Skip to Main Navigation
Skip to Page Content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Share This:
https://ntp.niehs.nih.gov/go/5314

TDMS Study 96007-03 Pathology Tables

NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03
Route: GAVAGE                                                                                                     Time: 08:37:05

                                                         FINAL # 3 RATS




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  1746-01-6

       Lock Date:  06/28/01

       Cage Range:  All

       Reasons For Removal:    25018 Dosing Accident                   25019 Moribund Sacrifice
                               25020 Natural Death                     25021 Terminal Sacrifice

       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: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          98           98           98           98           98           98           
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                19           27           15           19           17           17           
    Natural Death                                      9            6           10           15           14           15           
    Dosing Accident                                                              5                                                  
  Survivors                                                                                                                         
    Terminal Sacrifice                                25           21           23           19           22           21           
                                                                                                                                    
  Animals Examined Microscopically                    53           54           53           53           53           53           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (52)         (54)         (53)         (52)         (53)         (53)         
      Hemorrhage                                                                 1 (2%)                                             
      Perforation                                                                2 (4%)                                             
      Muscularis, Inflammation                         1 (2%)       2 (4%)       1 (2%)       1 (2%)       2 (4%)                   
      Periesophageal Tissue, Inflammation                                        3 (6%)                                             
   Intestine Large, Colon                             (52)         (53)         (53)         (53)         (53)         (51)         
      Parasite Metazoan                                1 (2%)       2 (4%)       1 (2%)                                 2 (4%)      
   Intestine Large, Rectum                            (52)         (54)         (53)         (52)         (53)         (53)         
      Parasite Metazoan                                6 (12%)      4 (7%)                                 2 (4%)       1 (2%)      
   Intestine Small, Duodenum                          (53)         (54)         (53)         (52)         (53)         (53)         
      Cyst                                                                                                              1 (2%)      
      Ulcer                                                         1 (2%)                                                          
      Epithelium, Hyperplasia                                                    1 (2%)                                             
   Liver                                              (53)         (54)         (53)         (53)         (53)         (53)         
      Angiectasis                                      2 (4%)       1 (2%)       1 (2%)                    3 (6%)       5 (9%)      
      Basophilic Focus                                 8 (15%)      6 (11%)      8 (15%)      7 (13%)      3 (6%)       3 (6%)      
      Basophilic Focus, Multiple                       4 (8%)       3 (6%)       5 (9%)       1 (2%)       2 (4%)       5 (9%)      
      Cholangiofibrosis                                1 (2%)       1 (2%)       2 (4%)       1 (2%)      11 (21%)     31 (58%)     
      Clear Cell Focus                                 4 (8%)       1 (2%)       1 (2%)       2 (4%)       1 (2%)       1 (2%)      
      Clear Cell Focus, Multiple                       1 (2%)                                 2 (4%)       1 (2%)       1 (2%)      
      Congestion                                       2 (4%)                                                           2 (4%)      
      Cytoplasmic Alteration                                                                                            2 (4%)      
      Degeneration, Cystic                                                                    2 (4%)                    4 (8%)      
      Eosinophilic Focus                               8 (15%)      6 (11%)      7 (13%)     10 (19%)      5 (9%)       2 (4%)      
      Eosinophilic Focus, Multiple                     3 (6%)       8 (15%)     14 (26%)     17 (32%)     22 (42%)     42 (79%)     
      Fatty Change, Diffuse                                         2 (4%)      12 (23%)     17 (32%)     30 (57%)     48 (91%)     
      Fatty Change, Focal                              2 (4%)       6 (11%)      4 (8%)       4 (8%)       1 (2%)       2 (4%)      
      Hematopoietic Cell Proliferation                 1 (2%)       2 (4%)       2 (4%)       4 (8%)       2 (4%)       2 (4%)      
      Hemorrhage                                                                                           1 (2%)                   
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    2                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Hepatodiaphragmatic Nodule                                    2 (4%)                    1 (2%)       2 (4%)                   
      Hyperplasia, Nodular                                                                    3 (6%)       7 (13%)     36 (68%)     
      Inflammation                                    33 (62%)     46 (85%)     47 (89%)     50 (94%)     52 (98%)     49 (92%)     
