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TDMS Study 05217-03 Pathology Tables

NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96
Route: DOSED FEED                                                                                                 Time: 06:47:04




       Facility:  Southern Research Institute

       Chemical CAS #:  1948-33-0

       Lock Date:  05/26/93

       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: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          70           70           70           70           70                        

  Scheduled Sacrifice                                 10           10           10           10           10                        
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                40           31           41           33           36                        
    Natural Death                                     10            7            8            9            7                        
  Survivors                                                                                                                         
    Terminal Sacrifice                                10           22           11           16           17                        
  Other                                                                                       2                                     

  Animals Examined Microscopically                    70           70           70           68           70                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (68)         (69)         (70)         (67)         (70)                      
      Inflammation, Subacute                                        1 (1%)                                                          
      Epithelium, Hyperplasia                                                    1 (1%)                                             
   Intestine Large, Colon                             (70)         (70)         (69)         (66)         (69)                      
      Edema                                                                                                1 (1%)                   
      Parasite Metazoan                                6 (9%)       3 (4%)       4 (6%)       4 (6%)       5 (7%)                   
      Ulcer                                                                                                1 (1%)                   
   Intestine Large, Rectum                            (69)         (70)         (69)         (67)         (69)                      
      Edema                                            1 (1%)                                                                       
      Parasite Metazoan                                2 (3%)                    2 (3%)       6 (9%)       9 (13%)                  
   Intestine Large, Cecum                             (70)         (70)         (70)         (67)         (70)                      
      Edema                                                         1 (1%)       2 (3%)       1 (1%)       2 (3%)                   
      Parasite Metazoan                                2 (3%)       2 (3%)       1 (1%)       3 (4%)       1 (1%)                   
   Intestine Small, Duodenum                          (69)         (70)         (70)         (67)         (70)                      
      Erosion                                                                    1 (1%)                                             
      Epithelium, Hyperplasia                                                    1 (1%)       1 (1%)                                
   Intestine Small, Ileum                             (70)         (70)         (68)         (67)         (68)                      
      Inflammation, Chronic Active                                                            1 (1%)                                
      Epithelium, Hyperplasia                                                                 1 (1%)                                
   Liver                                              (70)         (70)         (70)         (68)         (70)                      
      Angiectasis                                      1 (1%)       2 (3%)       2 (3%)       1 (1%)       2 (3%)                   
      Basophilic Focus                                26 (37%)     34 (49%)     31 (44%)     31 (46%)     29 (41%)                  
      Clear Cell Focus                                 2 (3%)       4 (6%)                    4 (6%)       5 (7%)                   
      Degeneration, Cystic                             1 (1%)       1 (1%)                                 1 (1%)                   
      Eosinophilic Focus                              10 (14%)     12 (17%)     13 (19%)     12 (18%)     17 (24%)                  
      Eosinophilic Focus, Multiple                                                                         1 (1%)                   
      Hematopoietic Cell Proliferation                 1 (1%)       3 (4%)                    1 (1%)       2 (3%)                   
      Hemorrhage                                                                              4 (6%)                                
      Hepatodiaphragmatic Nodule                      14 (20%)     12 (17%)     10 (14%)      9 (13%)     19 (27%)                  
      Inflammation, Granulomatous                     12 (17%)      9 (13%)      9 (13%)      9 (13%)     10 (14%)                  
      Mixed Cell Focus                                 2 (3%)       3 (4%)       6 (9%)       8 (12%)      7 (10%)                  

