infarct                                                                    1 (1%)                                             
      Pigmentation                                     5 (8%)       1 (2%)       1 (1%)       2 (3%)                                
   Thymus                                             (53)         (41)         (68)         (54)                                   
      Atrophy                                                                    1 (1%)                                             
      Congestion                                                                 1 (1%)                                             
      Hemorrhage, Focal                                                          2 (3%)                                             
      Epithelial Cell, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (59)         (43)         (75)         (59)                                   
      Galactocele                                      2 (3%)       1 (2%)                    1 (2%)                                
      Duct, Ectasia                                   16 (27%)      7 (16%)     12 (16%)      5 (8%)                                
   Skin                                               (60)         (45)         (75)         (60)                                   
      Acanthosis                                                                              1 (2%)                                
      Inflammation, Chronic                                                                   1 (2%)                                
      Hair Follicle, Hyperplasia, Basal Cell,                                                                                       
          Multifocal                                                1 (2%)                                                          
      Subcutaneous Tissue, Abscess, Focal                           1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (2)          (5)          (8)          (4)                                    
      Sternum, Osteopetrosis                           2 (100%)     4 (80%)      7 (88%)      4 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (60)         (45)         (75)         (60)                                   
      Cerebrum, Compression                            8 (13%)      2 (4%)                                                          
      Cerebrum, Necrosis, Focal                                                               1 (2%)                                
      Meninges, Infiltration Cellular, Mononuclear                                                                                  
          Cell                                                                   1 (1%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (60)         (45)         (75)         (60)                                   
      Congestion                                                                              1 (2%)                                
      Foreign Body                                                                            1 (2%)                                
      Hemorrhage, Focal                                1 (2%)                                                                       
      Hyperplasia, Lymphoid                           45 (75%)     31 (69%)     60 (80%)     53 (88%)                               
      Infiltration Cellular, Histiocyte                             3 (7%)       4 (5%)      18 (30%)                               
      Inflammation, Acute, Multifocal                                                         1 (2%)                                
      Inflammation, Focal, Suppurative                                                        1 (2%)                                
      Parasite Metazoan                                                                       1 (2%)                                
      Thrombosis                                                                 1 (1%)                                             
      Alveolar Epithelium, Hyperplasia, Focal          5 (8%)       1 (2%)       5 (7%)       2 (3%)                                
      Alveolar Epithelium, Hyperplasia, Multifocal                  1 (2%)                                                          
      Alveolus, Pigmentation                                                     2 (3%)                                             
      Bronchiole, Hyperplasia, Multifocal                                                     1 (2%)                                
   Nose                                               (60)         (45)         (75)         (60)                                   
      Fungus                                                        2 (4%)                    2 (3%)                                
      Hyperkeratosis, Focal                                                                   1 (2%)                                
      Inflammation, Acute                              1 (2%)       1 (2%)       2 (3%)                                             
      Inflammation, Chronic                                                                   1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)          (3)          (5)                                                 
      Cataract                                                      2 (67%)      3 (60%)                                            
      Inflammation, Chronic Active                                               1 (20%)                                            
      Synechia                                                      1 (33%)      1 (20%)                                            
      Cornea, Necrosis                                                           1 (20%)                                            
      Retina, Degeneration                                          2 (67%)      3 (60%)                                            
   Harderian Gland                                                 (2)          (1)          (1)                                    
      Inflammation, Chronic                                         1 (50%)      1 (100%)     1 (100%)                              
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS FEMALE                   CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
   Zymbal's Gland                                     (60)         (45)         (75)         (60)                                   
      Ectasia                                         12 (20%)     21 (47%)     29 (39%)     15 (25%)                               
      Hyperplasia, Focal                                            2 (4%)       6 (8%)       5 (8%)                                
      Hyperplasia, Focal, Squamous                                  3 (7%)       7 (9%)       8 (13%)                               
      Hyperplasia, Multifocal                                                    1 (1%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (60)         (45)         (75)         (60)                                   