      Mitotic Alteration                                                                      1 (2%)       1 (2%)                   
      Mixed Cell Focus                                 4 (8%)       8 (15%)      8 (15%)                   2 (4%)       4 (8%)      
      Mixed Cell Focus, Multiple                      26 (49%)     11 (20%)     21 (40%)     23 (43%)     28 (53%)     17 (32%)     
      Necrosis                                         1 (2%)       4 (7%)       4 (8%)       8 (15%)     10 (19%)     17 (32%)     
      Pigmentation                                     4 (8%)       9 (17%)     34 (64%)     48 (91%)     52 (98%)     53 (100%)    
      Thrombosis                                                                                                        1 (2%)      
      Toxic Hepatopathy                                             2 (4%)       8 (15%)     30 (57%)     45 (85%)     53 (100%)    
      Artery, Inflammation, Chronic Active                                                                              2 (4%)      
      Bile Duct, Cyst                                  3 (6%)       1 (2%)       2 (4%)       2 (4%)                   21 (40%)     
      Bile Duct, Fibrosis                                           2 (4%)                    1 (2%)       3 (6%)       4 (8%)      
      Bile Duct, Hyperplasia                           5 (9%)       4 (7%)       7 (13%)     22 (42%)     40 (75%)     53 (100%)    
      Centrilobular, Degeneration                      2 (4%)       2 (4%)                    4 (8%)       3 (6%)       5 (9%)      
      Hepatocyte, Hypertrophy                                      19 (35%)     19 (36%)     42 (79%)     41 (77%)     52 (98%)     
      Hepatocyte, Multinucleated                                                16 (30%)     26 (49%)     36 (68%)     51 (96%)     
      Hepatocyte, Centrilobular, Atrophy                                                                   1 (2%)                   
      Oval Cell, Hyperplasia                                        4 (7%)       3 (6%)      20 (38%)     38 (72%)     53 (100%)    
      Portal, Fibrosis                                                                                     5 (9%)      27 (51%)     
   Mesentery                                          (2)          (2)                       (1)          (6)          (8)          
      Metaplasia, Osseous                              1 (50%)                                                                      
      Artery, Inflammation, Chronic Active                          1 (50%)                                4 (67%)      7 (88%)     
      Fat, Necrosis                                                 1 (50%)                   1 (100%)     1 (17%)      1 (13%)     
      Vein, Thrombosis                                 1 (50%)                                                                      
   Oral Mucosa                                        (2)          (9)          (16)         (16)         (22)         (29)         
      Gingival, Hyperplasia, Squamous                  1 (50%)      7 (78%)     14 (88%)     13 (81%)     15 (68%)     16 (55%)     
   Pancreas                                           (51)         (54)         (52)         (53)         (52)         (51)         
      Hemorrhage                                                                                                        1 (2%)      
      Inflammation, Acute                                                                     1 (2%)                                
      Inflammation, Chronic Active                                               2 (4%)       2 (4%)       3 (6%)       6 (12%)     
      Necrosis                                                                                1 (2%)                    1 (2%)      
      Acinus, Atrophy                                  1 (2%)       2 (4%)       4 (8%)       4 (8%)       4 (8%)       9 (18%)     
      Acinus, Hyperplasia                              2 (4%)                                 1 (2%)       2 (4%)                   
      Acinus, Vacuolization Cytoplasmic                1 (2%)                                 1 (2%)      15 (29%)     42 (82%)     
      Artery, Inflammation, Chronic Active                          1 (2%)       1 (2%)       2 (4%)       2 (4%)       7 (14%)     
   Salivary Glands                                    (51)         (54)         (52)         (50)         (51)         (52)         
      Atrophy                                                                                 2 (4%)       1 (2%)                   
      Inflammation                                                               2 (4%)       3 (6%)                    1 (2%)      
      Mineralization                                   1 (2%)                                                                       
   Stomach, Forestomach                               (53)         (54)         (53)         (53)         (53)         (53)         
      Cyst, Squamous                                                             1 (2%)                                             
      Edema                                                                                   1 (2%)                    1 (2%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    3                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Erosion                                                                    1 (2%)                    1 (2%)                   
      Hyperkeratosis                                   1 (2%)       1 (2%)       1 (2%)       1 (2%)       2 (4%)       3 (6%)      
      Hyperplasia, Squamous                            3 (6%)       4 (7%)       4 (8%)       2 (4%)       7 (13%)     11 (21%)     
      Inflammation                                     1 (2%)       1 (2%)       2 (4%)                    2 (4%)       5 (9%)      
      Mineralization                                                             1 (2%)                                             
      Necrosis                                                                                                          1 (2%)      
      Ulcer                                            2 (4%)       1 (2%)                    1 (2%)       1 (2%)       4 (8%)      