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

                                                             Page    2                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Necrosis, Focal                                  6 (9%)       2 (3%)       3 (4%)       5 (7%)       3 (4%)                   
      Bile Duct, Cyst                                                                         1 (1%)       1 (1%)                   
      Bile Duct, Hyperplasia                          17 (24%)     18 (26%)     20 (29%)     18 (26%)     24 (34%)                  
      Centrilobular, Atrophy                                        1 (1%)                                                          
      Centrilobular, Necrosis                                       1 (1%)                                 1 (1%)                   
      Hepatocyte, Vacuolization Cytoplasmic           14 (20%)      7 (10%)     14 (20%)      9 (13%)      3 (4%)                   
      Kupffer Cell, Pigmentation                      12 (17%)      9 (13%)     14 (20%)      7 (10%)      9 (13%)                  
   Mesentery                                          (11)         (5)          (13)         (10)         (7)                       
      Accessory Spleen                                 1 (9%)       3 (60%)      1 (8%)                    2 (29%)                  
      Fat, Necrosis                                    9 (82%)      2 (40%)     12 (92%)      8 (80%)      5 (71%)                  
   Pancreas                                           (70)         (70)         (70)         (67)         (69)                      
      Atrophy                                         20 (29%)     20 (29%)     22 (31%)     14 (21%)     13 (19%)                  
      Metaplasia, Hepatocyte                           1 (1%)                                                                       
      Acinus, Cytoplasmic Alteration                                1 (1%)       1 (1%)                    1 (1%)                   
      Acinus, Hyperplasia, Focal                                                 1 (1%)       2 (3%)                                
   Salivary Glands                                    (70)         (70)         (70)         (68)         (70)                      
      Atrophy                                          2 (3%)                                 1 (1%)                                
      Cyst                                                          1 (1%)                                                          
      Inflammation, Chronic                                         1 (1%)                                                          
   Stomach, Forestomach                               (70)         (70)         (70)         (67)         (69)                      
      Edema                                            4 (6%)       2 (3%)       3 (4%)       4 (6%)                                
      Erosion                                          1 (1%)       2 (3%)                                 1 (1%)                   
      Hyperplasia                                                                             1 (1%)       1 (1%)                   
      Ulcer                                            2 (3%)       4 (6%)       4 (6%)       3 (4%)       2 (3%)                   
      Mucosa, Hyperplasia                              5 (7%)       9 (13%)      9 (13%)      8 (12%)      5 (7%)                   
   Stomach, Glandular                                 (70)         (70)         (70)         (67)         (70)                      
      Edema                                            1 (1%)       1 (1%)       1 (1%)       2 (3%)                                
      Erosion                                          3 (4%)       1 (1%)       2 (3%)       6 (9%)       2 (3%)                   
      Ulcer                                            2 (3%)       4 (6%)       4 (6%)       1 (1%)                                
   Tongue                                             (1)          (1)          (1)          (4)          (1)                       
      Epithelium, Hyperplasia                                                                 2 (50%)      1 (100%)                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (70)         (70)         (70)         (68)         (70)                      
      Inflammation, Subacute                                        1 (1%)                                                          
   Heart                                              (70)         (70)         (70)         (68)         (70)                      
      Cardiomyopathy                                  28 (40%)     35 (50%)     32 (46%)     26 (38%)     28 (40%)                  
      Thrombosis                                       3 (4%)       1 (1%)       3 (4%)                                             
      Valve, Inflammation, Chronic                     1 (1%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page    3                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (70)         (70)         (70)         (68)         (70)                      
      Accessory Adrenal Cortical Nodule               14 (20%)      9 (13%)     14 (20%)      9 (13%)     10 (14%)                  
      Atrophy                                          1 (1%)                                                                       
      Degeneration, Fatty                              9 (13%)      8 (11%)     16 (23%)     17 (25%)     12 (17%)                  
      Fibrosis                                                      1 (1%)                                                          
      Hemorrhage                                       1 (1%)                                 2 (3%)       1 (1%)                   
      Hyperplasia, Diffuse                             3 (4%)                    1 (1%)       1 (1%)       1 (1%)                   
      Hyperplasia, Focal                               4 (6%)       6 (9%)       7 (10%)      4 (6%)       2 (3%)                   
      Hypertrophy, Focal                               9 (13%)      8 (11%)      6 (9%)       4 (6%)       7 (10%)                  
      Metaplasia, Osseous                                                                     1 (1%)                                
      Necrosis                                                      2 (3%)       2 (3%)       1 (1%)                                
   Adrenal Medulla                                    (70)         (70)         (70)         (68)         (70)                      
      Hyperplasia                                      5 (7%)       7 (10%)     11 (16%)      7 (10%)      7 (10%)                  
   Islets, Pancreatic                                 (70)         (70)         (69)         (67)         (69)                      
      Hyperplasia                                      1 (1%)       1 (1%)                                                          
   Parathyroid Gland                                  (62)         (64)         (65)         (63)         (62)                      
      Hyperplasia                                      1 (2%)                                 1 (2%)       1 (2%)                   
   Pituitary Gland                                    (70)         (69)         (70)         (67)         (70)                      
      Pars Distalis, Angiectasis                       8 (11%)      7 (10%)      3 (4%)       6 (9%)       7 (10%)                  
      Pars Distalis, Atypia Cellular                                1 (1%)                                                          
      Pars Distalis, Cyst                             16 (23%)     11 (16%)     25 (36%)     17 (25%)     19 (27%)                  
      Pars Distalis, Hyperplasia, Focal                9 (13%)      7 (10%)     15 (21%)      1 (1%)       9 (13%)                  
      Pars Intermedia, Angiectasis                                  2 (3%)       2 (3%)                                             
      Pars Intermedia, Cyst                            2 (3%)                    5 (7%)       4 (6%)       3 (4%)                   
   Thyroid Gland                                      (70)         (69)         (70)         (67)         (70)                      
      Ectopic Thymus                                   1 (1%)       1 (1%)                    1 (1%)                                
      Ultimobranchial Cyst                             4 (6%)       2 (3%)                    4 (6%)       2 (3%)                   
      C-Cell, Hyperplasia                              8 (11%)      9 (13%)      9 (13%)      3 (4%)       8 (11%)                  
      Follicle, Cyst                                   1 (1%)                                 2 (3%)       1 (1%)                   
      Follicular Cell, Hyperplasia                                  1 (1%)                                 1 (1%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (68)         (69)         (69)         (68)         (70)                      
      Cyst                                             2 (3%)       5 (7%)       7 (10%)      6 (9%)       5 (7%)                   
      Cyst, Multiple                                   1 (1%)                                                                       
      Fibrosis                                                      1 (1%)                                                          
      Hyperplasia                                      3 (4%)       4 (6%)       6 (9%)       3 (4%)       4 (6%)                   
      Inflammation, Chronic                            3 (4%)       1 (1%)       2 (3%)       2 (3%)       2 (3%)                   
      Inflammation, Suppurative                        2 (3%)                    3 (4%)       3 (4%)       1 (1%)                   

