National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/4148

TDMS Study 93023-06 Pathology Tables

NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01
Route: GAVAGE                                                                                                     Time: 15:11:34

                                                          FINAL#1/RATS




       Facility:  Southern Research Institute

       Chemical CAS #:  142-83-6

       Lock Date:  02/28/00

       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: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                12            9            6            9                                     
    Natural Death                                      1            1            2            4                                     
    Dosing Accident                                                 1            1            6                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                37           38           41           31                                     
    Natural Death                                                   1                                                               
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (48)         (47)         (50)         (48)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
      Perforation                                                                             1 (2%)                                
   Intestine Large, Cecum                             (50)         (50)         (50)         (50)                                   
      Edema                                                         1 (2%)                    2 (4%)                                
      Inflammation, Chronic Active                                  1 (2%)                                                          
   Liver                                              (50)         (50)         (50)         (50)                                   
      Angiectasis                                      1 (2%)       1 (2%)       2 (4%)       2 (4%)                                
      Basophilic Focus                                47 (94%)     49 (98%)     48 (96%)     45 (90%)                               
      Clear Cell Focus                                 7 (14%)      8 (16%)     11 (22%)      4 (8%)                                
      Eosinophilic Focus                               9 (18%)     10 (20%)      6 (12%)      4 (8%)                                
      Hepatodiaphragmatic Nodule                       9 (18%)      6 (12%)      6 (12%)      4 (8%)                                
      Infiltration Cellular, Mixed Cell               15 (30%)     10 (20%)     10 (20%)     17 (34%)                               
      Mixed Cell Focus                                 6 (12%)     12 (24%)      6 (12%)      9 (18%)                               
      Bile Duct, Hyperplasia                           5 (10%)                                1 (2%)                                
      Hepatocyte, Cytomegaly                           2 (4%)                                 1 (2%)                                
      Hepatocyte, Necrosis                             2 (4%)                    1 (2%)       3 (6%)                                
      Hepatocyte, Vacuolization Cytoplasmic            1 (2%)       3 (6%)                    1 (2%)                                
      Kupffer Cell, Pigmentation                       2 (4%)       3 (6%)                    1 (2%)                                
   Mesentery                                          (13)         (16)         (19)         (15)                                   
      Fat, Necrosis                                   13 (100%)    16 (100%)    18 (95%)     15 (100%)                              
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Atrophy                                          7 (14%)     12 (24%)      8 (16%)      8 (16%)                               
      Cyst                                             2 (4%)       4 (8%)       1 (2%)       3 (6%)                                
      Acinus, Cytoplasmic Alteration                   1 (2%)       2 (4%)                    2 (4%)                                
      Acinus, Hyperplasia, Focal                       3 (6%)       2 (4%)       2 (4%)       1 (2%)                                
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                                       2 (4%)       5 (10%)      4 (8%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Necrosis                                                      1 (2%)                                                          
   Stomach, Forestomach                               (50)         (49)         (50)         (50)                                   
      Edema                                            1 (2%)       1 (2%)                    2 (4%)                                
      Erosion                                          1 (2%)                                                                       
      Inflammation, Chronic Active                                               1 (2%)       2 (4%)                                
      Ulcer                                            1 (2%)                                 1 (2%)                                
      Epithelium, Cyst                                                                        1 (2%)                                
      Epithelium, Hyperplasia                          2 (4%)      16 (33%)     37 (74%)     41 (82%)                               
   Stomach, Glandular                                 (50)         (49)         (50)         (50)                                   
      Edema                                            1 (2%)                                                                       
      Erosion                                                                                 1 (2%)                                
      Ulcer                                                                      1 (2%)       1 (2%)                                