      Atrophy                                                                    1 (1%)                                             
      Hydronephrosis                                                             3 (4%)                                             
      Infarct, Chronic                                 1 (2%)       2 (4%)       1 (1%)                                             
      Inflammation, Chronic Active                                  1 (2%)                                                          
      Inflammation, Suppurative                                                               1 (2%)                                
      Nephropathy, Chronic                            50 (83%)     28 (62%)     38 (51%)     37 (62%)                               
      Cortex, Cyst                                                  1 (2%)                    2 (3%)                                
      Medulla, Inflammation, Acute                                  1 (2%)                                                          
      Pelvis, Dilatation                                                                      1 (2%)                                
      Renal Tubule, Degeneration, Hyaline                           2 (4%)                                                          
      Renal Tubule, Dilatation                                      1 (2%)                                                          
      Renal Tubule, Mineralization                                                            2 (3%)                                
      Renal Tubule, Necrosis, Focal                                                           1 (2%)                                
      Renal Tubule, Pigmentation                       2 (3%)                    5 (7%)       7 (12%)                               
      Renal Tubule, Vacuolization Cytoplasmic                       1 (2%)                    1 (2%)                                
      Transitional Epithelium, Hyperplasia, Focal                                1 (1%)                                             
   Ureter                                             (2)                       (2)          (1)                                    
      Dilatation                                                                 2 (100%)     1 (100%)                              
   Urinary Bladder                                    (60)         (45)         (75)         (59)                                   
      Hemorrhage                                       1 (2%)                    1 (1%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          70           45           75           70                                     
  Scheduled Sacrifice                                 10                                     10                                     
  Early Deaths                                                                                                                      
    Dead                                               9            9           25           14                                     
    Moribund                                           7           28           50           46                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                44            8                                                               
  Animals Examined Microscopically                    60           45           75           60                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (60)         (44)         (75)         (60)                                   
      Hyperkeratosis                                                1 (2%)                    1 (2%)                                
      Inflammation, Acute                                                                     1 (2%)                                
   Intestine Large, Cecum                             (60)         (42)         (72)         (58)                                   
      Congestion                                                                 1 (1%)                                             
      Mucosa, Necrosis, Focal                                       1 (2%)                                                          
      Submucosa, Edema                                              1 (2%)                                                          
   Intestine Large, Colon                             (60)         (43)         (73)         (58)                                   
      Parasite Metazoan                                                          2 (3%)       2 (3%)                                
   Intestine Large, Rectum                            (59)         (42)         (73)         (58)                                   
      Parasite Metazoan                                             1 (2%)       4 (5%)                                             
   Intestine Small, Duodenum                          (60)         (42)         (70)         (55)                                   
      Mucosa, Hyperplasia, Diffuse                                               1 (1%)                                             
   Intestine Small, Jejunum                           (59)         (41)         (69)         (56)                                   
      Congestion                                                                 1 (1%)                                             
      Necrosis, Focal                                                                         1 (2%)                                
      Mucosa, Hyperplasia, Focal                                                 1 (1%)                                             
   Liver                                              (60)         (45)         (74)         (60)                                   
      Basophilic Focus                                42 (70%)     29 (64%)     48 (65%)     49 (82%)                               
      Clear Cell Focus                                19 (32%)     11 (24%)     16 (22%)     28 (47%)                               
      Degeneration, Cystic                             7 (12%)     21 (47%)     28 (38%)     15 (25%)                               
      Degeneration, Cystic, Focal                      6 (10%)      1 (2%)       4 (5%)       4 (7%)                                
      Degeneration, Cystic, Multifocal                              1 (2%)       2 (3%)       9 (15%)                               
      Ectasia, Multifocal                                           1 (2%)       1 (1%)                                             
      Eosinophilic Focus                               6 (10%)     15 (33%)     35 (47%)     38 (63%)                               
      Fatty Change                                     2 (3%)                    4 (5%)       3 (5%)                                
      Granuloma                                        2 (3%)       2 (4%)                    3 (5%)                                
      Hematopoietic Cell Proliferation                 2 (3%)      15 (33%)     39 (53%)     41 (68%)                               