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

                                                             Page    4                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Ovary                                              (70)         (70)         (70)         (67)         (70)                      
      Angiectasis                                                   1 (1%)                                                          
      Cyst                                            17 (24%)      9 (13%)     11 (16%)     19 (28%)     18 (26%)                  
   Uterus                                             (70)         (70)         (70)         (68)         (70)                      
      Hydrometra                                       4 (6%)       9 (13%)     10 (14%)      4 (6%)       9 (13%)                  
      Hyperplasia, Cystic                              4 (6%)       4 (6%)       5 (7%)       2 (3%)       3 (4%)                   
      Cervix, Hypertrophy                                                                     1 (1%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (70)         (70)         (70)         (67)         (70)                      
      Depletion Cellular                               1 (1%)                                 1 (1%)                                
      Fibrosis                                                                                             1 (1%)                   
      Hyperplasia                                      1 (1%)       1 (1%)                                                          
      Infiltration Cellular, Histiocyte                                                       1 (1%)                                
      Inflammation, Granulomatous                                                             1 (1%)                                
      Myelofibrosis                                    2 (3%)       1 (1%)       4 (6%)       1 (1%)       3 (4%)                   
      Stromal Cell, Hyperplasia                                     1 (1%)                                                          
   Lymph Node                                         (20)         (14)         (24)         (19)         (18)                      
      Hyperplasia, Lymphoid                                                      1 (4%)                                             
      Iliac, Hemorrhage                                             1 (7%)                                                          
      Iliac, Hyperplasia, Lymphoid                                  1 (7%)                                                          
      Inguinal, Ectasia                                                                       1 (5%)                                
      Inguinal, Hemorrhage                                                                    1 (5%)                                
      Inguinal, Hyperplasia, Lymphoid                                                         1 (5%)                                
      Mediastinal, Ectasia                             1 (5%)                                                                       
      Mediastinal, Hemorrhage                          3 (15%)      1 (7%)       1 (4%)       7 (37%)                               
      Mediastinal, Hyperplasia, Lymphoid               1 (5%)                                                                       
      Mediastinal, Pigmentation                       14 (70%)      3 (21%)      9 (38%)     11 (58%)      6 (33%)                  
      Pancreatic, Hemorrhage                                                                  1 (5%)                                
      Pancreatic, Pigmentation                         1 (5%)       2 (14%)      6 (25%)      4 (21%)      4 (22%)                  
      Renal, Hemorrhage                                                                                    2 (11%)                  
      Renal, Pigmentation                              1 (5%)       3 (21%)      2 (8%)                    7 (39%)                  
   Lymph Node, Mandibular                             (69)         (70)         (70)         (65)         (70)                      
      Ectasia                                          2 (3%)       2 (3%)       2 (3%)       4 (6%)       1 (1%)                   
      Hemorrhage                                       5 (7%)       3 (4%)       3 (4%)       5 (8%)       2 (3%)                   
      Hyperplasia, Lymphoid                           13 (19%)     12 (17%)      9 (13%)     14 (22%)      7 (10%)                  
      Hyperplasia, Plasma Cell                         1 (1%)                                              1 (1%)                   
      Pigmentation                                    20 (29%)     27 (39%)     19 (27%)     26 (40%)     25 (36%)                  
   Lymph Node, Mesenteric                             (68)         (69)         (70)         (65)         (70)                      
      Ectasia                                          2 (3%)                    2 (3%)       2 (3%)       2 (3%)                   
      Hemorrhage                                                    4 (6%)       1 (1%)       9 (14%)      7 (10%)                  
      Hyperplasia, Lymphoid                            2 (3%)       4 (6%)       2 (3%)       3 (5%)       4 (6%)                   
      Pigmentation                                                  1 (1%)                    1 (2%)       1 (1%)                   
   Spleen                                             (70)         (70)         (70)         (67)         (70)                      
      Developmental Malformation                                    1 (1%)                                                          

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

                                                             Page    5                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Fibrosis                                         3 (4%)       4 (6%)       5 (7%)       3 (4%)       3 (4%)                   
      Hematopoietic Cell Proliferation                15 (21%)     12 (17%)     12 (17%)     17 (25%)     11 (16%)                  
      Hemorrhage                                                                                           1 (1%)                   
      Hyperplasia, Lymphoid                                                                                1 (1%)                   
      Metaplasia, Lipocyte                                                                                 1 (1%)                   
      Necrosis                                                                   2 (3%)       2 (3%)       1 (1%)                   
      Pigmentation, Hemosiderin                       29 (41%)     31 (44%)     34 (49%)     41 (61%)     51 (73%)                  
      Lymphoid Follicle, Atrophy                       1 (1%)                    1 (1%)                                             
      Red Pulp, Atrophy                                1 (1%)       1 (1%)                                 1 (1%)                   
   Thymus                                             (66)         (66)         (70)         (67)         (67)                      
      Hemorrhage                                                    1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (70)         (70)         (69)         (68)         (70)                      
      Dilatation                                      37 (53%)     33 (47%)     48 (70%)     39 (57%)     34 (49%)                  
      Galactocele                                      5 (7%)       1 (1%)       4 (6%)       1 (1%)       5 (7%)                   
      Hyperplasia                                     12 (17%)     12 (17%)      6 (9%)      11 (16%)     15 (21%)                  
      Inflammation, Suppurative                                                                            1 (1%)                   
   Skin                                               (70)         (69)         (70)         (67)         (70)                      
      Cyst Epithelial Inclusion                        1 (1%)                                              1 (1%)                   
      Hyperkeratosis                                   1 (1%)       1 (1%)                                                          
      Inflammation, Chronic                            1 (1%)       2 (3%)                                                          
      Ulcer                                                         2 (3%)       1 (1%)       1 (1%)       2 (3%)                   
      Epidermis, Hyperplasia                           1 (1%)       2 (3%)                    2 (3%)       2 (3%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (70)         (70)         (69)         (68)         (70)                      
      Fibrous Osteodystrophy                                                                  1 (1%)       1 (1%)                   
      Hyperostosis                                                                                         1 (1%)                   
      Cranium, Osteopetrosis                           8 (11%)     17 (24%)      9 (13%)      6 (9%)       9 (13%)                  
      Femur, Osteopetrosis                             9 (13%)     17 (24%)     10 (14%)      6 (9%)       5 (7%)                   
   Skeletal Muscle                                    (1)          (1)          (1)          (1)          (1)                       
      Hemorrhage                                                                 1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (70)         (70)         (70)         (68)         (70)                      
      Atrophy                                         19 (27%)     22 (31%)     20 (29%)     25 (37%)     22 (31%)                  
      Gliosis                                                       1 (1%)                                                          
      Hemorrhage                                                                                           1 (1%)                   
      Hydrocephalus                                    4 (6%)       4 (6%)       1 (1%)       3 (4%)       8 (11%)                  
      Necrosis                                                      1 (1%)       1 (1%)       1 (1%)                                