   Stomach, Glandular                                 (53)         (54)         (53)         (53)         (53)         (53)         
      Diverticulum                                                               1 (2%)                                             
      Erosion                                          1 (2%)                                                                       
      Metaplasia                                                                                           1 (2%)                   
      Mineralization                                   3 (6%)                                 1 (2%)       3 (6%)                   
      Ulcer                                                                                                             2 (4%)      
   Tooth                                              (16)         (16)         (12)         (13)         (14)         (18)         
      Peridontal Tissue, Fibrosis                      1 (6%)                                                                       
      Peridontal Tissue, Inflammation                 15 (94%)     16 (100%)    12 (100%)    13 (100%)    14 (100%)    18 (100%)    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Blood Vessel                                       (53)         (54)         (53)         (53)         (53)         (53)         
      Thrombosis                                                                 1 (2%)                                             
      Aorta, Mineralization                            1 (2%)       1 (2%)                                 1 (2%)                   
   Heart                                              (53)         (54)         (53)         (52)         (53)         (52)         
      Cardiomyopathy                                  10 (19%)     12 (22%)     22 (42%)     25 (48%)     32 (60%)     36 (69%)     
      Mineralization                                   1 (2%)                                              1 (2%)                   
      Artery, Inflammation                                                                                              1 (2%)      
      Artery, Mineralization                                        1 (2%)                                                          
      Artery, Thrombosis                                                                                                1 (2%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (53)         (54)         (53)         (53)         (53)         (53)         
      Angiectasis                                     11 (21%)     21 (39%)     18 (34%)     17 (32%)     17 (32%)     11 (21%)     
      Atrophy                                          2 (4%)                    4 (8%)       5 (9%)       5 (9%)      27 (51%)     
      Degeneration, Cystic                            11 (21%)     15 (28%)     21 (40%)     18 (34%)     17 (32%)     17 (32%)     
      Hyperplasia                                     16 (30%)     16 (30%)     18 (34%)     25 (47%)     29 (55%)     30 (57%)     
      Hypertrophy                                     41 (77%)     43 (80%)     46 (87%)     40 (75%)     45 (85%)     47 (89%)     
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Inflammation, Suppurative                        1 (2%)                                                                       
      Mineralization                                                                                                    1 (2%)      
      Necrosis                                                      1 (2%)       2 (4%)       1 (2%)       3 (6%)       1 (2%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    4                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - CONT                                                                                                             
      Thrombosis                                                                              1 (2%)                                
      Vacuolization Cytoplasmic                       11 (21%)      7 (13%)     12 (23%)     21 (40%)     18 (34%)     15 (28%)     
   Adrenal Medulla                                    (53)         (54)         (53)         (53)         (53)         (53)         
      Angiectasis                                                   1 (2%)       2 (4%)       1 (2%)                                
      Hyperplasia                                     19 (36%)     10 (19%)     18 (34%)      7 (13%)     10 (19%)      9 (17%)     
      Inflammation, Suppurative                                                               1 (2%)                                
   Islets, Pancreatic                                 (51)         (54)         (53)         (53)         (52)         (52)         
      Hyperplasia                                                                1 (2%)       1 (2%)                                
   Parathyroid Gland                                  (46)         (47)         (47)         (44)         (45)         (45)         
      Fibrosis                                                                   1 (2%)                                             
      Hyperplasia                                      1 (2%)                                                                       
   Pituitary Gland                                    (53)         (54)         (52)         (53)         (53)         (52)         
      Angiectasis                                     25 (47%)     18 (33%)     25 (48%)     20 (38%)     21 (40%)      9 (17%)     
      Atypia Cellular                                  1 (2%)                                                                       
      Cyst                                             1 (2%)       1 (2%)                                              1 (2%)      
      Cytoplasmic Alteration                           1 (2%)                    1 (2%)       4 (8%)       3 (6%)                   
      Developmental Malformation                       1 (2%)                                                                       
      Inflammation, Chronic                                                                                             1 (2%)      
