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https://ntp.niehs.nih.gov/go/981

TDMS Study 05092-02 Pathology Tables



                                     INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
                                                           O-NITROANISOLE


NTP Experiment-Test: 05092-02                                                                                     Report: PEIRPT03
Study Type: CHRONIC                                                                                               Date: 09/12/94
Route: DOSED FEED                                                                                                 Time: 19:16:19




       Facility:  Southern Research Institute

       Chemical CAS #:  0091-23-6

       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: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           10           50           10           50           10           
  Scheduled Sacrifice                                              10                        10                        10           
  Early Deaths                                                                                                                      
    Natural Death                                      5                         8                         7                        
    Moribund Sacrifice                                 7                        16                        10                        
  Survivors                                                                                                                         
    Terminal Sacrifice                                38                        26                        33                        
  Animals Examined Microscopically                    50           10           50           10           50           10           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (48)         (10)         (48)                      (48)                      
      Cyst                                                                                                 1 (2%)                   
      Dilatation                                       2 (4%)                                              1 (2%)                   
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Intestine Large, Cecum                             (50)         (10)         (48)                      (50)                      
      Edema                                                                      1 (2%)                                             
   Intestine Large, Colon                             (49)         (10)         (48)                      (50)                      
      Edema                                                                      1 (2%)                                             
   Intestine Large, Rectum                            (50)         (10)         (50)                      (50)                      
      Inflammation, Chronic                                                      1 (2%)                                             
   Intestine Small, Duodenum                          (50)         (10)         (49)                      (50)                      
      Cyst                                                          1 (10%)                                                         
      Mucosa, Hyperplasia                              1 (2%)                                                                       
   Intestine Small, Ileum                             (49)         (10)         (48)                      (50)                      
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Inflammation, Pyogranulomatous                                                                       1 (2%)                   
      Lymphoid Tissue, Hyperplasia                                  1 (10%)                                                         
   Intestine Small, Jejunum                           (50)         (10)         (49)                      (49)                      
      Lymphoid Tissue, Hyperplasia                                  1 (10%)                                                         
   Liver                                              (50)         (10)         (50)         (10)         (50)         (10)         
      Basophilic Focus                                 3 (6%)                                                                       
      Clear Cell Focus                                                           1 (2%)                    4 (8%)       1 (10%)     
      Cytologic Alterations                                                      1 (2%)                    1 (2%)                   
      Eosinophilic Focus                              11 (22%)                   6 (12%)      1 (10%)     21 (42%)                  
      Fibrosis, Focal                                  1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 5 (10%)                   2 (4%)                    4 (8%)                   
      Hemorrhage                                       2 (4%)                    1 (2%)                                             
      Hyperplasia, Lymphoid                            4 (8%)                    3 (6%)                   13 (26%)                  
      Infarct                                          1 (2%)                                                                       
      Inflammation, Chronic                            4 (8%)                   10 (20%)                   5 (10%)                  
      Inflammation, Chronic Active                                  7 (70%)                   4 (40%)                   4 (40%)     
      Mineralization                                                                                       1 (2%)                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    2                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Mixed Cell Focus                                                           1 (2%)                                             
      Centrilobular, Necrosis                          1 (2%)                    1 (2%)                    1 (2%)                   
      Hepatocyte, Cytologic Alterations                                          8 (16%)      1 (10%)     13 (26%)      9 (90%)     
      Hepatocyte, Vacuolization Cytoplasmic            2 (4%)                    1 (2%)       2 (20%)                               
      Kupffer Cell, Hyperplasia                        3 (6%)                    5 (10%)                   1 (2%)                   
      Kupffer Cell, Pigmentation                                                 3 (6%)                                             
      Lobules, Necrosis                                3 (6%)                    8 (16%)                   3 (6%)                   
      Periportal, Inflammation                         1 (2%)                                                                       
   Mesentery                                          (9)          (1)          (7)                       (5)                       
      Accessory Spleen                                 1 (11%)                                                                      
      Inflammation, Suppurative                                                  1 (14%)                   1 (20%)                  
      Fat, Hemorrhage                                                                                      1 (20%)                  
      Fat, Necrosis                                    6 (67%)                   2 (29%)                   1 (20%)                  
   Pancreas                                           (50)         (10)         (50)                      (50)                      
      Atrophy                                          1 (2%)       1 (10%)      3 (6%)                    2 (4%)                   
      Cyst                                             2 (4%)                    1 (2%)                    1 (2%)                   
      Cytoplasmic Alteration                           2 (4%)                    3 (6%)                    3 (6%)                   
      Focal Cellular Change                            1 (2%)                                                                       
      Hyperplasia, Lymphoid                           14 (28%)                   8 (16%)                  13 (26%)                  
   Salivary Glands                                    (49)         (10)         (50)                      (50)                      
      Hyperplasia, Lymphoid                           18 (37%)                  24 (48%)                  19 (38%)                  
   Stomach, Forestomach                               (50)         (10)         (50)                      (50)         (1)          
      Cyst                                                                       1 (2%)                    1 (2%)                   
      Diverticulum                                     1 (2%)                    3 (6%)                    1 (2%)                   
      Inflammation, Chronic                            1 (2%)                    2 (4%)                    2 (4%)                   
      Inflammation, Suppurative                        3 (6%)                    4 (8%)                    3 (6%)                   
      Mineralization                                   1 (2%)                                                                       
      Ulcer                                            1 (2%)                                                                       
      Mucosa, Hyperplasia                              7 (14%)                   6 (12%)                   7 (14%)      1 (100%)    
   Stomach, Glandular                                 (50)         (10)         (50)                      (50)                      
      Cyst                                            17 (34%)      2 (20%)     20 (40%)                  13 (26%)                  
      Dysplasia                                                                  1 (2%)                    1 (2%)                   
      Edema                                            1 (2%)                                              1 (2%)                   
      Erosion                                          2 (4%)                    4 (8%)                    2 (4%)                   
      Infiltration Cellular, Plasma Cell                                         1 (2%)                                             
      Inflammation, Acute                                           1 (10%)                                                         
      Inflammation, Chronic                            1 (2%)                    2 (4%)                                             
      Inflammation, Subacute                           1 (2%)                                                                       
      Mineralization                                                             1 (2%)                                             
      Mucosa, Hyperplasia                              1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    3                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (10)         (50)                      (50)                      
      Epicardium, Inflammation, Chronic                1 (2%)                                                                       
      Epicardium, Inflammation, Suppurative                                      1 (2%)                    1 (2%)                   
      Myocardium, Fibrosis                                                       1 (2%)                                             
      Myocardium, Inflammation, Chronic                                          2 (4%)                    3 (6%)                   
      Myocardium, Mineralization                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (10)         (50)                      (50)                      
      Accessory Adrenal Cortical Nodule                9 (18%)                   7 (14%)                   8 (16%)                  
      Basophilic Focus                                 1 (2%)                    2 (4%)                    2 (4%)                   
      Clear Cell Focus                                 1 (2%)                                                                       
      Cyst                                             3 (6%)                    1 (2%)                    2 (4%)                   