      Hepatodiaphragmatic Nodule                       4 (7%)       3 (7%)       2 (3%)       2 (3%)                                
      Hepatodiaphragmatic Nodule, Multiple                          1 (2%)                                                          
      Infarct, Chronic                                 1 (2%)       2 (4%)                                                          
      Necrosis, Coagulative                                         1 (2%)       1 (1%)       1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Necrosis, Focal                                               1 (2%)       2 (3%)       5 (8%)                                
      Necrosis, Multifocal                                                       5 (7%)       5 (8%)                                
      Regeneration, Diffuse                                         1 (2%)       8 (11%)      3 (5%)                                
      Regeneration, Focal                              4 (7%)       1 (2%)       3 (4%)       5 (8%)                                
      Regeneration, Multifocal                         1 (2%)       5 (11%)     11 (15%)     10 (17%)                               
      Thrombosis                                                    3 (7%)       3 (4%)       7 (12%)                               
      Vacuolization Cytoplasmic, Focal                                                        3 (5%)                                
      Vacuolization Cytoplasmic, Multifocal            2 (3%)       2 (4%)       7 (9%)       7 (12%)                               
      Bile Duct, Hyperplasia                          14 (23%)      2 (4%)       6 (8%)       4 (7%)                                
      Caudate Lobe, Pigmentation                                                 1 (1%)                                             
      Caudate Lobe, Regeneration                                                 1 (1%)                                             
      Centrilobular, Degeneration, Diffuse                          4 (9%)       9 (12%)     10 (17%)                               
      Centrilobular, Necrosis                          2 (3%)       3 (7%)       4 (5%)       1 (2%)                                
      Centrilobular, Necrosis, Diffuse                 2 (3%)       7 (16%)      6 (8%)       5 (8%)                                
      Centrilobular, Necrosis, Focal                                1 (2%)                                                          
      Centrilobular, Necrosis, Multifocal                           2 (4%)                                                          
      Periportal, Fibrosis                                                       1 (1%)       1 (2%)                                
      Serosa, Hemorrhage                               1 (2%)                                                                       
      Serosa, Inflammation, Acute                                                             1 (2%)                                
   Mesentery                                          (22)         (9)          (28)         (11)                                   
      Ectasia, Focal                                                             1 (4%)                                             
      Inflammation, Acute                                                                     1 (9%)                                
      Artery, Inflammation, Chronic                    1 (5%)                                                                       
      Artery, Mineralization                                        1 (11%)                                                         
      Fat, Necrosis                                   17 (77%)      8 (89%)     21 (75%)      9 (82%)                               
      Vein, Ectasia                                                              1 (4%)                                             
   Pancreas                                           (60)         (44)         (75)         (60)                                   
      Atrophy                                          9 (15%)      4 (9%)       5 (7%)       2 (3%)                                
      Degeneration                                                                            1 (2%)                                
      Acinus, Hypertrophy, Multifocal                               1 (2%)                                                          
   Pharynx                                            (1)          (4)          (7)          (7)                                    
      Palate, Hyperplasia, Focal, Squamous                                       1 (14%)                                            
      Palate, Hyperplasia, Squamous                                              1 (14%)                                            
      Palate, Necrosis                                 1 (100%)                                                                     
   Salivary Glands                                    (60)         (44)         (75)         (60)                                   
      Atrophy                                                       1 (2%)                                                          
      Interlobular, Edema                                           1 (2%)                    1 (2%)                                
      Parotid Gland, Atrophy                                        1 (2%)                                                          
   Stomach, Forestomach                               (59)         (44)         (73)         (57)                                   
      Acanthosis                                       2 (3%)                    2 (3%)       2 (4%)                                
      Acanthosis, Diffuse                                                                     1 (2%)                                
      Ulcer                                            1 (2%)                                 2 (4%)                                
      Ulcer, Multifocal                                                                       1 (2%)                                
   Stomach, Glandular                                 (58)         (44)         (72)         (58)                                   
      Erosion, Focal                                   1 (2%)                    2 (3%)                                             
      Erosion, Multifocal                                           5 (11%)      4 (6%)                                             
      Hemorrhage, Focal                                                                       1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hemorrhage, Multifocal                                                     1 (1%)                                             
      Mineralization                                                             1 (1%)                                             
      Necrosis, Focal                                                                         1 (2%)                                
      Mucosa, Muscularis, Mineralization                            1 (2%)                                                          