      Vacuolization Cytoplasmic                                     3 (6%)       1 (2%)       2 (4%)       2 (4%)                   
      Pars Distalis, Hyperplasia                      19 (36%)     19 (35%)     16 (31%)     21 (40%)     26 (49%)     19 (37%)     
      Pars Intermedia, Hyperplasia                     2 (4%)                                              1 (2%)       1 (2%)      
   Thyroid Gland                                      (52)         (54)         (53)         (51)         (53)         (52)         
      Angiectasis                                                   1 (2%)       1 (2%)       1 (2%)       4 (8%)       1 (2%)      
      Cyst                                             1 (2%)                                 1 (2%)                    1 (2%)      
      Inflammation, Chronic Active                                               1 (2%)                                             
      Inflammation, Suppurative                                                  1 (2%)                                             
      C-Cell, Hyperplasia                             19 (37%)     17 (31%)     22 (42%)     19 (37%)     16 (30%)     23 (44%)     
      Follicular Cell, Hyperplasia                     2 (4%)       2 (4%)                                                          
      Follicular Cell, Hypertrophy                     3 (6%)       4 (7%)       4 (8%)       7 (14%)     10 (19%)     17 (33%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (50)         (52)         (53)         (52)         (51)         (53)         
      Hyperplasia, Basal Cell                          1 (2%)                    1 (2%)                                             
      Inflammation                                    41 (82%)     40 (77%)     35 (66%)     34 (65%)     28 (55%)     26 (49%)     
      Duct, Cyst                                      34 (68%)     37 (71%)     41 (77%)     42 (81%)     41 (80%)     48 (91%)     
   Ovary                                              (51)         (53)         (53)         (53)         (53)         (53)         
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    5                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
      Atrophy                                         49 (96%)     46 (87%)     50 (94%)     44 (83%)     50 (94%)     31 (58%)     
      Congestion                                                                              1 (2%)                                
      Cyst                                            14 (27%)     16 (30%)     13 (25%)     15 (28%)     14 (26%)     13 (25%)     
      Fibrosis                                                                   1 (2%)                    1 (2%)                   
      Inflammation, Chronic Active                                                            1 (2%)                    1 (2%)      
      Inflammation, Suppurative                                                               1 (2%)       1 (2%)                   
      Artery, Inflammation, Chronic Active                                                                              1 (2%)      
      Corpus Luteum, Cyst                                           1 (2%)                                                          
      Periovarian Tissue, Inflammation, Suppurative                                           1 (2%)                                
   Oviduct                                            (2)          (1)          (2)                       (1)          (1)          
      Inflammation                                     2 (100%)     1 (100%)     1 (50%)                                1 (100%)    
      Necrosis                                                                                             1 (100%)                 
      Epithelium, Hyperplasia                                                    1 (50%)                                            
   Uterus                                             (52)         (53)         (53)         (53)         (53)         (53)         
      Adenomyosis                                                                                          1 (2%)                   
      Cyst                                                                                                              1 (2%)      
      Hemorrhage                                       1 (2%)                                                           1 (2%)      
      Inflammation, Chronic Active                                  2 (4%)       3 (6%)                    3 (6%)       1 (2%)      
      Inflammation, Suppurative                        7 (13%)      6 (11%)     12 (23%)      9 (17%)     11 (21%)      5 (9%)      
      Metaplasia, Squamous                            29 (56%)     31 (58%)     28 (53%)     23 (43%)     32 (60%)     17 (32%)     
      Necrosis                                                                                1 (2%)                                
      Ulcer                                                                      1 (2%)                                             
      Cervix, Hyperplasia, Stromal                                  1 (2%)       1 (2%)       1 (2%)       1 (2%)                   
      Cervix, Inflammation, Suppurative                                                                    1 (2%)                   
      Endometrium, Adenomyosis                                                   1 (2%)                                             
      Endometrium, Hyperplasia, Cystic                30 (58%)     33 (62%)     35 (66%)     27 (51%)     31 (58%)     19 (36%)     
      Epithelium, Hyperplasia                                                                 1 (2%)                                
      Serosa, Inflammation, Chronic Active                                       1 (2%)                                             
   Vagina                                                          (1)          (1)          (3)          (3)          (1)          
      Cyst                                                                       1 (100%)                  1 (33%)                  
      Hyperplasia, Stromal                                          1 (100%)                                                        