      Developmental Malformation                                                 1 (2%)                                             
      Hematopoietic Cell Proliferation                 2 (4%)                                              3 (6%)                   
      Hyperplasia, Diffuse                                                       1 (2%)                                             
      Hyperplasia, Focal                               5 (10%)      2 (20%)      6 (12%)                   6 (12%)                  
      Capsule, Hyperplasia                             5 (10%)                   2 (4%)                                             
      Subcapsular, Hyperplasia                                      6 (60%)                                                         
      X-Zone, Degeneration, Fatty                      1 (2%)                                                                       
   Adrenal Gland, Medulla                             (50)         (10)         (50)                      (50)                      
      Hyperplasia                                      3 (6%)                    4 (8%)                                             
   Islets, Pancreatic                                 (50)         (10)         (50)                      (50)                      
      Cyst                                                          1 (10%)                                                         
      Hyperplasia                                     10 (20%)      2 (20%)     12 (24%)                   7 (14%)                  
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
   Parathyroid Gland                                  (50)         (9)          (48)                      (49)                      
      Cyst                                                                       2 (4%)                                             
      Hyperplasia                                      1 (2%)                    1 (2%)                                             
   Pituitary Gland                                    (49)         (10)         (47)                      (48)         (1)          
      Pars Distalis, Angiectasis                       3 (6%)                    2 (4%)                                             
      Pars Distalis, Cyst                                                        1 (2%)                                             
      Pars Distalis, Hyperplasia                       9 (18%)                  10 (21%)                   5 (10%)                  
   Thyroid Gland                                      (50)         (9)          (50)                      (50)                      
      Degeneration, Cystic                            23 (46%)      3 (33%)     19 (38%)                  25 (50%)                  
      Inflammation, Chronic                            2 (4%)                    4 (8%)                    2 (4%)                   
      Inflammation, Suppurative                        3 (6%)                    2 (4%)                                             
      Follicle, Cyst                                                             3 (6%)                    2 (4%)                   
      Follicular Cell, Hyperplasia                     9 (18%)                   7 (14%)                   4 (8%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    4                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                                                                             (2)                       
      Bacterium                                                                                            1 (50%)                  
      Inflammation, Suppurative                                                                            1 (50%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                                               (2)                       (2)                       
      Ectasia                                                                    2 (100%)                  2 (100%)                 
      Inflammation, Chronic                                                      1 (50%)                   1 (50%)                  
      Pigmentation                                                               2 (100%)                  1 (50%)                  
   Ovary                                              (49)         (10)         (50)                      (48)                      
      Angiectasis                                     12 (24%)                  11 (22%)                   6 (13%)                  
      Cyst                                            20 (41%)                  17 (34%)                  11 (23%)                  
      Fibrosis                                                                   1 (2%)                                             
      Hemorrhage                                       1 (2%)                    2 (4%)                    1 (2%)                   
      Hyperplasia, Lymphoid                                                                                1 (2%)                   
      Inflammation, Granulomatous                      1 (2%)                                                                       
      Inflammation, Suppurative                        3 (6%)                    2 (4%)                    4 (8%)                   
      Mineralization                                                             1 (2%)                                             
      Pigmentation                                                               1 (2%)                                             
      Interstitial Cell, Hyperplasia                                                                       1 (2%)                   
   Uterus                                             (50)         (10)         (50)         (6)          (50)         (8)          
      Angiectasis                                      3 (6%)                    3 (6%)                    2 (4%)                   
      Exudate                                          8 (16%)      2 (20%)      4 (8%)       2 (33%)      6 (12%)      4 (50%)     
      Hydrometra                                       9 (18%)                  11 (22%)                   6 (12%)                  
      Hyperplasia                                                   1 (10%)                                                         
      Hyperplasia, Cystic                             48 (96%)      9 (90%)     46 (92%)      6 (100%)    48 (96%)      8 (100%)    
      Hyperplasia, Lymphoid                                                                                1 (2%)                   
      Inflammation, Chronic                                                                                1 (2%)                   
      Mineralization                                                                                       1 (2%)                   
      Necrosis                                                                                             1 (2%)                   
      Epithelium, Hyperplasia, Focal                                                          1 (17%)                               
      Mucosa, Metaplasia, Squamous                                               1 (2%)                    2 (4%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (10)         (50)                      (50)                      
      Angiectasis                                      1 (2%)                    1 (2%)                    1 (2%)                   
      Hypercellularity                                 3 (6%)                   10 (20%)                   9 (18%)                  
      Myelofibrosis                                    1 (2%)                                              1 (2%)                   
   Lymph Node                                         (50)         (10)         (50)         (1)          (50)                      
      Bronchial, Hemorrhage                                                      1 (2%)                                             
      Bronchial, Hyperplasia, Lymphoid                                                        1 (100%)                              
      Iliac, Hematopoietic Cell Proliferation                                    2 (4%)                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    5                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Iliac, Hyperplasia, Lymphoid                                               1 (2%)                                             
      Iliac, Hyperplasia, Plasma Cell                  1 (2%)                                              4 (8%)                   
      Inguinal, Hyperplasia, Lymphoid                                                                      1 (2%)                   
      Mediastinal, Hyperplasia, Lymphoid               2 (4%)                                                                       
      Mediastinal, Hyperplasia, Plasma Cell            3 (6%)                    1 (2%)                    4 (8%)                   
      Mediastinal, Inflammation, Suppurative                                                               2 (4%)                   
      Mediastinal, Necrosis                                                      1 (2%)                                             
      Pancreatic, Hematopoietic Cell Proliferation                               1 (2%)                                             
      Pancreatic, Hemorrhage                                                     1 (2%)                                             
      Pancreatic, Hyperplasia, Plasma Cell                                       1 (2%)                                             
      Renal, Hyperplasia, Lymphoid                     1 (2%)                                                                       
      Renal, Hyperplasia, Plasma Cell                  1 (2%)                                              4 (8%)                   
      Renal, Inflammation, Suppurative                 1 (2%)                                                                       
   Lymph Node, Mandibular                             (49)         (10)         (49)                      (49)                      
      Hematopoietic Cell Proliferation                 1 (2%)                                              1 (2%)                   
      Hemorrhage                                       1 (2%)                                                                       
      Hyperplasia, Lymphoid                            2 (4%)                    2 (4%)                    1 (2%)                   
      Hyperplasia, Mast Cell                           1 (2%)                                                                       
      Hyperplasia, Plasma Cell                         1 (2%)                    1 (2%)                                             
   Lymph Node, Mesenteric                             (47)         (10)         (47)                      (48)                      
      Depletion Cellular                               1 (2%)                    1 (2%)                                             
      Hematopoietic Cell Proliferation                 3 (6%)                    4 (9%)                    5 (10%)                  
      Hemorrhage                                       4 (9%)                    6 (13%)                   9 (19%)                  
      Hyperplasia, Lymphoid                            2 (4%)                                              2 (4%)                   
      Hyperplasia, Plasma Cell                         1 (2%)                                              2 (4%)                   
      Inflammation, Suppurative                                                                            1 (2%)                   
   Spleen                                             (50)         (10)         (50)         (2)          (50)         (1)          
      Congestion                                       2 (4%)                    1 (2%)                    1 (2%)                   
      Hematopoietic Cell Proliferation                14 (28%)      1 (10%)     25 (50%)                  17 (34%)                  
      Pigmentation, Hemosiderin                        9 (18%)                   4 (8%)       1 (50%)     12 (24%)      1 (100%)    