   Tongue                                             (1)                       (2)          (1)                                    
      Hyperplasia                                      1 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  20 (40%)     20 (40%)     17 (34%)     13 (26%)                               
      Myocardium, Necrosis                                          1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule               13 (26%)     13 (26%)     13 (26%)     13 (26%)                               
      Angiectasis                                      3 (6%)       2 (4%)       1 (2%)       2 (4%)                                
      Degeneration, Fatty                             12 (24%)     11 (22%)     11 (22%)     11 (22%)                               
      Hyperplasia, Diffuse                             2 (4%)                    1 (2%)       1 (2%)                                
      Hyperplasia, Focal                               3 (6%)       6 (12%)      5 (10%)      4 (8%)                                
      Hypertrophy, Focal                               9 (18%)      9 (18%)      8 (16%)      5 (10%)                               
      Necrosis                                                                                2 (4%)                                
   Adrenal Medulla                                    (50)         (49)         (50)         (50)                                   
      Hyperplasia                                      3 (6%)       1 (2%)       1 (2%)       1 (2%)                                
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      1 (2%)       2 (4%)       1 (2%)                                             
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Pars Distalis, Angiectasis                       9 (18%)      3 (6%)       5 (10%)      2 (4%)                                
      Pars Distalis, Cyst                             22 (44%)     14 (28%)     12 (24%)     15 (30%)                               
      Pars Distalis, Hyperplasia                                    3 (6%)       1 (2%)                                             
      Pars Distalis, Hyperplasia, Focal               13 (26%)      8 (16%)      7 (14%)      9 (18%)                               
      Pars Intermedia, Angiectasis                                               1 (2%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Intermedia, Cyst                                         1 (2%)                                                          
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      Ultimobranchial Cyst                                          2 (4%)                    2 (4%)                                
      C-Cell, Hyperplasia                             24 (48%)     22 (44%)     26 (52%)     14 (28%)                               
      Follicle, Cyst                                                1 (2%)       1 (2%)                                             
      Follicular Cell, Hyperplasia                                                            1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (50)         (50)         (50)                                   
      Cyst                                             8 (16%)      6 (12%)      2 (4%)       2 (4%)                                
      Hyperplasia                                      1 (2%)                                 1 (2%)                                
      Inflammation, Chronic                            1 (2%)       6 (12%)      3 (6%)       5 (10%)                               
   Ovary                                              (50)         (50)         (50)         (50)                                   
      Cyst                                            12 (24%)      7 (14%)      8 (16%)      9 (18%)                               
   Uterus                                             (50)         (50)         (50)         (50)                                   
      Hydrometra                                       2 (4%)       7 (14%)      6 (12%)      2 (4%)                                
      Hyperplasia, Cystic                              3 (6%)       4 (8%)       4 (8%)       5 (10%)                               
      Inflammation, Chronic                                                      1 (2%)       2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      2 (4%)       5 (10%)      5 (10%)      2 (4%)                                
      Infiltration Cellular, Histiocyte                             1 (2%)                                                          
   Lymph Node                                         (29)         (30)         (30)         (38)                                   
      Deep Cervical, Hemorrhage                        1 (3%)       1 (3%)       1 (3%)       1 (3%)                                
      Deep Cervical, Hyperplasia, Lymphoid                                                    1 (3%)                                
      Deep Cervical, Pigmentation                      1 (3%)       1 (3%)       1 (3%)       1 (3%)                                
      Mediastinal, Hemorrhage                                       3 (10%)      4 (13%)      2 (5%)                                
      Mediastinal, Hyperplasia, Lymphoid               5 (17%)      8 (27%)     10 (33%)      3 (8%)                                
      Mediastinal, Pigmentation                        4 (14%)      8 (27%)      7 (23%)      3 (8%)                                
      Pancreatic, Hemorrhage                           8 (28%)      8 (27%)     13 (43%)     17 (45%)                               
      Pancreatic, Hyperplasia                          1 (3%)                                                                       
      Pancreatic, Hyperplasia, Lymphoid               17 (59%)     24 (80%)     18 (60%)     28 (74%)                               
      Pancreatic, Pigmentation                        24 (83%)     25 (83%)     24 (80%)     32 (84%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
   Lymph Node, Mandibular                             (6)          (2)          (5)          (1)                                    