      Inflammation                                                                            2 (67%)                               
      Necrosis                                                                                1 (33%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (53)         (54)         (53)         (53)         (53)         (53)         
      Atrophy                                                                                                           1 (2%)      
      Hyperplasia                                     36 (68%)     41 (76%)     32 (60%)     35 (66%)     37 (70%)     43 (81%)     
   Lymph Node                                         (2)          (6)          (3)          (5)          (6)          (9)          
      Deep Cervical, Hemorrhage                                                               1 (20%)                               
      Inguinal, Ectasia                                                                                    1 (17%)                  
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    6                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - CONT                                                                                                         
      Lumbar, Ectasia                                  1 (50%)      2 (33%)      1 (33%)      2 (40%)                               
      Lumbar, Hemorrhage                                                                      1 (20%)                               
      Lumbar, Hyperplasia, Plasma Cell                              2 (33%)                   1 (20%)                               
      Lumbar, Pigmentation                                                                    1 (20%)                               
      Mediastinal, Congestion                                                                              1 (17%)                  
      Mediastinal, Ectasia                                                                                 1 (17%)      3 (33%)     
      Mediastinal, Hemorrhage                                       1 (17%)                   1 (20%)                   5 (56%)     
      Mediastinal, Hyperplasia                                                                             1 (17%)                  
      Mediastinal, Hyperplasia, Histiocytic                                      1 (33%)                   1 (17%)      1 (11%)     
      Mediastinal, Hyperplasia, Lymphoid                            1 (17%)                                                         
      Mediastinal, Hyperplasia, Plasma Cell                                                   1 (20%)                               
      Mediastinal, Pigmentation                                                  1 (33%)                                1 (11%)     
      Renal, Ectasia                                                1 (17%)                                                         
      Renal, Hyperplasia, Histiocytic                               1 (17%)                                                         
   Lymph Node, Mandibular                             (51)         (54)         (52)         (50)         (51)         (52)         
      Congestion                                       1 (2%)                                                                       
      Ectasia                                                                                              1 (2%)       6 (12%)     
      Hyperplasia, Lymphoid                                         3 (6%)       3 (6%)                                 2 (4%)      
      Hyperplasia, Plasma Cell                        25 (49%)     31 (57%)     23 (44%)     22 (44%)     15 (29%)     16 (31%)     
      Inflammation, Suppurative                                                                                         1 (2%)      
   Lymph Node, Mesenteric                             (52)         (53)         (53)         (53)         (53)         (51)         
      Atrophy                                                       1 (2%)                    1 (2%)                                
      Ectasia                                                                                                           1 (2%)      
      Hemorrhage                                                                                           1 (2%)                   
      Hyperplasia, Histiocytic                         1 (2%)                                              1 (2%)       2 (4%)      
      Hyperplasia, Plasma Cell                                                                             1 (2%)                   
   Spleen                                             (51)         (54)         (53)         (53)         (52)         (52)         
      Hematopoietic Cell Proliferation                46 (90%)     50 (93%)     38 (72%)     42 (79%)     44 (85%)     43 (83%)     
      Hyperplasia, Lymphoid                            1 (2%)                                                           4 (8%)      
      Necrosis                                                                   1 (2%)                                             
      Pigmentation                                    45 (88%)     49 (91%)     49 (92%)     51 (96%)     49 (94%)     47 (90%)     
      Lymphoid Follicle, Atrophy                       4 (8%)                    1 (2%)                    1 (2%)       1 (2%)      
   Thymus                                             (51)         (52)         (52)         (49)         (46)         (42)         
      Atrophy                                         36 (71%)     41 (79%)     44 (85%)     41 (84%)     44 (96%)     42 (100%)    
      Cyst                                                                                                 1 (2%)       1 (2%)      
      Hemorrhage                                       1 (2%)                    1 (2%)                                             
      Inflammation, Chronic Active                                                                         1 (2%)                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (53)         (54)         (53)         (53)         (53)         (53)         