      Lymphoid Follicle, Atrophy                       1 (2%)                    1 (2%)                    1 (2%)                   
      Lymphoid Follicle, Hyperplasia                  21 (42%)                   8 (16%)      1 (50%)     11 (22%)                  
      Red Pulp, Atrophy                                1 (2%)                                              2 (4%)                   
      Red Pulp, Hyperplasia                            4 (8%)                    1 (2%)                    3 (6%)                   
   Thymus                                             (47)         (10)         (44)                      (47)                      
      Angiectasis                                      1 (2%)                    2 (5%)                    1 (2%)                   
      Cyst                                                          2 (20%)      9 (20%)                   2 (4%)                   
      Depletion Cellular                               2 (4%)                    5 (11%)                   5 (11%)                  
      Hyperplasia, Lymphoid                            2 (4%)                    1 (2%)                    1 (2%)                   
      Inflammation, Suppurative                                                  1 (2%)                                             
      Epithelial Cell, Hyperplasia                                                                         1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    6                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (10)         (50)                      (50)                      
      Hyperplasia, Cystic                              7 (14%)                   7 (14%)                   7 (14%)                  
      Hyperplasia, Lobular                             2 (4%)                    1 (2%)                    2 (4%)                   
      Inflammation, Chronic                                                                                1 (2%)                   
   Skin                                               (50)         (10)         (50)         (2)          (50)                      
      Acanthosis                                       1 (2%)                                              4 (8%)                   
      Hemorrhage                                                                              1 (50%)                               
      Inflammation, Acute                                                                     1 (50%)                               
      Inflammation, Chronic                                                                                2 (4%)                   
      Ulcer                                                                                                1 (2%)                   
      Subcutaneous Tissue, Edema                                                 1 (2%)                    1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (10)         (50)                      (50)                      
      Hyperostosis                                    18 (36%)                  12 (24%)                  13 (26%)                  
      Femur, Hyperostosis                                           1 (10%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (49)         (10)         (50)                      (50)                      
      Compression                                                                                          1 (2%)                   
      Cyst                                                                       1 (2%)                                             
      Hemorrhage                                                                 1 (2%)                                             
      Hydrocephalus                                    1 (2%)                    1 (2%)                    1 (2%)                   
      Pigmentation                                     1 (2%)                                                                       
      Cerebrum, Necrosis                                                         1 (2%)                                             
      Hippocampus, Necrosis                            1 (2%)                                                                       
      Thalamus, Mineralization                        39 (80%)      9 (90%)     45 (90%)                  44 (88%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (10)         (50)                      (50)         (1)          
      Congestion                                       3 (6%)                    1 (2%)                                             
      Edema                                                         1 (10%)                                                         
      Hemorrhage                                       2 (4%)                                              3 (6%)                   
      Hyperplasia, Lymphoid                           17 (34%)                  19 (38%)                  19 (38%)                  
      Infiltration Cellular, Histiocyte                4 (8%)                    6 (12%)                   4 (8%)                   
      Inflammation, Suppurative                        3 (6%)                    1 (2%)                    1 (2%)                   
      Leukocytosis                                                                                         1 (2%)                   
      Thrombosis                                       2 (4%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)                    3 (6%)                                             
      Bronchiole, Epithelium, Proliferation                                      3 (6%)                    5 (10%)                  
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    7                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
   Nose                                               (50)         (10)         (50)         (5)          (50)         (10)         
      Exudate                                          6 (12%)                   5 (10%)                  27 (54%)                  
      Glands, Dilatation                               9 (18%)      1 (10%)     12 (24%)                  36 (72%)      9 (90%)     
      Glands, Hyperplasia                              2 (4%)                    4 (8%)                   34 (68%)      6 (60%)     
      Mucosa, Degeneration, Hyaline                    8 (16%)      7 (70%)      7 (14%)      5 (100%)    12 (24%)      6 (60%)     
      Mucosa, Hyperplasia                              1 (2%)                                                                       
      Olfactory Epithelium, Cyst                                                                           2 (4%)                   
      Olfactory Epithelium, Metaplasia                 1 (2%)                    1 (2%)                   20 (40%)      7 (70%)     
   Trachea                                            (50)         (10)         (50)                      (50)                      
      Inflammation, Suppurative                                                  1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                       (1)                                                 
      Cataract                                         1 (100%)                                                                     
      Phthisis Bulbi                                                             1 (100%)                                           
      Cornea, Hyperplasia                              1 (100%)                                                                     
      Cornea, Inflammation, Chronic Active             1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (10)         (50)                      (50)                      
      Casts Protein                                   20 (40%)      2 (20%)     18 (36%)                  19 (38%)                  
      Cyst                                             4 (8%)                    2 (4%)                    4 (8%)                   
      Glomerulosclerosis                               2 (4%)                                              1 (2%)                   
      Hyperplasia, Lymphoid                           22 (44%)                  21 (42%)                  23 (46%)                  
      Inflammation, Chronic                            1 (2%)       6 (60%)                                                         
      Inflammation, Suppurative                        2 (4%)                                                                       
      Metaplasia, Osseous                              1 (2%)                    1 (2%)                    1 (2%)                   
      Mineralization                                  22 (44%)      1 (10%)     18 (36%)                  12 (24%)                  
      Glomerulus, Hyperplasia                                                                              1 (2%)                   
      Glomerulus, Necrosis                                                       1 (2%)                                             
      Interstitial Tissue, Pigmentation                                          1 (2%)                                             
      Renal Tubule, Atrophy                            2 (4%)                    1 (2%)                    3 (6%)                   
      Renal Tubule, Cytoplasmic Alteration             1 (2%)                                              2 (4%)                   
      Renal Tubule, Dilatation                         5 (10%)                   5 (10%)                   3 (6%)                   
      Renal Tubule, Necrosis                           1 (2%)                    3 (6%)                                             
      Renal Tubule, Pigmentation                       2 (4%)                    1 (2%)                    1 (2%)                   
      Renal Tubule, Regeneration                      33 (66%)      2 (20%)     28 (56%)                  17 (34%)                  
   Urinary Bladder                                    (50)         (10)         (50)                      (50)                      
      Edema                                            2 (4%)                    3 (6%)                                             
      Hyperplasia, Lymphoid                           27 (54%)                  24 (48%)                  25 (50%)                  
      Inflammation, Chronic                                         4 (40%)                                                         
      Transitional Epithelium, Degeneration,                                                                                        
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    8                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                15 SSAC                   15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
          Ballooning                                   1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page    9                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           10                                                               
  Scheduled Sacrifice                                              10                                                               
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 5                                                                            
  Survivors                                                                                                                         
    Terminal Sacrifice                                45                                                                            
  Animals Examined Microscopically                    50           10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (48)         (10)                                                             
      Hyperplasia, Lymphoid                            3 (6%)                                                                       
   Intestine Small, Duodenum                          (49)         (10)                                                             
      Mucosa, Hyperplasia                              3 (6%)                                                                       
   Intestine Small, Ileum                             (49)         (10)                                                             