      Ectasia                                          2 (33%)      1 (50%)      2 (40%)                                            
      Hyperplasia, Lymphoid                            1 (17%)                                                                      
      Pigmentation                                     3 (50%)      1 (50%)                                                         
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
      Hemorrhage                                      10 (20%)      6 (12%)      3 (6%)       4 (8%)                                
      Hyperplasia, Lymphoid                            9 (18%)     17 (34%)     15 (30%)     13 (26%)                               
      Pigmentation                                    42 (84%)     42 (84%)     33 (66%)     34 (68%)                               
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Fibrosis                                                                                2 (4%)                                
      Hematopoietic Cell Proliferation                34 (68%)     26 (52%)     29 (58%)     21 (42%)                               
      Infiltration Cellular, Mixed Cell                                                       1 (2%)                                
      Pigmentation                                    29 (58%)     34 (68%)     35 (70%)     36 (72%)                               
      Lymphoid Follicle, Atrophy                                                              4 (8%)                                
      Lymphoid Follicle, Hyperplasia                                                          1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)         (50)         (50)         (50)                                   
      Hyperplasia                                     43 (86%)     47 (94%)     48 (96%)     40 (80%)                               
      Hyperplasia, Lobular                             2 (4%)                                                                       
   Skin                                               (49)         (49)         (50)         (50)                                   
      Inflammation, Chronic                                                                   1 (2%)                                
      Subcutaneous Tissue, Edema                                                              1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Femur, Osteopetrosis                             2 (4%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression                                      7 (14%)     12 (24%)      6 (12%)      8 (16%)                               
      Hydrocephalus                                    3 (6%)       8 (16%)      2 (4%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS FEMALE                   0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Congestion                                       1 (2%)       2 (4%)       2 (4%)       7 (14%)                               
      Edema                                                         2 (4%)       3 (6%)       7 (14%)                               
      Foreign Body                                                  1 (2%)       1 (2%)                                             
      Hemorrhage                                                                 1 (2%)       4 (8%)                                
      Infiltration Cellular, Histiocyte               41 (82%)     41 (82%)     41 (82%)     43 (86%)                               
      Inflammation, Granulomatous                                   1 (2%)       1 (2%)                                             
      Metaplasia, Osseous                              1 (2%)       2 (4%)                                                          
      Alveolar Epithelium, Hyperplasia                 2 (4%)       6 (12%)      7 (14%)      5 (10%)                               
      Alveolar Epithelium, Hyperplasia, Multifocal     1 (2%)                                                                       
   Nose                                               (50)         (50)         (50)         (50)                                   
      Foreign Body                                     2 (4%)                    3 (6%)       2 (4%)                                
      Inflammation, Chronic                            4 (8%)       3 (6%)       4 (8%)       4 (8%)                                
      Respiratory Epithelium, Hyperplasia              3 (6%)       1 (2%)       3 (6%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)                       (3)          (1)                                    
      Cataract                                         1 (100%)                  3 (100%)     1 (100%)                              
      Retina, Degeneration                             1 (100%)                  3 (100%)     1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Cyst                                                          1 (2%)                    1 (2%)                                
      Hydronephrosis                                                                          2 (4%)                                
      Inflammation, Chronic                                         2 (4%)                                                          
      Nephropathy                                      2 (4%)       6 (12%)      6 (12%)      6 (12%)                               
      Renal Tubule, Cytoplasmic Alteration             3 (6%)       4 (8%)       5 (10%)      4 (8%)                                
      Renal Tubule, Dilatation                                                   1 (2%)                                             
      Renal Tubule, Infarct                                                                   1 (2%)                                
      Renal Tubule, Necrosis                                        1 (2%)                    2 (4%)                                
      Renal Tubule, Pigmentation                       4 (8%)       2 (4%)       3 (6%)       8 (16%)                               
      Transitional Epithelium, Hyperplasia                          1 (2%)       1 (2%)       1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Inflammation, Chronic                                         1 (2%)                                                          