      Cyst                                             4 (8%)       3 (6%)                    1 (2%)       1 (2%)       1 (2%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    7                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - CONT                                                                                                         
      Hyperplasia                                     25 (47%)     21 (39%)     24 (45%)     22 (42%)     18 (34%)     16 (30%)     
      Inflammation, Chronic Active                                                                         1 (2%)                   
      Inflammation, Granulomatous                      1 (2%)       1 (2%)       1 (2%)                                 1 (2%)      
   Skin                                               (53)         (54)         (53)         (53)         (53)         (53)         
      Cyst Epithelial Inclusion                        1 (2%)                                                           2 (4%)      
      Hemorrhage                                                                 1 (2%)                                             
      Hyperplasia, Squamous                                                      1 (2%)                    1 (2%)                   
      Inflammation, Chronic Active                                               2 (4%)                                 1 (2%)      
      Necrosis                                                                   1 (2%)                                             
      Ulcer                                                                      1 (2%)                    1 (2%)                   
      Epidermis, Inflammation                                                                                           1 (2%)      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (53)         (54)         (53)         (53)         (53)         (53)         
      Fracture                                                                                                          1 (2%)      
      Maxilla, Inflammation, Focal, Suppurative                     1 (2%)                                                          
   Skeletal Muscle                                                              (1)          (2)                                    
      Hemorrhage                                                                              1 (50%)                               
      Inflammation, Chronic Active                                                            1 (50%)                               
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (53)         (54)         (53)         (53)         (53)         (53)         
      Hemorrhage                                                                 1 (2%)                                             
      Hydrocephalus                                                 1 (2%)       1 (2%)                                             
      Inflammation, Suppurative                                                                            1 (2%)                   
      Mineralization                                                1 (2%)       1 (2%)                    2 (4%)       2 (4%)      
      Vacuolization Cytoplasmic, Focal                                           1 (2%)                                             
      Artery, Thrombosis                                                                                   1 (2%)                   
      Cerebellum, Developmental Malformation           1 (2%)                                                                       
      Cerebellum, Necrosis                                                       1 (2%)                                             
      Glial Cell, Hyperplasia                                       1 (2%)                                              1 (2%)      
   Spinal Cord                                                                  (1)                                                 
      Gliosis                                                                    1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (53)         (54)         (53)         (52)         (53)         (52)         
      Congestion                                                                 2 (4%)                                             
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    8                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - CONT                                                                                                           
      Edema                                                                      2 (4%)                    1 (2%)                   
      Hemorrhage                                                    1 (2%)                                              2 (4%)      
      Infiltration Cellular, Histiocyte               41 (77%)     46 (85%)     43 (81%)     43 (83%)     49 (92%)     50 (96%)     
      Inflammation, Chronic Active                                                                                      1 (2%)      
      Inflammation, Granulomatous                      2 (4%)       1 (2%)       2 (4%)       2 (4%)                                
      Inflammation, Suppurative                        1 (2%)                                 2 (4%)                                
      Metaplasia, Squamous                             1 (2%)                                              5 (9%)       6 (12%)     
      Mineralization                                   1 (2%)                                              1 (2%)       1 (2%)      
      Necrosis                                                                                1 (2%)                    1 (2%)      
      Pigmentation                                                  1 (2%)                                                          
      Alveolar Epithelium, Hyperplasia                12 (23%)                                                                      
      Alveolar Epithelium, Metaplasia, Bronchiolar     2 (4%)      19 (35%)     33 (62%)     35 (67%)     45 (85%)     46 (88%)     