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Liver                                              (50)         (10)                                                             
      Cytologic Alterations                            1 (2%)                                                                       
      Eosinophilic Focus                              16 (32%)      1 (10%)                                                         
      Hemorrhage                                       2 (4%)                                                                       
      Hyperplasia, Lymphoid                            6 (12%)                                                                      
      Inflammation, Chronic                           13 (26%)                                                                      
      Inflammation, Chronic Active                                  6 (60%)                                                         
      Hepatocyte, Cytologic Alterations               40 (80%)      9 (90%)                                                         
      Kupffer Cell, Pigmentation                       3 (6%)                                                                       
      Lobules, Necrosis                                2 (4%)                                                                       
   Mesentery                                          (2)                                                                           
      Hyperplasia, Lymphoid                            2 (100%)                                                                     
      Fat, Necrosis                                    1 (50%)                                                                      
   Pancreas                                           (50)         (10)                                                             
      Atrophy                                          2 (4%)                                                                       
      Cyst                                             2 (4%)                                                                       
      Hyperplasia, Lymphoid                            7 (14%)                                                                      
   Salivary Glands                                    (50)         (10)                                                             
      Atrophy                                          1 (2%)                                                                       
      Hyperplasia, Lymphoid                           20 (40%)                                                                      
      Inflammation, Chronic                                         1 (10%)                                                         
   Stomach, Forestomach                               (50)         (10)                                                             
      Diverticulum                                     2 (4%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Suppurative                        1 (2%)                                                                       
      Mucosa, Hyperplasia                              2 (4%)                                                                       
   Stomach, Glandular                                 (50)         (10)                                                             
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   10                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Cyst                                            11 (22%)      1 (10%)                                                         
      Edema                                            1 (2%)                                                                       
      Epithelium, Dilatation                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (10)                                                             
      Myocardium, Inflammation, Chronic                1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (10)                                                             
      Accessory Adrenal Cortical Nodule               14 (28%)      2 (20%)                                                         
      Cyst                                             1 (2%)                                                                       
      Developmental Malformation                       3 (6%)                                                                       
      Hyperplasia, Focal                               4 (8%)                                                                       
      Capsule, Hyperplasia                             2 (4%)                                                                       
      Subcapsular, Hyperplasia                                      2 (20%)                                                         
   Adrenal Gland, Medulla                             (50)         (10)                                                             
      Hyperplasia                                      1 (2%)                                                                       
   Islets, Pancreatic                                 (50)         (10)                                                             
      Hyperplasia                                      2 (4%)                                                                       
   Parathyroid Gland                                  (49)         (10)                                                             
      Cyst                                             2 (4%)                                                                       
      Ectopic Thymus                                   2 (4%)                                                                       
      Hyperplasia                                      1 (2%)                                                                       
      Infiltration Cellular, Histiocyte                             1 (10%)                                                         
      Pigmentation                                                  1 (10%)                                                         
   Pituitary Gland                                    (48)         (10)                                                             
      Pars Distalis, Cyst                              1 (2%)                                                                       
      Pars Intermedia, Cyst                            1 (2%)                                                                       
   Thyroid Gland                                      (50)         (10)                                                             
      Degeneration, Cystic                            28 (56%)      1 (10%)                                                         
      Inflammation, Chronic                            5 (10%)                                                                      
      Follicular Cell, Hyperplasia                     1 (2%)       1 (10%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   11                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (50)         (10)                                                             
      Angiectasis                                     12 (24%)      1 (10%)                                                         
      Cyst                                            10 (20%)                                                                      
      Hemorrhage                                       2 (4%)                                                                       
      Metaplasia, Osseous                              1 (2%)                                                                       
      Thrombosis                                       1 (2%)                                                                       
      Corpus Luteum, Hyperplasia                       1 (2%)                                                                       
      Granulosa Cell, Hyperplasia                      1 (2%)                                                                       
      Thecal Cell, Hyperplasia                         1 (2%)                                                                       
   Uterus                                             (50)         (10)                                                             
      Angiectasis                                      1 (2%)                                                                       
      Exudate                                          2 (4%)       3 (30%)                                                         
      Hydrometra                                      15 (30%)                                                                      
      Hyperplasia, Cystic                             47 (94%)      5 (50%)                                                         
      Mucosa, Dysplasia                                2 (4%)                                                                       
      Mucosa, Metaplasia, Squamous                     4 (8%)                                                                       
      Myometrium, Hyperplasia                          2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (10)                                                             
      Hypercellularity                                 2 (4%)                                                                       
      Myelofibrosis                                    1 (2%)                                                                       
   Lymph Node, Mesenteric                             (48)         (10)                                                             
      Hemorrhage                                       5 (10%)                                                                      
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
   Spleen                                             (50)         (10)                                                             
      Congestion                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 4 (8%)                                                                       
      Pigmentation, Hemosiderin                        1 (2%)                                                                       
      Lymphoid Follicle, Hyperplasia                   5 (10%)                                                                      
   Thymus                                             (49)         (10)                                                             
      Cyst                                             3 (6%)       2 (20%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (10)                                                             
      Hyperplasia, Cystic                              2 (4%)                                                                       
      Hyperplasia, Lobular                             6 (12%)                                                                      
   Skin                                               (50)         (10)                                                             
      Acanthosis                                       1 (2%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   12                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (10)                                                             
      Hyperostosis                                    11 (22%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (10)                                                             
      Cyst                                             2 (4%)                                                                       
      Thalamus, Mineralization                        43 (86%)      7 (70%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (10)                                                             
      Hemorrhage                                       3 (6%)                                                                       
      Hyperplasia, Lymphoid                           20 (40%)                                                                      
      Inflammation, Chronic                            2 (4%)                                                                       
      Alveolar Epithelium, Hyperplasia                 1 (2%)                                                                       