      Transitional Epithelium, Hyperplasia                          1 (2%)                                                          
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                10           11           13           10                                     
    Dosing Accident                                    1            2            1            5                                     
    Natural Death                                      2            2            3            5                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                37           35           33           30                                     
                                                                                                                                    
  Animals Examined Microscopically                    50           50           50           50                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (50)         (49)         (48)         (50)                                   
      Hemorrhage                                                                              1 (2%)                                
      Perforation                                      1 (2%)       1 (2%)       1 (2%)                                             
   Intestine Large, Cecum                             (50)         (50)         (50)         (50)                                   
      Edema                                                                      1 (2%)                                             
   Liver                                              (50)         (50)         (50)         (50)                                   
      Basophilic Focus                                33 (66%)     32 (64%)     31 (62%)     23 (46%)                               
      Clear Cell Focus                                 7 (14%)      6 (12%)      8 (16%)      7 (14%)                               
      Degeneration, Cystic                             1 (2%)       1 (2%)                                                          
      Eosinophilic Focus                               4 (8%)       9 (18%)     10 (20%)      5 (10%)                               
      Hemorrhage                                       1 (2%)       1 (2%)                                                          
      Hepatodiaphragmatic Nodule                       2 (4%)       7 (14%)      3 (6%)       6 (12%)                               
      Infiltration Cellular, Mixed Cell                5 (10%)      2 (4%)       1 (2%)       3 (6%)                                
      Mixed Cell Focus                                 7 (14%)      7 (14%)     10 (20%)      2 (4%)                                
      Bile Duct, Hyperplasia                          25 (50%)     34 (68%)     39 (78%)     15 (30%)                               
      Centrilobular, Necrosis                          1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
      Hepatocyte, Vacuolization Cytoplasmic            1 (2%)       9 (18%)      6 (12%)      1 (2%)                                
      Kupffer Cell, Pigmentation                                    1 (2%)                    1 (2%)                                
   Mesentery                                          (13)         (8)          (19)         (17)                                   
      Accessory Spleen                                 2 (15%)      1 (13%)      1 (5%)       2 (12%)                               
      Hemorrhage                                       1 (8%)                                 1 (6%)                                
      Fat, Necrosis                                   11 (85%)      7 (88%)     17 (89%)     14 (82%)                               
   Oral Mucosa                                        (1)          (1)          (1)          (1)                                    
      Hyperplasia                                                   1 (100%)                                                        
   Pancreas                                           (50)         (50)         (50)         (50)                                   
      Atrophy                                         16 (32%)     14 (28%)      7 (14%)     13 (26%)                               
      Cyst                                             2 (4%)       3 (6%)       2 (4%)       2 (4%)                                
      Acinus, Cytoplasmic Alteration                   3 (6%)       2 (4%)       3 (6%)       2 (4%)                                
      Acinus, Hyperplasia, Focal                      17 (34%)     13 (26%)     18 (36%)     12 (24%)                               
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
   Salivary Glands                                    (50)         (50)         (50)         (50)                                   
      Atrophy                                          3 (6%)       1 (2%)                    1 (2%)                                
   Stomach, Forestomach                               (50)         (50)         (50)         (50)                                   
      Edema                                                         2 (4%)       2 (4%)                                             
      Erosion                                                                                 1 (2%)                                
      Inflammation, Chronic Active                                               1 (2%)       6 (12%)                               
      Ulcer                                            1 (2%)                                                                       
      Epithelium, Cyst                                                           1 (2%)       5 (10%)                               
      Epithelium, Hyperplasia                          3 (6%)      19 (38%)     42 (84%)     50 (100%)                              
   Stomach, Glandular                                 (50)         (50)         (50)         (50)                                   