      Submucosa, Hemorrhage, Focal                     1 (2%)                                                                       
   Tongue                                             (2)          (4)          (6)          (10)                                   
      Hyperkeratosis, Focal                                                                   1 (10%)                               
      Necrosis, Focal                                                            1 (17%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (60)         (44)         (75)         (60)                                   
      Cardiomyopathy, Chronic                         47 (78%)     29 (66%)     58 (77%)     42 (70%)                               
      Inflammation, Acute, Multifocal                                            1 (1%)       1 (2%)                                
      Mineralization, Multifocal                       1 (2%)                                                                       
      Artery, Mineralization                                        1 (2%)                                                          
      Atrium, Thrombosis                               3 (5%)      15 (34%)     27 (36%)     23 (38%)                               
      Epicardium, Inflammation, Chronic Active,                                                                                     
           Focal                                                    1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (60)         (44)         (74)         (60)                                   
      Angiectasis, Multifocal                                                                 1 (2%)                                
      Atrophy                                                                    1 (1%)                                             
      Congestion                                                    1 (2%)                                                          
      Hyperplasia, Focal                               3 (5%)       1 (2%)       1 (1%)                                             
      Infarct, Chronic                                                                        1 (2%)                                
      Necrosis, Multifocal                                                       1 (1%)                                             
      Pigmentation                                                               1 (1%)                                             
      Vacuolization Cytoplasmic, Diffuse                                         1 (1%)       4 (7%)                                
      Vacuolization Cytoplasmic, Focal                 1 (2%)                                                                       
      Vacuolization Cytoplasmic, Multifocal            2 (3%)                                                                       
   Adrenal Gland, Medulla                             (60)         (44)         (74)         (60)                                   
      Atrophy                                                                    1 (1%)                                             
      Congestion                                                    1 (2%)                                                          
      Hyperplasia                                      2 (3%)                                                                       
      Hyperplasia, Focal                               4 (7%)       4 (9%)       8 (11%)      5 (8%)                                
      Hyperplasia, Multifocal                          1 (2%)                    4 (5%)       5 (8%)                                
      Infarct, Chronic                                                                        1 (2%)                                
      Pigmentation                                                               1 (1%)                                             
   Islets, Pancreatic                                 (60)         (44)         (75)         (60)                                   
      Hyperplasia, Focal                                                         2 (3%)                                             
   Parathyroid Gland                                  (60)         (43)         (74)         (60)                                   
      Hyperplasia                                                   4 (9%)       3 (4%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
   Pituitary Gland                                    (58)         (43)         (74)         (59)                                   
      Pigmentation                                     1 (2%)                                                                       
      Pars Distalis, Angiectasis                                                 1 (1%)                                             
      Pars Distalis, Congestion                                                  1 (1%)                                             
      Pars Distalis, Cyst                                           2 (5%)       1 (1%)       1 (2%)                                
      Pars Distalis, Ectasia, Focal                    2 (3%)                                                                       
      Pars Distalis, Hyperplasia, Focal                             1 (2%)       1 (1%)                                             
      Pars Intermedia, Cyst                                                                   1 (2%)                                
   Thyroid Gland                                      (60)         (44)         (74)         (60)                                   
      C-Cell, Hyperplasia, Focal                       6 (10%)      4 (9%)       2 (3%)       2 (3%)                                
      C-Cell, Hyperplasia, Multifocal                  1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (60)         (45)         (75)         (59)                                   
      Atypia Cellular                                                            1 (1%)                                             
   Preputial Gland                                    (60)         (43)         (73)         (59)                                   
      Atrophy                                          4 (7%)       8 (19%)     10 (14%)      7 (12%)                               
      Cyst                                                                       1 (1%)                                             
      Ectasia                                          5 (8%)      12 (28%)     25 (34%)     24 (41%)                               
      Hyperplasia                                                   1 (2%)                                                          
      Hyperplasia, Focal                               1 (2%)       2 (5%)       4 (5%)       8 (14%)                               
      Hyperplasia, Focal, Squamous                                  3 (7%)       5 (7%)       4 (7%)                                
      Hyperplasia, Multifocal, Squamous                                          1 (1%)                                             