      Bronchiole, Epithelium, Proliferation            4 (8%)                                                                       
      Mediastinum, Ectopic Tissue                                   1 (10%)                                                         
   Nose                                               (50)         (10)                                                             
      Exudate                                         49 (98%)      3 (30%)                                                         
      Glands, Dilatation                              49 (98%)     10 (100%)                                                        
      Glands, Hyperplasia                             50 (100%)    10 (100%)                                                        
      Mucosa, Degeneration, Hyaline                   45 (90%)     10 (100%)                                                        
      Olfactory Epithelium, Cyst                       6 (12%)                                                                      
      Olfactory Epithelium, Metaplasia                49 (98%)     10 (100%)                                                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (10)                                                             
      Casts Protein                                   30 (60%)      4 (40%)                                                         
      Fibrosis                                         1 (2%)                                                                       
      Hyperplasia, Lymphoid                           14 (28%)                                                                      
      Inflammation, Chronic                                         4 (40%)                                                         
      Metaplasia, Osseous                              6 (12%)                                                                      
      Mineralization                                   9 (18%)      3 (30%)                                                         
      Renal Tubule, Regeneration                      12 (24%)      1 (10%)                                                         
   Urinary Bladder                                    (50)         (10)                                                             
      Edema                                            1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   13                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE FEMALE                        0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Hyperplasia, Lymphoid                           23 (46%)                                                                      
      Inflammation, Chronic                                         1 (10%)                                                         
      Inflammation, Granulomatous                      1 (2%)                                                                       
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   14                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           10           50           10           50           10           
  Scheduled Sacrifice                                              10                        10                         9           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                14                         5                         8                        
    Natural Death                                      1                         2                         3                        
  Survivors                                                                                                                         
    Terminal Sacrifice                                35                        43                        39                        
  Other                                                                                                                 1           
  Animals Examined Microscopically                    50           10           50           10           50            9           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (49)         (9)          (45)                      (47)                      
      Dilatation                                       1 (2%)                    1 (2%)                                             
   Intestine Large, Cecum                             (49)         (10)         (49)                      (49)                      
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
   Intestine Small, Duodenum                          (50)         (10)         (48)                      (49)                      
      Inflammation, Chronic                                                                                1 (2%)                   
      Metaplasia, Squamous                                                       1 (2%)                                             
   Intestine Small, Ileum                             (49)         (10)         (48)                      (47)                      
      Hyperplasia, Lymphoid                                                                                1 (2%)                   
   Liver                                              (50)         (10)         (50)         (10)         (50)         (9)          
      Angiectasis                                      1 (2%)                                                                       
      Basophilic Focus                                 3 (6%)       1 (10%)      1 (2%)                    1 (2%)                   
      Clear Cell Focus                                 9 (18%)                   7 (14%)      1 (10%)      9 (18%)                  
      Eosinophilic Focus                               1 (2%)                   15 (30%)                  16 (32%)                  
      Hematopoietic Cell Proliferation                 1 (2%)                                              1 (2%)                   
      Hemorrhage                                       1 (2%)                    4 (8%)                   20 (40%)                  
      Infiltration Cellular, Mixed Cell                                                                    1 (2%)                   
      Inflammation, Chronic                            1 (2%)                    3 (6%)                    1 (2%)                   
      Inflammation, Chronic Active                                                            2 (20%)                   5 (56%)     
      Mixed Cell Focus                                 1 (2%)                    3 (6%)                                             
      Regeneration, Focal                                                        1 (2%)                                             
      Centrilobular, Necrosis                          1 (2%)                    1 (2%)                                             
      Hepatocyte, Cytologic Alterations                                         44 (88%)      7 (70%)     49 (98%)      9 (100%)    
      Hepatocyte, Cytomegaly                           1 (2%)                                                                       
      Hepatocyte, Vacuolization Cytoplasmic            6 (12%)      4 (40%)      7 (14%)      2 (20%)                   3 (33%)     
      Kupffer Cell, Hyperplasia                        2 (4%)                                                                       
      Kupffer Cell, Pigmentation                                                                           3 (6%)                   
      Lobules, Necrosis                                3 (6%)                   13 (26%)                  27 (54%)      2 (22%)     
      Oval Cell, Hyperplasia                                                     1 (2%)                                             
   Mesentery                                          (4)          (2)          (2)                       (4)                       
      Hemorrhage                                                                                           1 (25%)                  
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   15                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Pyogranulomatous                                             1 (50%)                                            
      Fat, Inflammation, Chronic                                    1 (50%)                                                         
      Fat, Necrosis                                    2 (50%)      1 (50%)      1 (50%)                   1 (25%)                  
   Pancreas                                           (50)         (10)         (49)                      (49)                      
      Atrophy                                          1 (2%)                                                                       
      Focal Cellular Change                            1 (2%)                                                                       
      Hyperplasia, Focal                               1 (2%)                                                                       
      Hyperplasia, Lymphoid                            2 (4%)                                              3 (6%)                   
      Inflammation, Chronic                                         1 (10%)                                                         
      Duct, Hyperplasia                                                          1 (2%)                                             
   Salivary Glands                                    (50)         (10)         (50)                      (50)                      
      Hyperplasia, Lymphoid                           16 (32%)                  21 (42%)                  20 (40%)                  
      Inflammation, Chronic                            1 (2%)       1 (10%)                                                         
   Stomach, Forestomach                               (50)         (10)         (50)                      (50)                      
      Cyst                                             2 (4%)                                                                       
      Diverticulum                                     4 (8%)                    1 (2%)                    1 (2%)                   
      Erosion                                          1 (2%)                                                                       
      Inflammation, Chronic                            2 (4%)                                                                       
      Inflammation, Suppurative                                                  2 (4%)                                             
      Mucosa, Hyperplasia                              6 (12%)                   2 (4%)                                             
   Stomach, Glandular                                 (50)         (10)         (50)                      (49)                      
      Cyst                                             7 (14%)      1 (10%)     15 (30%)                  11 (22%)                  
      Dysplasia                                                                  1 (2%)                    1 (2%)                   
      Erosion                                          1 (2%)                                                                       
      Hemorrhage                                                                                           1 (2%)                   
      Inflammation, Chronic                                                                                1 (2%)                   
      Inflammation, Subacute                                                                               1 (2%)                   
      Mucosa, Hyperplasia                                                                                  1 (2%)                   
   Tooth                                              (11)                      (20)                      (12)                      
      Dysplasia                                       10 (91%)                  18 (90%)                  12 (100%)                 
      Inflammation, Suppurative                        1 (9%)                    2 (10%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (10)         (50)                      (50)                      
      Thrombosis                                       1 (2%)                    2 (4%)                                             