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

                                                             Page    6                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (70)         (70)         (70)         (68)         (70)                      
      Congestion                                       1 (1%)                                                                       
      Edema                                                         2 (3%)       1 (1%)                                             
      Hemorrhage                                       2 (3%)       1 (1%)       1 (1%)       1 (1%)       2 (3%)                   
      Infiltration Cellular, Histiocyte               28 (40%)     33 (47%)     24 (34%)     30 (44%)     23 (33%)                  
      Inflammation, Subacute                           7 (10%)      4 (6%)       1 (1%)       3 (4%)       2 (3%)                   
      Thrombosis                                       1 (1%)                                                                       
      Alveolar Epithelium, Hyperplasia                 5 (7%)       6 (9%)       5 (7%)       2 (3%)       5 (7%)                   
   Nose                                               (70)         (70)         (70)         (68)         (70)                      
      Foreign Body                                     3 (4%)       1 (1%)                    3 (4%)                                
      Inflammation, Suppurative                        5 (7%)       3 (4%)       2 (3%)      11 (16%)      3 (4%)                   
      Goblet Cell, Hyperplasia                        10 (14%)      8 (11%)      2 (3%)       3 (4%)       7 (10%)                  
      Mucosa, Hyperplasia                              5 (7%)       1 (1%)       1 (1%)      12 (18%)      1 (1%)                   
      Mucosa, Metaplasia, Squamous                     3 (4%)       2 (3%)                    4 (6%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (4)                       (1)          (3)          (1)                       
      Cataract                                         3 (75%)                   1 (100%)     3 (100%)     1 (100%)                 
      Hemorrhage                                       1 (25%)                                1 (33%)                               
      Inflammation, Chronic                                                                   1 (33%)                               
      Retina, Degeneration                             4 (100%)                  1 (100%)     3 (100%)     1 (100%)                 
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (70)         (70)         (70)         (67)         (70)                      
      Cyst                                                                       1 (1%)                    3 (4%)                   
      Hydronephrosis                                                1 (1%)       1 (1%)                                             
      Inflammation, Chronic                            1 (1%)       1 (1%)       1 (1%)       3 (4%)       5 (7%)                   
      Inflammation, Suppurative                        2 (3%)       1 (1%)       1 (1%)                                             
      Mineralization                                  67 (96%)     62 (89%)     66 (94%)     54 (81%)     58 (83%)                  
      Nephropathy                                     37 (53%)     38 (54%)     38 (54%)     37 (55%)     39 (56%)                  
      Renal Tubule, Atrophy                            1 (1%)       1 (1%)       4 (6%)                    5 (7%)                   
      Renal Tubule, Cytoplasmic Alteration             5 (7%)       3 (4%)       3 (4%)       4 (6%)       2 (3%)                   
      Renal Tubule, Dilatation                                                                1 (1%)       1 (1%)                   
      Renal Tubule, Necrosis                           2 (3%)       1 (1%)       1 (1%)       1 (1%)       2 (3%)                   
      Renal Tubule, Pigmentation                      15 (21%)      9 (13%)     16 (23%)     11 (16%)     16 (23%)                  
      Transitional Epithelium, Hyperplasia             2 (3%)       4 (6%)       2 (3%)       6 (9%)       3 (4%)                   
   Urinary Bladder                                    (69)         (70)         (70)         (68)         (69)                      

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

                                                             Page    7                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS FEMALE                   UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Transitional Epithelium, Hyperplasia                          1 (1%)       1 (1%)       1 (1%)       2 (3%)                   
                                                                                                                                    

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

                                                             Page    8                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________

DISPOSITION SUMMARY                                                                                                                 

  Animals Initially In Study                          70           70           70           70           70                        

  Scheduled Sacrifice                                 10           10           10           10           10                        
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                48           41           51           50           42                        
    Natural Death                                      4            7            2            7            4                        
  Survivors                                                                                                                         
    Terminal Sacrifice                                 8           12            7            1           14                        
  Other                                                                                       2                                     