      Bronchiole, Dilatation                                                     1 (2%)                                             
      Serosa, Inflammation, Focal, Suppurative                                                1 (2%)                                
   Nose                                               (53)         (54)         (53)         (53)         (53)         (53)         
      Cyst, Squamous                                                                                       1 (2%)                   
      Inflammation                                     2 (4%)                                 3 (6%)       5 (9%)       4 (8%)      
      Goblet Cell, Septum, Hyperplasia                                                                     1 (2%)                   
      Nasolacrimal Duct, Inflammation                  2 (4%)                                                                       
      Nasolacrimal Duct, Respiratory Epithelium,                                                                                    
         Hyperplasia                                                                                       1 (2%)                   
      Nasopharyngeal Duct, Inflammation                                                       1 (2%)                    1 (2%)      
      Nasopharyngeal Duct, Necrosis                                                           1 (2%)                                
      Olfactory Epithelium, Degeneration                                                                   1 (2%)                   
      Olfactory Epithelium, Inflammation                                                                   1 (2%)       1 (2%)      
      Respiratory Epithelium, Cyst                                                                         2 (4%)                   
      Respiratory Epithelium, Hyperplasia                                                     1 (2%)       2 (4%)                   
      Septum, Hyperplasia, Squamous                                                                                     1 (2%)      
      Septum, Inflammation                                                                                              2 (4%)      
      Squamous Epithelium, Inflammation,                                                                                            
        Suppurative                                    1 (2%)                                                                       
      Turbinate, Hyperplasia, Squamous                                                                                  1 (2%)      
      Turbinate, Septum, Inflammation                                            1 (2%)       1 (2%)                    2 (4%)      
      Turbinate, Respiratory Epithelium,                                                                                            
        Hyperplasia                                                              1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (53)         (54)         (53)         (52)         (53)         (53)         
      Degeneration                                     1 (2%)                                                                       
      Hemorrhage                                       1 (2%)                                                                       
      Anterior Chamber, Inflammation, Suppurative                                                                       1 (2%)      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page    9                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                0 NG/KG      3 NG/KG      10 NG/KG     22 NG/KG     46 NG/KG     100             
                                                                                                                    NG/KG           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
SPECIAL SENSES SYSTEM - CONT                                                                                                        
      Cornea, Inflammation, Suppurative                                          1 (2%)                                 1 (2%)      
      Lens, Degeneration                                                                                   1 (2%)                   
      Retina, Atrophy                                  5 (9%)       5 (9%)       5 (9%)       3 (6%)       4 (8%)       6 (11%)     
      Retina, Degeneration                                                                                 1 (2%)                   
   Harderian Gland                                    (53)         (54)         (53)         (52)         (53)         (53)         
      Atrophy, Focal                                   1 (2%)                                                                       
      Inflammation                                    12 (23%)      3 (6%)       2 (4%)       2 (4%)       8 (15%)      6 (11%)     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (53)         (54)         (53)         (53)         (53)         (53)         
      Calculus Gross Observation                                                                                        1 (2%)      
      Calculus Micro Observation Only                  1 (2%)       1 (2%)       1 (2%)       3 (6%)       2 (4%)                   
      Casts Protein                                    3 (6%)       5 (9%)       2 (4%)                    1 (2%)       1 (2%)      
      Cyst                                             2 (4%)                                              1 (2%)       1 (2%)      
      Fibrosis                                                      1 (2%)                                                          
      Infarct                                                                    1 (2%)                                             
      Inflammation, Chronic Active                     5 (9%)       1 (2%)                    1 (2%)       1 (2%)                   
      Inflammation, Suppurative                                                  2 (4%)       1 (2%)       1 (2%)       2 (4%)      
      Mineralization                                  40 (75%)     39 (72%)     30 (57%)     32 (60%)     42 (79%)     42 (79%)     