      Artery, Inflammation, Chronic Active                                       1 (2%)                                             
      Myocardium, Degeneration                         2 (4%)                                                                       
      Myocardium, Inflammation, Chronic                2 (4%)       1 (10%)      2 (4%)                    1 (2%)                   
      Myocardium, Mineralization                       2 (4%)                                              1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   16                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (50)         (10)         (50)                      (50)                      
      Accessory Adrenal Cortical Nodule                8 (16%)                   1 (2%)                    5 (10%)                  
      Angiectasis                                                                                          1 (2%)                   
      Basophilic Focus                                                           1 (2%)                                             
      Clear Cell Focus                                 1 (2%)                    3 (6%)                    6 (12%)                  
      Developmental Malformation                                                                           2 (4%)                   
      Hyperplasia, Focal                              24 (48%)                  21 (42%)                  23 (46%)                  
      Hypertrophy, Focal                                            1 (10%)                                                         
      Capsule, Hyperplasia                             6 (12%)                   6 (12%)                   5 (10%)                  
      Subcapsular, Hyperplasia                                      4 (40%)                                                         
   Adrenal Gland, Medulla                             (50)         (10)         (49)                      (50)                      
      Hyperplasia                                                                1 (2%)                                             
   Islets, Pancreatic                                 (50)         (10)         (49)                      (49)                      
      Hyperplasia                                     21 (42%)      3 (30%)     20 (41%)                   9 (18%)                  
   Parathyroid Gland                                  (50)         (10)         (49)                      (50)                      
      Cyst                                             2 (4%)       2 (20%)      3 (6%)                    2 (4%)                   
      Hyperplasia                                                                                          1 (2%)                   
      Pigmentation                                                                                         1 (2%)                   
   Pituitary Gland                                    (47)         (8)          (46)                      (49)                      
      Pars Distalis, Cyst                              1 (2%)                    4 (9%)                    7 (14%)                  
      Pars Distalis, Hyperplasia                                                 1 (2%)                    1 (2%)                   
   Thyroid Gland                                      (49)         (10)         (49)                      (50)                      
      Degeneration, Cystic                            12 (24%)      1 (10%)     11 (22%)                   9 (18%)                  
      Hemorrhage                                       1 (2%)                                                                       
      Inflammation, Chronic                                                                                1 (2%)                   
      Inflammation, Suppurative                        1 (2%)                                                                       
      Follicle, Dilatation                                          1 (10%)                                                         
      Follicular Cell, Hyperplasia                     3 (6%)                    6 (12%)                   6 (12%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                  (4)                       (1)                                                 
      Dilatation                                       2 (50%)                                                                      
   Epididymis                                         (50)         (10)         (50)                      (50)                      
      Atypia Cellular                                  1 (2%)                                                                       
      Fibrosis                                                                                             3 (6%)                   
      Granuloma Sperm                                                            1 (2%)                    1 (2%)                   
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Inflammation, Chronic                            1 (2%)                                              5 (10%)                  
   Preputial Gland                                    (24)         (3)          (24)         (1)          (25)         (2)          
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   17                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Atrophy                                                       2 (67%)                   1 (100%)                  1 (50%)     
      Ectasia                                         18 (75%)      3 (100%)    20 (83%)      1 (100%)    24 (96%)      2 (100%)    
      Fibrosis                                                                                             1 (4%)                   
      Inflammation, Chronic                           13 (54%)      2 (67%)      7 (29%)                  13 (52%)      1 (50%)     
      Inflammation, Suppurative                        6 (25%)                   4 (17%)                   4 (16%)                  
   Prostate                                           (50)         (10)         (50)                      (50)                      
      Inflammation, Suppurative                        1 (2%)                                                                       
   Seminal Vesicle                                    (50)         (10)         (50)                      (50)                      
      Dilatation                                       6 (12%)                   3 (6%)                    1 (2%)                   
   Testes                                             (50)         (10)         (50)                      (50)                      
      Granuloma Sperm                                                                                      1 (2%)                   
      Hypospermia                                      2 (4%)                    1 (2%)                                             
      Mineralization                                                             1 (2%)                    2 (4%)                   
      Interstitial Cell, Hyperplasia                                             2 (4%)                                             
      Seminiferous Tubule, Atrophy                     3 (6%)                    1 (2%)                    4 (8%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (10)         (50)                      (50)                      
      Angiectasis                                                                2 (4%)                                             
      Hypercellularity                                 1 (2%)                   10 (20%)                   6 (12%)                  
   Lymph Node                                         (50)         (10)         (50)         (1)          (50)         (1)          
      Inguinal, Hyperplasia, Lymphoid                  2 (4%)                    1 (2%)                                             
      Inguinal, Pigmentation                           1 (2%)                                              1 (2%)                   
      Mediastinal, Hemorrhage                                                                              1 (2%)                   
      Mediastinal, Inflammation, Suppurative                                     1 (2%)                                             
      Mediastinal, Inflammation, Pyogranulomatous                                1 (2%)                                             
      Pancreatic, Hemorrhage                           1 (2%)                    1 (2%)                                             
   Lymph Node, Mandibular                             (48)         (10)         (49)                      (49)                      
      Hematopoietic Cell Proliferation                                           1 (2%)                                             
      Hemorrhage                                                    1 (10%)                                                         
      Hyperplasia, Lymphoid                                                      1 (2%)                                             
      Infiltration Cellular, Mast Cell                                                                     1 (2%)                   
   Lymph Node, Mesenteric                             (47)         (10)         (49)         (1)          (46)         (1)          
      Hematopoietic Cell Proliferation                 4 (9%)                   16 (33%)                   6 (13%)                  
      Hemorrhage                                      19 (40%)      1 (10%)     23 (47%)                  21 (46%)      1 (100%)    
      Hyperplasia, Histiocytic                         1 (2%)                    2 (4%)                                             
      Hyperplasia, Lymphoid                            4 (9%)                    4 (8%)                    4 (9%)                   
      Hyperplasia, Reticulum Cell                                                1 (2%)                                             
      Infiltration Cellular, Mast Cell                                           2 (4%)                    1 (2%)                   
   Spleen                                             (50)         (10)         (50)                      (49)                      
      Congestion                                       1 (2%)                    3 (6%)                                             
      Hematopoietic Cell Proliferation                10 (20%)                  12 (24%)                  10 (20%)                  
      Pigmentation, Hemosiderin                                                  1 (2%)                                             
      Lymphoid Follicle, Atrophy                                                                           1 (2%)                   
      Lymphoid Follicle, Hyperplasia                   3 (6%)                    7 (14%)                   4 (8%)                   
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   18                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Red Pulp, Atrophy                                1 (2%)                    1 (2%)                                             
      Red Pulp, Hyperplasia                            2 (4%)                                                                       
   Thymus                                             (47)         (10)         (47)                      (45)                      
      Cyst                                             8 (17%)      3 (30%)      7 (15%)                   6 (13%)                  
      Depletion Cellular                                                         1 (2%)                    1 (2%)                   
      Epithelial Cell, Hyperplasia                                                                         1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (10)         (50)                      (50)         (1)          
      Acanthosis                                       4 (8%)                    1 (2%)                    4 (8%)                   
      Inflammation, Acute                                                                                  1 (2%)                   
      Inflammation, Chronic                            1 (2%)                    2 (4%)                    1 (2%)                   