      Hyperplasia, Squamous                            1 (2%)       1 (2%)                                                          
      Inflammation, Acute                                                        2 (3%)       1 (2%)                                
      Inflammation, Chronic                                                      1 (1%)       1 (2%)                                
      Inflammation, Chronic Active                                               2 (3%)                                             
   Prostate                                           (60)         (44)         (75)         (60)                                   
      Hyperplasia, Focal, Glandular                    5 (8%)       2 (5%)       2 (3%)       2 (3%)                                
      Hyperplasia, Glandular, Multifocal               5 (8%)       4 (9%)       3 (4%)                                             
      Inflammation, Acute                                                        2 (3%)                                             
      Inflammation, Chronic                                                      1 (1%)                                             
      Inflammation, Chronic Active                     5 (8%)       2 (5%)      11 (15%)     11 (18%)                               
   Seminal Vesicle                                    (58)         (42)         (58)         (44)                                   
      Atrophy                                                                    1 (2%)       2 (5%)                                
      Inflammation, Chronic Active                                               1 (2%)                                             
      Bilateral, Atrophy                               1 (2%)                                                                       
      Epithelium, Hyperplasia, Focal                                             1 (2%)                                             
   Testes                                             (60)         (45)         (75)         (59)                                   
      Atrophy                                          3 (5%)       4 (9%)       2 (3%)       4 (7%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Cyst                                                                       1 (1%)                                             
      Degeneration                                                               1 (1%)       2 (3%)                                
      Interstitial Cell, Hyperplasia                   2 (3%)       4 (9%)      14 (19%)     17 (29%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (60)         (43)         (74)         (60)                                   
      Hyperplasia                                      2 (3%)       3 (7%)      14 (19%)      7 (12%)                               
      Hypoplasia                                                                 1 (1%)                                             
      Myelofibrosis                                                                           3 (5%)                                
      Myelofibrosis, Focal                                          1 (2%)       2 (3%)       2 (3%)                                
      Myeloid Cell, Hyperplasia                                     1 (2%)                                                          
   Lymph Node                                         (60)         (43)         (75)         (58)                                   
      Axillary, Congestion                                          1 (2%)                                                          
      Axillary, Erythrophagocytosis                                 1 (2%)                                                          
      Axillary, Hemorrhage                                                       1 (1%)                                             
      Axillary, Hyperplasia, Lymphoid                                            1 (1%)                                             
      Bronchial, Congestion                                                                   1 (2%)                                
      Iliac, Hyperplasia, Lymphoid                                               1 (1%)                                             
      Inguinal, Hyperplasia, Lymphoid                                                         1 (2%)                                
      Inguinal, Necrosis                                                         1 (1%)                                             
      Mediastinal, Atrophy                                                       2 (3%)                                             
      Mediastinal, Congestion                                       3 (7%)       3 (4%)       1 (2%)                                
      Mediastinal, Hemorrhage                                                    2 (3%)                                             
      Mediastinal, Hyperplasia, Lymphoid                            1 (2%)       2 (3%)       3 (5%)                                
      Mediastinal, Pigmentation                                     1 (2%)       2 (3%)       1 (2%)                                
      Pancreatic, Congestion                                                                  1 (2%)                                
      Pancreatic, Hyperplasia, Lymphoid                             1 (2%)                                                          
      Pancreatic, Hyperplasia, Reticulum Cell                                                 1 (2%)                                
   Lymph Node, Mandibular                             (60)         (43)         (74)         (58)                                   
      Congestion                                                    1 (2%)       2 (3%)       1 (2%)                                
      Erythrophagocytosis                                           1 (2%)                                                          
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)       1 (1%)       6 (10%)                               
      Hyperplasia, Reticulum Cell                                                1 (1%)                                             
   Lymph Node, Mesenteric                             (59)         (42)         (73)         (56)                                   
      Congestion                                                    1 (2%)                    1 (2%)                                
      Ectasia                                          1 (2%)                                                                       
      Hyperplasia, Lymphoid                            1 (2%)       1 (2%)       2 (3%)       3 (5%)                                
      Hyperplasia, Reticulum Cell                                   3 (7%)       6 (8%)       6 (11%)                               
   Spleen                                             (60)         (42)         (74)         (59)                                   
      Angiectasis, Focal                                                                      2 (3%)                                