      Edema                                                                      1 (2%)                                             
      Erosion                                          1 (2%)       1 (2%)                    2 (4%)                                
      Ulcer                                            1 (2%)       1 (2%)       1 (2%)                                             
   Tongue                                             (2)          (1)          (2)          (1)                                    
      Hyperplasia                                                                             1 (100%)                              
      Epithelium, Hyperplasia                          2 (100%)                  1 (50%)                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (50)         (50)         (50)                                   
      Cardiomyopathy                                  36 (72%)     40 (80%)     42 (84%)     40 (80%)                               
      Inflammation, Suppurative                                                               1 (2%)                                
      Thrombosis                                       1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (50)         (50)         (50)                                   
      Accessory Adrenal Cortical Nodule               18 (36%)     21 (42%)     17 (34%)     17 (34%)                               
      Angiectasis                                                   1 (2%)       1 (2%)       2 (4%)                                
      Degeneration, Fatty                             12 (24%)      8 (16%)     10 (20%)     11 (22%)                               
      Hyperplasia, Diffuse                             1 (2%)                    2 (4%)       1 (2%)                                
      Hyperplasia, Focal                               1 (2%)       2 (4%)       6 (12%)      6 (12%)                               
      Hypertrophy, Focal                               5 (10%)      3 (6%)       5 (10%)      8 (16%)                               
      Metaplasia, Osseous                                           1 (2%)                                                          
   Adrenal Medulla                                    (50)         (49)         (50)         (49)                                   
      Hyperplasia                                      7 (14%)     10 (20%)      6 (12%)      5 (10%)                               
   Islets, Pancreatic                                 (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      2 (4%)                                                                       
   Pituitary Gland                                    (50)         (50)         (50)         (50)                                   
      Cyst                                                                                    1 (2%)                                
      Pars Distalis, Angiectasis                       3 (6%)       4 (8%)       1 (2%)       1 (2%)                                
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Pars Distalis, Cyst                              4 (8%)       1 (2%)       6 (12%)      8 (16%)                               
      Pars Distalis, Hyperplasia                                                              2 (4%)                                
      Pars Distalis, Hyperplasia, Focal                8 (16%)      8 (16%)      9 (18%)      9 (18%)                               
      Pars Intermedia, Angiectasis                                               2 (4%)       2 (4%)                                
      Pars Intermedia, Cyst                                                      1 (2%)       4 (8%)                                
   Thyroid Gland                                      (50)         (50)         (50)         (50)                                   
      C-Cell, Hyperplasia                             26 (52%)     16 (32%)     18 (36%)     10 (20%)                               
      Follicle, Cyst                                   1 (2%)                    2 (4%)                                             
      Follicular Cell, Hyperplasia                                               1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (50)         (50)         (50)                                   
      Atypia Cellular                                 35 (70%)     36 (72%)     28 (56%)     37 (74%)                               
   Preputial Gland                                    (49)         (50)         (50)         (50)                                   
      Cyst                                             1 (2%)       1 (2%)       1 (2%)       2 (4%)                                
      Inflammation, Chronic                           21 (43%)     21 (42%)     31 (62%)     24 (48%)                               
   Prostate                                           (49)         (47)         (50)         (50)                                   
      Inflammation, Chronic                           15 (31%)     17 (36%)     17 (34%)     13 (26%)                               
      Epithelium, Hyperplasia                                                                 3 (6%)                                
      Epithelium, Ventral, Degeneration                3 (6%)                                 1 (2%)                                
      Epithelium, Ventral, Hyperplasia                12 (24%)      9 (19%)     11 (22%)     10 (20%)                               
      Ventral, Inflammation                            3 (6%)                                 1 (2%)                                
   Testes                                             (50)         (50)         (50)         (50)                                   
      Germinal Epithelium, Atrophy                     8 (16%)      9 (18%)     11 (22%)      5 (10%)                               
      Interstitial Cell, Hyperplasia                   8 (16%)      7 (14%)      7 (14%)      5 (10%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (50)         (50)         (50)                                   
      Hyperplasia                                      4 (8%)       3 (6%)       6 (12%)      4 (8%)                                