      Inflammation, Suppurative                        2 (4%)                                                                       
      Subcutaneous Tissue, Edema                       1 (2%)                                              1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (10)         (50)                      (50)                      
      Hyperostosis                                                               1 (2%)                    1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (10)         (50)                      (50)                      
      Cyst                                                                       1 (2%)                                             
      Inflammation, Chronic                            1 (2%)                                                                       
      Thalamus, Mineralization                        41 (82%)      8 (80%)     43 (86%)                  44 (88%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (10)         (50)         (4)          (50)                      
      Congestion                                       1 (2%)                                                                       
      Hemorrhage                                       2 (4%)       1 (10%)      1 (2%)                    2 (4%)                   
      Hyperplasia, Lymphoid                                                      5 (10%)                   6 (12%)                  
      Infiltration Cellular, Histiocyte                5 (10%)                   5 (10%)      1 (25%)      1 (2%)                   
      Inflammation, Chronic                            2 (4%)                    1 (2%)                    1 (2%)                   
      Inflammation, Suppurative                                                  3 (6%)                                             
      Thrombosis                                                                                           1 (2%)                   
      Alveolar Epithelium, Hyperplasia                 5 (10%)                   4 (8%)                    2 (4%)                   
      Bronchiole, Epithelium, Proliferation                                      2 (4%)                   13 (26%)                  
   Nose                                               (50)         (10)         (50)                      (50)         (2)          
      Exudate                                          4 (8%)                    4 (8%)                    6 (12%)                  
      Glands, Dilatation                               3 (6%)       2 (20%)      6 (12%)                  12 (24%)      2 (100%)    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   19                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.0%         0.0%         0.0666%      0.0666%      0.200%       0.200%          
                                                                 15 SSAC                  15 SSAC                   15 SSAC         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Glands, Hyperplasia                              1 (2%)                    2 (4%)                   12 (24%)                  
      Olfactory Epithelium, Metaplasia                                                                     7 (14%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (3)                                                                           
      Cataract                                         1 (33%)                                                                      
      Cornea, Hyperplasia                              2 (67%)                                                                      
      Cornea, Inflammation, Chronic Active             2 (67%)                                                                      
      Cornea, Mineralization                           1 (33%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (10)         (50)                      (50)                      
      Casts Protein                                   12 (24%)                  14 (28%)                  18 (36%)                  
      Cyst                                            27 (54%)      1 (10%)     30 (60%)                  16 (32%)                  
      Fibrosis                                                                                             1 (2%)                   
      Glomerulosclerosis                               2 (4%)                    1 (2%)                    1 (2%)                   
      Hydronephrosis                                   6 (12%)                                                                      
      Hyperplasia, Lymphoid                           20 (40%)                  16 (32%)                  25 (50%)                  
      Inflammation, Chronic                            1 (2%)       2 (20%)                                1 (2%)                   
      Inflammation, Suppurative                        1 (2%)                                                                       
      Metaplasia, Osseous                              2 (4%)                                              3 (6%)                   
      Mineralization                                  41 (82%)      4 (40%)     48 (96%)                  50 (100%)                 
      Pelvis, Transitional Epithelium, Hyperplasia     1 (2%)                                                                       
      Renal Tubule, Atrophy                                                      1 (2%)                                             
      Renal Tubule, Cytoplasmic Alteration                                                                 1 (2%)                   
      Renal Tubule, Dilatation                         3 (6%)                                                                       
      Renal Tubule, Hyperplasia                                                  1 (2%)                    2 (4%)                   
      Renal Tubule, Pigmentation                                                                           5 (10%)                  
      Renal Tubule, Regeneration                      48 (96%)     10 (100%)    46 (92%)                  48 (96%)                  
      Renal Tubule, Vacuolization Cytoplasmic                                                              1 (2%)                   
   Urinary Bladder                                    (50)         (10)         (50)                      (49)                      
      Dilatation                                       3 (6%)                    1 (2%)                                             
      Edema                                                                                                1 (2%)                   
      Hyperplasia, Lymphoid                            1 (2%)                    4 (8%)                    5 (10%)                  
      Inflammation, Chronic                                         1 (10%)                                                         
      Mucosa, Hyperplasia                                                                                  1 (2%)                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   20                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially In Study                          50           10                                                               
  Scheduled Sacrifice                                              10                                                               
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                 7                                                                            
    Natural Death                                      3                                                                            
  Survivors                                                                                                                         
    Terminal Sacrifice                                40                                                                            
  Animals Examined Microscopically                    50           10                                                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Cecum                             (49)         (10)                                                             
      Edema                                            1 (2%)                                                                       
   Intestine Small, Duodenum                          (50)         (9)                                                              
      Mucosa, Hyperplasia                              3 (6%)                                                                       
   Intestine Small, Ileum                             (49)         (10)                                                             
      Hyperplasia, Lymphoid                            2 (4%)                                                                       
   Liver                                              (50)         (10)                                                             
      Angiectasis                                      1 (2%)                                                                       
      Clear Cell Focus                                 2 (4%)                                                                       
      Eosinophilic Focus                              13 (26%)      1 (10%)                                                         
      Hemorrhage                                      28 (56%)                                                                      
      Inflammation, Chronic                            1 (2%)                                                                       
      Inflammation, Chronic Active                                  3 (30%)                                                         
      Hepatocyte, Cytologic Alterations               49 (98%)     10 (100%)                                                        
      Kupffer Cell, Pigmentation                      16 (32%)                                                                      
      Lobules, Necrosis                               34 (68%)      4 (40%)                                                         
      Oval Cell, Hyperplasia                           1 (2%)                                                                       
   Pancreas                                           (50)         (10)                                                             
      Atrophy                                                       1 (10%)                                                         
      Hyperplasia, Lymphoid                            5 (10%)                                                                      
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
      Acinar Cell, Vacuolization Cytoplasmic           1 (2%)                                                                       
   Salivary Glands                                    (50)         (10)                                                             
      Hyperplasia, Lymphoid                           10 (20%)                                                                      
      Acinar Cell, Vacuolization Cytoplasmic           1 (2%)                                                                       
   Stomach, Forestomach                               (50)         (10)                                                             
      Cyst                                             1 (2%)                                                                       
      Diverticulum                                     1 (2%)                                                                       
      Erosion                                          1 (2%)                                                                       
      Mucosa, Hyperplasia                              4 (8%)                                                                       
   Stomach, Glandular                                 (50)         (10)                                                             
      Cyst                                             8 (16%)                                                                      