      Atrophy                                          3 (5%)                    4 (5%)       4 (7%)                                
      Hematopoietic Cell Proliferation                 3 (5%)      13 (31%)     43 (58%)     38 (64%)                               
      Hyperplasia, Megakaryocyte                                                              1 (2%)                                
      Hyperplasia, Reticulum Cell                      2 (3%)                    4 (5%)       7 (12%)                               
      Metaplasia                                                                              1 (2%)                                
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Necrosis                                                                   1 (1%)                                             
      Necrosis, Multifocal                                                                    1 (2%)                                
      Pigmentation, Hemosiderin                                                  1 (1%)                                             
   Thymus                                             (53)         (34)         (55)         (48)                                   
      Atrophy                                          1 (2%)                    1 (2%)                                             
      Edema                                                                      1 (2%)                                             
      Hemorrhage                                                                              1 (2%)                                
      Epithelial Cell, Hyperplasia, Focal              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (60)         (45)         (75)         (60)                                   
      Abscess                                          1 (2%)                    1 (1%)                                             
      Acanthosis, Focal                                                          1 (1%)       1 (2%)                                
      Acanthosis, Multifocal                           1 (2%)                                                                       
      Cyst Epithelial Inclusion                        2 (3%)       2 (4%)       1 (1%)                                             
      Granuloma, Focal                                                           1 (1%)                                             
      Hyperkeratosis, Focal                                         1 (2%)       2 (3%)                                             
      Inflammation, Chronic, Focal                                  1 (2%)                                                          
      Necrosis                                                      1 (2%)                                                          
      Dermis, Fibrosis                                                                        1 (2%)                                
      Dermis, Fibrosis, Focal                                                    2 (3%)       1 (2%)                                
      Hair Follicle, Hyperplasia, Basal Cell, Focal                 1 (2%)       1 (1%)       3 (5%)                                
      Prepuce, Hemorrhage                                                                     1 (2%)                                
      Subcutaneous Tissue, Edema                                    3 (7%)       3 (4%)       3 (5%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                                            (3)          (1)          (6)                                    
      Cranium, Proliferation, Focal                                              1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (60)         (44)         (75)         (60)                                   
      Cerebellum, Hemorrhage                                                                  1 (2%)                                
      Cerebrum, Hemorrhage                                                       2 (3%)                                             
      Cerebrum, Thrombosis, Multifocal                                           1 (1%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (60)         (44)         (75)         (60)                                   
      Congestion                                                    1 (2%)       1 (1%)       1 (2%)                                
      Edema                                                                      1 (1%)                                             
      Foreign Body                                     2 (3%)                                 1 (2%)                                
      Hemorrhage                                                                 1 (1%)       1 (2%)                                
      Hyperplasia, Lymphoid                           49 (82%)     29 (66%)     55 (73%)     52 (87%)                               
      Infiltration Cellular, Histiocyte                             3 (7%)      10 (13%)      6 (10%)                               
      Inflammation, Acute, Multifocal                                                         1 (2%)                                
      Inflammation, Suppurative                        1 (2%)                                                                       
      Pigmentation, Focal                                                        1 (1%)                                             
      Thrombosis                                                                              1 (2%)                                
      Thrombosis, Multiple                                          1 (2%)                    2 (3%)                                
      Alveolar Epithelium, Hyperplasia, Focal          1 (2%)       1 (2%)       6 (8%)       1 (2%)                                
      Alveolar Epithelium, Hyperplasia, Multifocal                  1 (2%)       3 (4%)       3 (5%)                                
      Artery, Mediastinum, Mineralization                           1 (2%)                                                          
      Mediastinum, Inflammation, Acute                                                        1 (2%)                                
   Nose                                               (60)         (44)         (74)         (60)                                   
      Foreign Body                                     1 (2%)                                 1 (2%)                                
      Fungus                                           4 (7%)       3 (7%)       9 (12%)      7 (12%)                               
      Hyperkeratosis                                   2 (3%)                    2 (3%)       1 (2%)                                
      Inflammation, Acute                              6 (10%)      3 (7%)       8 (11%)      4 (7%)                                
      Inflammation, Chronic                                         1 (2%)       2 (3%)       3 (5%)                                