  Animals Examined Microscopically                    70           70           70           68           70                        
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (68)         (70)         (68)         (68)         (70)                      
      Edema                                                                                   1 (1%)       1 (1%)                   
      Parasite Metazoan                                7 (10%)      6 (9%)       6 (9%)       3 (4%)       3 (4%)                   
   Intestine Large, Rectum                            (69)         (68)         (70)         (68)         (69)                      
      Edema                                            2 (3%)                                 1 (1%)       1 (1%)                   
      Hemorrhage                                                                                           1 (1%)                   
      Parasite Metazoan                                6 (9%)       5 (7%)                    1 (1%)       8 (12%)                  
   Intestine Large, Cecum                             (70)         (70)         (68)         (68)         (70)                      
      Edema                                            3 (4%)       2 (3%)       2 (3%)       3 (4%)       3 (4%)                   
      Parasite Metazoan                                1 (1%)       2 (3%)       2 (3%)                    3 (4%)                   
   Intestine Small, Duodenum                          (69)         (70)         (70)         (68)         (70)                      
      Epithelium, Hyperplasia                          2 (3%)                                              4 (6%)                   
   Intestine Small, Jejunum                           (70)         (69)         (70)         (67)         (70)                      
      Metaplasia, Osseous                                                                     1 (1%)                                
      Epithelium, Hyperplasia                          1 (1%)                                              1 (1%)                   
   Intestine Small, Ileum                             (70)         (69)         (69)         (68)         (69)                      
      Diverticulum                                                  1 (1%)                                                          
      Hyperplasia, Lymphoid                                                      1 (1%)                                             
      Ulcer                                                                                   1 (1%)                                
   Liver                                              (70)         (70)         (70)         (68)         (70)                      
      Angiectasis                                     10 (14%)      5 (7%)       1 (1%)       4 (6%)       7 (10%)                  
      Basophilic Focus                                 7 (10%)      7 (10%)      3 (4%)       2 (3%)       7 (10%)                  
      Clear Cell Focus                                 1 (1%)       1 (1%)       3 (4%)       1 (1%)       5 (7%)                   
      Congestion                                                    1 (1%)                                                          
      Degeneration, Cystic                            23 (33%)      9 (13%)     16 (23%)     11 (16%)      5 (7%)                   
      Eosinophilic Focus                              10 (14%)      6 (9%)       4 (6%)       1 (1%)       4 (6%)                   
      Eosinophilic Focus, Multiple                     1 (1%)                                                                       
      Fibrosis                                         1 (1%)                    1 (1%)       1 (1%)                                
      Hematopoietic Cell Proliferation                 1 (1%)                                 1 (1%)                                
      Hemorrhage                                                    1 (1%)                    1 (1%)                                
      Hepatodiaphragmatic Nodule                       7 (10%)      4 (6%)       8 (11%)      4 (6%)       8 (11%)                  

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

                                                             Page    9                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Inflammation, Subacute                           1 (1%)       2 (3%)       1 (1%)       1 (1%)       2 (3%)                   
      Mixed Cell Focus                                 2 (3%)                                              2 (3%)                   
      Necrosis, Focal                                  8 (11%)      7 (10%)      6 (9%)       3 (4%)       2 (3%)                   
      Thrombosis                                       1 (1%)       1 (1%)       3 (4%)                    1 (1%)                   
      Bile Duct, Cyst                                  2 (3%)                                                                       
      Bile Duct, Hyperplasia                          52 (74%)     47 (67%)     49 (70%)     43 (63%)     26 (37%)                  
      Centrilobular, Atrophy                                                     1 (1%)                                             
      Centrilobular, Fibrosis                                                                              1 (1%)                   
      Centrilobular, Necrosis                          2 (3%)       3 (4%)       1 (1%)                    2 (3%)                   
      Hepatocyte, Vacuolization Cytoplasmic            6 (9%)      10 (14%)      4 (6%)       7 (10%)      3 (4%)                   
      Kupffer Cell, Hyperplasia                                                  1 (1%)                                             
      Kupffer Cell, Pigmentation                      11 (16%)     15 (21%)     18 (26%)      8 (12%)     10 (14%)                  
   Mesentery                                          (20)         (15)         (11)         (7)          (16)                      
      Accessory Spleen                                 1 (5%)       2 (13%)      3 (27%)                   4 (25%)                  
      Fat, Necrosis                                   16 (80%)     12 (80%)      7 (64%)      6 (86%)     13 (81%)                  
   Pancreas                                           (70)         (70)         (69)         (68)         (70)                      
      Atrophy                                         16 (23%)     19 (27%)     19 (28%)     12 (18%)     17 (24%)                  
      Acinus, Cytoplasmic Alteration                   3 (4%)       1 (1%)       1 (1%)       1 (1%)       4 (6%)                   
      Acinus, Hyperplasia, Focal                       2 (3%)       1 (1%)       3 (4%)       2 (3%)       2 (3%)                   
   Salivary Glands                                    (70)         (70)         (70)         (68)         (70)                      
      Atrophy                                                       1 (1%)       1 (1%)                                             
   Stomach, Forestomach                               (70)         (70)         (70)         (68)         (69)                      
      Edema                                            9 (13%)      2 (3%)       4 (6%)       5 (7%)       6 (9%)                   
      Erosion                                                       2 (3%)       2 (3%)                                             
      Hyperplasia                                      8 (11%)      7 (10%)      7 (10%)      9 (13%)     12 (17%)                  
      Inflammation, Subacute                                        2 (3%)                                                          
      Ulcer                                            8 (11%)     10 (14%)      1 (1%)       3 (4%)       7 (10%)                  
      Mucosa, Hyperplasia                              1 (1%)                    1 (1%)                                             
   Stomach, Glandular                                 (70)         (70)         (69)         (68)         (70)                      
      Edema                                            1 (1%)       2 (3%)       1 (1%)       3 (4%)       3 (4%)                   
      Erosion                                          1 (1%)      11 (16%)      3 (4%)       2 (3%)       1 (1%)                   
      Mineralization                                   1 (1%)                    2 (3%)       5 (7%)                                
      Ulcer                                            3 (4%)       5 (7%)       3 (4%)       3 (4%)                                
   Tongue                                             (1)          (2)          (2)          (1)          (4)                       
      Epithelium, Hyperplasia                                       1 (50%)      2 (100%)     1 (100%)     2 (50%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (70)         (70)         (70)         (68)         (70)                      
      Hypertrophy                                      1 (1%)                    3 (4%)       1 (1%)       4 (6%)                   
      Inflammation, Subacute                           1 (1%)                    1 (1%)       1 (1%)                                
      Mineralization                                                             1 (1%)       1 (1%)                                
      Thrombosis                                                                              1 (1%)                                
   Heart                                              (70)         (70)         (70)         (68)         (70)                      
      Cardiomyopathy                                  42 (60%)     42 (60%)     43 (61%)     37 (54%)     39 (56%)                  
      Mineralization                                                             1 (1%)                                             