   Lymph Node                                         (21)         (27)         (29)         (28)                                   
      Deep Cervical, Hyperplasia, Lymphoid                                                    1 (4%)                                
      Iliac, Pigmentation                                           1 (4%)                                                          
      Mediastinal, Ectasia                             1 (5%)                                 1 (4%)                                
      Mediastinal, Hemorrhage                          3 (14%)      1 (4%)       4 (14%)                                            
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Mediastinal, Hyperplasia, Lymphoid               5 (24%)      4 (15%)      4 (14%)      4 (14%)                               
      Mediastinal, Pigmentation                        3 (14%)                   5 (17%)                                            
      Pancreatic, Ectasia                                                        1 (3%)       2 (7%)                                
      Pancreatic, Hemorrhage                           8 (38%)      9 (33%)     11 (38%)     11 (39%)                               
      Pancreatic, Hyperplasia, Lymphoid                8 (38%)     14 (52%)     15 (52%)     16 (57%)                               
      Pancreatic, Pigmentation                        12 (57%)     18 (67%)     22 (76%)     23 (82%)                               
   Lymph Node, Mandibular                             (8)          (1)          (3)          (2)                                    
      Ectasia                                          1 (13%)                   1 (33%)                                            
      Hyperplasia, Lymphoid                            1 (13%)                                                                      
   Lymph Node, Mesenteric                             (50)         (50)         (50)         (50)                                   
      Ectasia                                                       2 (4%)                    1 (2%)                                
      Hemorrhage                                      14 (28%)      8 (16%)      5 (10%)      4 (8%)                                
      Hyperplasia, Lymphoid                           16 (32%)      9 (18%)     22 (44%)     22 (44%)                               
      Pigmentation                                    43 (86%)     32 (64%)     31 (62%)     21 (42%)                               
   Spleen                                             (50)         (50)         (50)         (50)                                   
      Fibrosis                                         2 (4%)                    1 (2%)       1 (2%)                                
      Hematopoietic Cell Proliferation                20 (40%)     20 (40%)     22 (44%)     14 (28%)                               
      Pigmentation                                     7 (14%)      9 (18%)     18 (36%)     20 (40%)                               
      Lymphoid Follicle, Atrophy                                                              3 (6%)                                
      Lymphoid Follicle, Hyperplasia                                1 (2%)       1 (2%)       1 (2%)                                
   Thymus                                             (50)         (49)         (50)         (49)                                   
      Hemorrhage                                       1 (2%)       1 (2%)                    2 (4%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (48)         (45)         (46)         (44)                                   
      Cyst                                                                       1 (2%)                                             
      Hyperplasia                                     13 (27%)     12 (27%)     14 (30%)     10 (23%)                               
   Skin                                               (50)         (50)         (50)         (50)                                   
      Cyst Epithelial Inclusion                                                  2 (4%)       2 (4%)                                
      Foreign Body                                     1 (2%)                                                                       
      Granuloma                                                                  1 (2%)                                             
      Hyperkeratosis                                                                          1 (2%)                                
      Inflammation, Chronic                            1 (2%)                                                                       
      Necrosis                                         1 (2%)                                                                       
      Ulcer                                                                                   2 (4%)                                
      Epidermis, Hyperplasia                           1 (2%)                                 1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
MUSCULOSKELETAL SYSTEM - CONT                                                                                                       
      Cranium, Osteopetrosis                           1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)         (50)         (50)         (50)                                   
      Compression                                      7 (14%)      3 (6%)       6 (12%)      3 (6%)                                
      Hemorrhage                                       1 (2%)                    1 (2%)                                             
      Hydrocephalus                                    3 (6%)       2 (4%)       1 (2%)       3 (6%)                                
      Necrosis                                         1 (2%)                    1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Congestion                                       1 (2%)       1 (2%)       2 (4%)       3 (6%)                                