      Necrosis, Focal                                               1 (2%)       2 (3%)       2 (3%)                                
      Necrosis, Multifocal                                                       1 (1%)                                             
      Glands, Hyperplasia                                                                     1 (2%)                                
      Mucosa, Hyperplasia                                                        1 (1%)                                             
      Nasolacrimal Duct, Inflammation, Acute                                                  1 (2%)                                
      Submucosa, Fibrosis                                                                     1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                                                       (2)                                    
      Canal, Hyperplasia, Focal, Squamous                                                     1 (50%)                               
   Eye                                                (4)          (3)          (3)          (2)                                    
      Cataract                                         1 (25%)                   2 (67%)                                            
      Degeneration                                     1 (25%)                                                                      
      Anterior Chamber, Cornea, Inflammation, Acute                 1 (33%)                                                         
      Cornea, Inflammation, Chronic                                                           1 (50%)                               
      Retina, Degeneration                             3 (75%)                   3 (100%)                                           
   Zymbal's Gland                                     (59)         (45)         (75)         (60)                                   
      Ectasia                                         42 (71%)     40 (89%)     53 (71%)     40 (67%)                               
      Ectasia, Focal                                                             1 (1%)                                             
      Hyperplasia, Diffuse                                          2 (4%)                                                          
      Hyperplasia, Focal                                            3 (7%)       2 (3%)       2 (3%)                                
      Hyperplasia, Focal, Squamous                                  4 (9%)      10 (13%)     12 (20%)                               
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   15                                                              
NTP Experiment-Test: 05172-01         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                               3,3-DIMETHOXYBENZIDINE DIHYDROCHLORIDE                          Date: 09/18/94  
Route: DOSED WATER                                                                                                Time: 06:28:48  
____________________________________________________________________________________________________________________________________
         FISCHER 344 RATS MALE                     CONTROL      80 PPM       170 PPM      330 PPM                                   
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Hyperplasia, Multifocal                          1 (2%)                                                                       
      Hyperplasia, Squamous                                                      1 (1%)                                             
      Hypertrophy, Diffuse                                          1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (60)         (44)         (74)         (60)                                   
      Abscess, Multifocal                                                                     1 (2%)                                
      Hydronephrosis                                                             1 (1%)                                             
      Infarct, Acute                                                                          1 (2%)                                
      Infarct, Chronic                                              1 (2%)                                                          
      Mineralization                                                1 (2%)                                                          
      Nephropathy, Chronic                            53 (88%)     36 (82%)     58 (78%)     52 (87%)                               
      Thrombosis, Multifocal                                                     2 (3%)                                             
      Cortex, Infarct, Acute                                                     1 (1%)                                             
      Proximal Convoluted Renal Tubule, Necrosis,                                                                                   
           Diffuse                                     1 (2%)                    1 (1%)                                             
      Renal Tubule, Degeneration                                    1 (2%)                                                          
      Renal Tubule, Mineralization                                               2 (3%)                                             
      Renal Tubule, Necrosis, Focal                                                           2 (3%)                                
      Renal Tubule, Pigmentation                       1 (2%)       1 (2%)       2 (3%)       3 (5%)                                
      Transitional Epithelium, Hyperplasia, Focal                                1 (1%)       1 (2%)                                
   Urethra                                                                                   (1)                                    
      Hyperplasia, Focal, Squamous                                                            1 (100%)                              
   Urinary Bladder                                    (60)         (44)         (75)         (59)                                   
      Edema                                            1 (2%)                                                                       
      Hemorrhage                                                                 3 (4%)                                             
      Inflammation, Acute                                                        3 (4%)                                             
      Necrosis, Diffuse                                                          2 (3%)                                             
      Necrosis, Focal                                                            1 (1%)                                             
      Mucosa, Hyperplasia                                                        2 (3%)                                             
      Serosa, Cyst                                                               1 (1%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   16                                                              
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