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

                                                             Page   10                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
CARDIOVASCULAR SYSTEM - CONT                                                                                                        
      Necrosis                                         1 (1%)                                                                       
      Thrombosis                                       6 (9%)       9 (13%)      8 (11%)      4 (6%)                                
      Endocardium, Hyperplasia                         1 (1%)                                                                       
      Schwann Cell, Hyperplasia                                     1 (1%)       1 (1%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (70)         (70)         (70)         (68)         (70)                      
      Accessory Adrenal Cortical Nodule               18 (26%)     17 (24%)     10 (14%)     12 (18%)     14 (20%)                  
      Degeneration, Cystic                                                       1 (1%)                                             
      Degeneration, Fatty                              9 (13%)      7 (10%)     10 (14%)      8 (12%)      7 (10%)                  
      Hemorrhage                                       1 (1%)       3 (4%)                                 2 (3%)                   
      Hyperplasia, Focal                               4 (6%)       2 (3%)       2 (3%)       2 (3%)       3 (4%)                   
      Hypertrophy, Focal                               6 (9%)       5 (7%)       5 (7%)       2 (3%)       2 (3%)                   
      Necrosis                                         1 (1%)       1 (1%)                                                          
   Adrenal Medulla                                    (70)         (70)         (69)         (68)         (70)                      
      Hyperplasia                                     26 (37%)     30 (43%)     22 (32%)     15 (22%)     12 (17%)                  
   Islets, Pancreatic                                 (70)         (70)         (69)         (68)         (70)                      
      Hyperplasia                                      3 (4%)       3 (4%)       1 (1%)       2 (3%)       1 (1%)                   
   Parathyroid Gland                                  (65)         (66)         (64)         (65)         (66)                      
      Hyperplasia                                      6 (9%)       1 (2%)       8 (13%)      7 (11%)      9 (14%)                  
   Pituitary Gland                                    (70)         (69)         (68)         (66)         (70)                      
      Nuclear Alteration                                                                                   1 (1%)                   
      Pars Distalis, Angiectasis                       4 (6%)       2 (3%)       2 (3%)       1 (2%)                                
      Pars Distalis, Cyst                              6 (9%)       9 (13%)      3 (4%)       4 (6%)       7 (10%)                  
      Pars Distalis, Cyst, Hemorrhagic                 1 (1%)                                 1 (2%)                                
      Pars Distalis, Hyperplasia, Focal               10 (14%)     10 (14%)      8 (12%)      8 (12%)     14 (20%)                  
      Pars Intermedia, Angiectasis                                               1 (1%)       2 (3%)       1 (1%)                   
      Pars Intermedia, Cyst                            1 (1%)       8 (12%)      6 (9%)       5 (8%)       2 (3%)                   
   Thyroid Gland                                      (70)         (70)         (70)         (68)         (70)                      
      Ectopic Thymus                                   1 (1%)       1 (1%)                                                          
      Ultimobranchial Cyst                             2 (3%)       3 (4%)       2 (3%)       1 (1%)       8 (11%)                  
      C-Cell, Hyperplasia                              9 (13%)      6 (9%)       8 (11%)      9 (13%)      7 (10%)                  
      Follicle, Cyst                                   1 (1%)       1 (1%)       3 (4%)       1 (1%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    