      Edema                                            3 (6%)       1 (2%)       1 (2%)       5 (10%)                               
      Foreign Body                                     1 (2%)                                                                       
      Hemorrhage                                       4 (8%)       3 (6%)       1 (2%)       4 (8%)                                
      Infiltration Cellular, Histiocyte               33 (66%)     25 (50%)     19 (38%)     27 (54%)                               
      Inflammation, Granulomatous                                                             1 (2%)                                
      Inflammation, Suppurative                                     1 (2%)                    1 (2%)                                
      Metaplasia, Osseous                              1 (2%)                    2 (4%)       1 (2%)                                
      Alveolar Epithelium, Hyperplasia                 7 (14%)      4 (8%)       5 (10%)      6 (12%)                               
      Alveolar Epithelium, Hyperplasia, Focal                                    1 (2%)                                             
   Nose                                               (50)         (50)         (50)         (50)                                   
      Foreign Body                                     5 (10%)      6 (12%)      5 (10%)      2 (4%)                                
      Inflammation, Chronic                            9 (18%)     10 (20%)     12 (24%)      8 (16%)                               
      Olfactory Epithelium, Atrophy                                                           2 (4%)                                
      Respiratory Epithelium, Hyperplasia              2 (4%)       7 (14%)      7 (14%)      1 (2%)                                
      Respiratory Epithelium, Metaplasia, Squamous                  3 (6%)       2 (4%)                                             
   Trachea                                            (50)         (50)         (50)         (50)                                   
      Epithelium, Hyperplasia                                       1 (2%)                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (1)          (2)                       (3)                                    
      Cataract                                         1 (100%)     2 (100%)                  2 (67%)                               
      Hemorrhage                                                                              1 (33%)                               
      Inflammation, Chronic                                                                   1 (33%)                               
      Retina, Degeneration                             1 (100%)     2 (100%)                  1 (33%)                               
   Harderian Gland                                                              (1)          (1)                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 93023-06         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                                           2,4-HEXADIENAL                                      Date: 03/14/01    
Route: GAVAGE                                                                                                     Time: 15:11:34    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         FISCHER 344 RATS MALE                     0            22.5         45           90                                        
                                                   MG/KG/DY     MG/KG/DY     MG/KG/DY     MG/KG/DY                                  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Pigmentation                                                               1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (50)         (50)         (50)                                   
      Cyst                                                                       1 (2%)       1 (2%)                                
      Glomerulosclerosis                                                                      1 (2%)                                
      Hydronephrosis                                   1 (2%)       1 (2%)                                                          
      Infarct                                                       1 (2%)                                                          
      Inflammation, Chronic                            3 (6%)       3 (6%)       2 (4%)       2 (4%)                                
      Nephropathy                                     28 (56%)     22 (44%)     19 (38%)     19 (38%)                               
      Renal Tubule, Cytoplasmic Alteration                                                    2 (4%)                                
      Renal Tubule, Dilatation                         1 (2%)       1 (2%)       2 (4%)                                             
      Renal Tubule, Necrosis                           1 (2%)       1 (2%)                                                          
      Renal Tubule, Pigmentation                                                 1 (2%)       3 (6%)                                
      Transitional Epithelium, Hyperplasia                          2 (4%)                    1 (2%)                                
   Urinary Bladder                                    (50)         (50)         (50)         (50)                                   
      Edema                                                         1 (2%)                                                          
      Hemorrhage                                       1 (2%)       2 (4%)                    1 (2%)                                
      Inflammation, Chronic                                         1 (2%)                                                          
      Inflammation, Suppurative                        1 (2%)                                                                       
      Transitional Epithelium, Hyperplasia                          2 (4%)                                                          
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------                                           
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.