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   21                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Erosion                                          1 (2%)                                                                       
      Inflammation, Chronic                            1 (2%)                                                                       
   Tooth                                              (3)                                                                           
      Dysplasia                                        3 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (10)                                                             
      Myocardium, Inflammation, Chronic                1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Gland, Cortex                              (48)         (10)                                                             
      Accessory Adrenal Cortical Nodule                9 (19%)      1 (10%)                                                         
      Hyperplasia, Diffuse                             1 (2%)                                                                       
      Hyperplasia, Focal                              21 (44%)                                                                      
      Hypertrophy, Focal                                            1 (10%)                                                         
      Infiltration Cellular, Mononuclear Cell          1 (2%)                                                                       
      Capsule, Hyperplasia                             4 (8%)                                                                       
      Subcapsular, Hyperplasia                                      1 (10%)                                                         
   Adrenal Gland, Medulla                             (48)         (10)                                                             
      Hyperplasia                                      2 (4%)                                                                       
   Islets, Pancreatic                                 (50)         (10)                                                             
      Hyperplasia                                      2 (4%)                                                                       
   Parathyroid Gland                                  (48)         (10)                                                             
      Cyst                                             3 (6%)       1 (10%)                                                         
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
   Pituitary Gland                                    (48)         (9)                                                              
      Pars Distalis, Cyst                              1 (2%)                                                                       
      Pars Intermedia, Cytoplasmic Alteration          1 (2%)                                                                       
   Thyroid Gland                                      (50)         (10)                                                             
      Degeneration, Cystic                             6 (12%)      1 (10%)                                                         
      Follicular Cell, Hyperplasia                     1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   22                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (10)                                                             
      Atypia Cellular                                  1 (2%)                                                                       
      Thrombosis                                       1 (2%)                                                                       
   Preputial Gland                                    (10)                                                                          
      Ectasia                                         10 (100%)                                                                     
      Inflammation, Chronic                            4 (40%)                                                                      
      Inflammation, Suppurative                        1 (10%)                                                                      
   Testes                                             (50)         (10)                                                             
      Hypospermia                                      1 (2%)                                                                       
      Mineralization                                   2 (4%)                                                                       
      Interstitial Cell, Hyperplasia                   1 (2%)                                                                       
      Seminiferous Tubule, Atrophy                     2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (10)                                                             
      Angiectasis                                      1 (2%)                                                                       
      Hypercellularity                                 7 (14%)                                                                      
   Lymph Node                                         (50)         (10)                                                             
      Inguinal, Hyperplasia, Lymphoid                  1 (2%)                                                                       
   Lymph Node, Mesenteric                             (50)         (10)                                                             
      Hematopoietic Cell Proliferation                 3 (6%)                                                                       
      Hemorrhage                                      14 (28%)                                                                      
      Hyperplasia, Lymphoid                            7 (14%)                                                                      
   Spleen                                             (48)         (10)                                                             
      Angiectasis                                      3 (6%)                                                                       
      Congestion                                       1 (2%)                                                                       
      Hematopoietic Cell Proliferation                 7 (15%)                                                                      
      Lymphoid Follicle, Atrophy                       1 (2%)                                                                       
      Lymphoid Follicle, Hyperplasia                   2 (4%)                                                                       
      Red Pulp, Atrophy                                1 (2%)                                                                       
   Thymus                                             (48)         (10)                                                             
      Cyst                                             6 (13%)      1 (10%)                                                         
      Depletion Cellular                               2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (50)         (10)                                                             
      Acanthosis                                       1 (2%)                                                                       
      Hair Follicle, Atrophy                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   23                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (10)                                                             
      Pigmentation                                     2 (4%)                                                                       
      Thalamus, Mineralization                        40 (80%)      6 (60%)                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (10)                                                             
      Congestion                                       1 (2%)                                                                       
      Hemorrhage                                       6 (12%)                                                                      
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Infiltration Cellular, Megakaryocyte             1 (2%)                                                                       
      Infiltration Cellular, Histiocyte                1 (2%)                                                                       
      Inflammation, Chronic                            2 (4%)                                                                       
      Alveolar Epithelium, Hyperplasia                 2 (4%)                                                                       
      Bronchiole, Epithelium, Proliferation           14 (28%)                                                                      
   Nose                                               (50)         (10)                                                             
      Exudate                                         49 (98%)      1 (10%)                                                         
      Glands, Dilatation                              49 (98%)     10 (100%)                                                        
      Glands, Hyperplasia                             49 (98%)     10 (100%)                                                        
      Olfactory Epithelium, Cyst                      18 (36%)                                                                      
      Olfactory Epithelium, Metaplasia                46 (92%)     10 (100%)                                                        
      Olfactory Epithelium, Necrosis                   1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (10)                                                             
      Casts Protein                                    5 (10%)                                                                      
      Cyst                                             4 (8%)       1 (10%)                                                         
      Fibrosis                                         1 (2%)                                                                       
      Hyperplasia, Lymphoid                            8 (16%)                                                                      
      Inflammation, Chronic                                         1 (10%)                                                         
      Mineralization                                  36 (72%)      2 (20%)                                                         
      Renal Tubule, Pigmentation                       1 (2%)                                                                       
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   24                                                              
NTP Experiment-Test: 05092-02         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           O-NITROANISOLE                                      Date: 09/12/94  
Route: DOSED FEED                                                                                                 Time: 19:16:19  
____________________________________________________________________________________________________________________________________
         B6C3F1 MICE MALE                          0.600%       0.600%                                                              
                                                                15 SSAC                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Renal Tubule, Regeneration                      32 (64%)      5 (50%)                                                         
   Urinary Bladder                                    (50)         (10)                                                             
      Hyperplasia, Lymphoid                            5 (10%)                                                                      
      Inflammation, Chronic                                         1 (10%)                                                         
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                             Page   25                                                              
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------