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

                                                             Page   11                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (70)         (70)         (70)         (67)         (70)                      
      Atypia Cellular                                 27 (39%)     29 (41%)     26 (37%)     28 (42%)     25 (36%)                  
      Granuloma Sperm                                                                                      1 (1%)                   
   Preputial Gland                                    (70)         (70)         (70)         (68)         (70)                      
      Cyst                                             3 (4%)                    3 (4%)       4 (6%)       4 (6%)                   
      Hyperplasia                                      3 (4%)       1 (1%)       2 (3%)       4 (6%)       2 (3%)                   
      Inflammation, Chronic                           26 (37%)     12 (17%)     16 (23%)     18 (26%)     12 (17%)                  
      Inflammation, Suppurative                        3 (4%)       1 (1%)       7 (10%)      3 (4%)       5 (7%)                   
   Prostate                                           (70)         (70)         (70)         (68)         (70)                      
      Cyst                                             1 (1%)                                                                       
      Fibrosis                                         3 (4%)                    1 (1%)                                             
      Inflammation, Chronic                            5 (7%)       2 (3%)       1 (1%)                                             
      Inflammation, Suppurative                       36 (51%)     29 (41%)     41 (59%)     41 (60%)     23 (33%)                  
      Epithelium, Hyperplasia                         11 (16%)     12 (17%)     10 (14%)      6 (9%)       8 (11%)                  
   Testes                                             (70)         (70)         (70)         (67)         (70)                      
      Interstitial Cell, Hyperplasia                   4 (6%)       3 (4%)       7 (10%)      6 (9%)       3 (4%)                   
      Seminiferous Tubule, Atrophy                     7 (10%)      1 (1%)       6 (9%)       2 (3%)       5 (7%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (70)         (70)         (70)         (68)         (70)                      
      Depletion Cellular                                            1 (1%)                                                          
      Hyperplasia                                      6 (9%)                    5 (7%)       2 (3%)       7 (10%)                  
      Infiltration Cellular, Histiocyte                                                                    2 (3%)                   
      Myelofibrosis                                    4 (6%)       2 (3%)       8 (11%)                   2 (3%)                   
   Lymph Node                                         (33)         (37)         (37)         (36)         (35)                      
      Deep Cervical, Hyperplasia, Lymphoid                                       1 (3%)                                             
      Iliac, Hemorrhage                                1 (3%)                                                                       
      Inguinal, Hyperplasia, Lymphoid                  2 (6%)                                              1 (3%)                   
      Mediastinal, Congestion                                                                              2 (6%)                   
      Mediastinal, Hemorrhage                          3 (9%)       5 (14%)      3 (8%)       3 (8%)       3 (9%)                   
      Mediastinal, Hyperplasia, Lymphoid               1 (3%)       3 (8%)       2 (5%)       1 (3%)       2 (6%)                   
      Mediastinal, Pigmentation                       13 (39%)     14 (38%)     14 (38%)     17 (47%)     16 (46%)                  
      Pancreatic, Ectasia                                                        1 (3%)                                             
      Pancreatic, Hemorrhage                                        2 (5%)                                                          
      Pancreatic, Hyperplasia, Plasma Cell                                                                 1 (3%)                   
      Pancreatic, Pigmentation                         9 (27%)      4 (11%)      3 (8%)       4 (11%)      3 (9%)                   
      Renal, Ectasia                                                                                       2 (6%)                   
      Renal, Hemorrhage                                1 (3%)       1 (3%)       1 (3%)       3 (8%)       2 (6%)                   
      Renal, Hyperplasia, Lymphoid                                                            1 (3%)                                
      Renal, Pigmentation                              8 (24%)      5 (14%)      8 (22%)      8 (22%)      7 (20%)                  
   Lymph Node, Mandibular                             (70)         (69)         (70)         (68)         (70)                      
      Ectasia                                          3 (4%)       8 (12%)      8 (11%)      7 (10%)      6 (9%)                   
      Hemorrhage                                       2 (3%)       1 (1%)                    2 (3%)       3 (4%)                   
      Hyperplasia, Lymphoid                           11 (16%)     11 (16%)      7 (10%)     10 (15%)     17 (24%)                  

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

                                                             Page   12                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Hyperplasia, Plasma Cell                                                   1 (1%)       1 (1%)                                
      Pigmentation                                     6 (9%)       8 (12%)      3 (4%)       7 (10%)      5 (7%)                   
   Lymph Node, Mesenteric                             (70)         (68)         (68)         (67)         (70)                      
      Ectasia                                          7 (10%)      1 (1%)       1 (1%)       7 (10%)     10 (14%)                  
      Hemorrhage                                       1 (1%)       3 (4%)       3 (4%)       1 (1%)       2 (3%)                   
      Hyperplasia, Lymphoid                            3 (4%)       2 (3%)       1 (1%)      10 (15%)      6 (9%)                   
      Pigmentation                                                               1 (1%)                                             
   Spleen                                             (70)         (70)         (70)         (68)         (70)                      
      Angiectasis                                                   1 (1%)                                                          
      Congestion                                       1 (1%)                                                                       
      Fibrosis                                        21 (30%)     19 (27%)     20 (29%)      9 (13%)     13 (19%)                  
      Hematopoietic Cell Proliferation                 7 (10%)      6 (9%)       6 (9%)       3 (4%)       8 (11%)                  
      Metaplasia, Lipocyte                             1 (1%)                                                                       
      Necrosis                                         2 (3%)       3 (4%)       2 (3%)       3 (4%)                                
      Pigmentation, Hemosiderin                       13 (19%)     11 (16%)      9 (13%)     14 (21%)     17 (24%)                  
      Lymphoid Follicle, Atrophy                       1 (1%)                                                                       
      Red Pulp, Atrophy                                                          1 (1%)                                             
   Thymus                                             (68)         (65)         (65)         (64)         (66)                      
      Cyst                                                          1 (2%)                                                          
      Ectopic Parathyroid Gland                                                  1 (2%)       2 (3%)                                
      Hemorrhage                                                    1 (2%)                    3 (5%)       1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (67)         (68)         (67)         (66)         (68)                      
      Dilatation                                      23 (34%)     27 (40%)     24 (36%)     17 (26%)     10 (15%)                  
      Galactocele                                      5 (7%)                    4 (6%)       1 (2%)       2 (3%)                   
      Hyperplasia                                      7 (10%)     12 (18%)      4 (6%)       5 (8%)       6 (9%)                   
   Skin                                               (70)         (70)         (70)         (67)         (70)                      
      Cyst Epithelial Inclusion                        2 (3%)                    1 (1%)       1 (1%)       1 (1%)                   
      Hemorrhage                                                                                           1 (1%)                   
      Hyperkeratosis                                                1 (1%)       1 (1%)       2 (3%)       1 (1%)                   
      Inflammation, Chronic                                         1 (1%)       1 (1%)       2 (3%)                                
      Ulcer                                                                      1 (1%)       1 (1%)                                
      Epidermis, Hyperplasia                           1 (1%)       1 (1%)       1 (1%)       1 (1%)       1 (1%)                   
      Subcutaneous Tissue, Inflammation,                                                                                            
          Suppurative                                               1 (1%)                                                          
      Subcutaneous Tissue, Thrombosis                                                                      1 (1%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (70)         (70)         (70)         (68)         (70)                      
      Fibrous Osteodystrophy                           6 (9%)       1 (1%)       5 (7%)       5 (7%)       7 (10%)                  
      Hyperostosis                                     1 (1%)                                 1 (1%)                                
      Femur, Osteopetrosis                             1 (1%)       2 (3%)       2 (3%)       1 (1%)                                

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

                                                             Page   13                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (70)         (70)         (70)         (68)         (70)                      
      Angiectasis                                                   1 (1%)                                                          
      Atrophy                                         12 (17%)      6 (9%)       8 (11%)      8 (12%)      3 (4%)                   
      Gliosis                                                                                 1 (1%)                                
      Hemorrhage                                       2 (3%)                    1 (1%)       1 (1%)       1 (1%)                   
      Hydrocephalus                                    4 (6%)       3 (4%)       3 (4%)       4 (6%)                                
      Necrosis                                         1 (1%)       2 (3%)                                 1 (1%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (70)         (70)         (70)         (68)         (70)                      
      Congestion                                       2 (3%)                                                                       
      Edema                                            1 (1%)       1 (1%)                                 1 (1%)                   
      Hemorrhage                                       3 (4%)       2 (3%)       5 (7%)       2 (3%)       2 (3%)                   
      Infiltration Cellular, Histiocyte               19 (27%)     17 (24%)     21 (30%)     10 (15%)     14 (20%)                  
      Inflammation, Subacute                           4 (6%)       7 (10%)      7 (10%)      7 (10%)      8 (11%)                  
      Metaplasia, Osseous                              1 (1%)                                                                       
      Mineralization                                                             1 (1%)       1 (1%)                                
      Alveolar Epithelium, Hyperplasia                 7 (10%)      8 (11%)     10 (14%)      6 (9%)      10 (14%)                  
   Nose                                               (70)         (70)         (70)         (68)         (70)                      
      Foreign Body                                     6 (9%)       5 (7%)       8 (11%)      2 (3%)       2 (3%)                   
      Inflammation, Suppurative                       17 (24%)     10 (14%)     22 (31%)     15 (22%)     11 (16%)                  
      Goblet Cell, Hyperplasia                         5 (7%)       4 (6%)       3 (4%)       9 (13%)     20 (29%)                  
      Mucosa, Hyperplasia                             14 (20%)      8 (11%)     18 (26%)     13 (19%)     10 (14%)                  
      Mucosa, Metaplasia, Squamous                     8 (11%)      4 (6%)      13 (19%)      8 (12%)      7 (10%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (4)          (4)          (2)          (1)          (2)                       
      Atrophy                                          2 (50%)                                             1 (50%)                  
      Cataract                                         1 (25%)      2 (50%)                                1 (50%)                  
      Inflammation, Chronic                                         1 (25%)      1 (50%)                                            
      Retina, Degeneration                             1 (25%)      2 (50%)                                1 (50%)                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (70)         (70)         (70)         (68)         (70)                      
      Cyst                                             2 (3%)       1 (1%)       3 (4%)       7 (10%)     11 (16%)                  
      Developmental Malformation                                                 1 (1%)                                             
      Inflammation, Suppurative                        9 (13%)                   8 (11%)      9 (13%)     20 (29%)                  
      Mineralization                                  13 (19%)     13 (19%)      4 (6%)       2 (3%)       1 (1%)                   
      Nephropathy                                     65 (93%)     64 (91%)     65 (93%)     62 (91%)     66 (94%)                  

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

                                                             Page   14                                                              
NTP Experiment-Test: 05217-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                        T-BUTYLHYDROQUINONE                                    Date: 04/04/96  
Route: DOSED FEED                                                                                                 Time: 06:47:04  
____________________________________________________________________________________________________________________________________

         FISCHER 344 RATS MALE                     UNTREATD     0.0%         0.125%       0.25%        0.5%                         
                                                    CONTROL                                                                         
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - CONT                                                                                                               
      Renal Tubule, Accumulation, Hyaline Droplet      1 (1%)       3 (4%)       1 (1%)       2 (3%)       1 (1%)                   
      Renal Tubule, Atrophy                                         1 (1%)                                 1 (1%)                   
      Renal Tubule, Hyperplasia, Focal                                                        1 (1%)                                
      Renal Tubule, Necrosis                           3 (4%)       1 (1%)       1 (1%)       1 (1%)                                
      Renal Tubule, Pigmentation                      18 (26%)     23 (33%)     26 (37%)     17 (25%)     15 (21%)                  
      Transitional Epithelium, Hyperplasia            13 (19%)      2 (3%)      12 (17%)     11 (16%)     21 (30%)                  
   Urinary Bladder                                    (70)         (70)         (70)         (68)         (70)                      
      Hemorrhage                                       1 (1%)       1 (1%)                                                          
      Inflammation, Suppurative                        1 (1%)       1 (1%)                                                          
      Transitional Epithelium, Hyperplasia             2 (3%)                                                                       
                                                                                                                                    

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

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