      Necrosis                                                                                1 (2%)       1 (2%)                   
      Nephropathy                                     34 (64%)     26 (48%)     32 (60%)     36 (68%)     39 (74%)     52 (98%)     
      Papilla, Necrosis                                                          1 (2%)                                             
      Pelvis, Dilatation                               2 (4%)       1 (2%)       1 (2%)                    2 (4%)                   
      Pelvis, Inflammation                             2 (4%)       1 (2%)       1 (2%)       1 (2%)       4 (8%)       2 (4%)      
      Renal Tubule, Degeneration                                                                                        1 (2%)      
      Transitional Epithelium, Hyperplasia             3 (6%)       6 (11%)      8 (15%)      8 (15%)     11 (21%)     11 (21%)     
   Ureter                                             (1)                                                                           
      Inflammation                                     1 (100%)                                                                     
      Transitional Epithelium, Hyperplasia             1 (100%)                                                                     
   Urinary Bladder                                    (52)         (53)         (53)         (52)         (53)         (53)         
      Calculus Micro Observation Only                               1 (2%)                                                          
      Hemorrhage                                                    1 (2%)                                                          
      Inflammation                                     6 (12%)     10 (19%)      4 (8%)                    8 (15%)      3 (6%)      
      Metaplasia, Squamous                                                                                              1 (2%)      
      Transitional Epithelium, Hyperplasia             1 (2%)       2 (4%)       1 (2%)                    6 (11%)      2 (4%)      
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   10                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially In Study                          50                                                                            
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                16                                                                            
    Natural Death                                     13                                                                            
  Survivors                                                                                                                         
    Terminal Sacrifice                                21                                                                            
                                                                                                                                    
  Animals Examined Microscopically                    50                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (49)                                                                          
      Parasite Metazoan                                1 (2%)                                                                       
   Intestine Large, Rectum                            (50)                                                                          
      Parasite Metazoan                                5 (10%)                                                                      
   Intestine Small, Jejunum                           (50)                                                                          
      Inflammation, Chronic                            1 (2%)                                                                       
   Liver                                              (50)                                                                          
      Angiectasis                                      4 (8%)                                                                       
      Atypia Cellular                                  1 (2%)                                                                       
      Basophilic Focus                                 7 (14%)                                                                      
      Basophilic Focus, Multiple                       9 (18%)                                                                      
      Cholangiofibrosis                                1 (2%)                                                                       
      Clear Cell Focus                                 6 (12%)                                                                      
      Clear Cell Focus, Multiple                       2 (4%)                                                                       
      Cytoplasmic Alteration                           1 (2%)                                                                       
      Eosinophilic Focus                               6 (12%)                                                                      
      Eosinophilic Focus, Multiple                    21 (42%)                                                                      
      Fatty Change, Diffuse                           10 (20%)                                                                      
      Fatty Change, Focal                              8 (16%)                                                                      
      Hematopoietic Cell Proliferation                 2 (4%)                                                                       
      Hepatodiaphragmatic Nodule                       1 (2%)                                                                       
      Inflammation                                    43 (86%)                                                                      
      Mixed Cell Focus                                 1 (2%)                                                                       
      Mixed Cell Focus, Multiple                      28 (56%)                                                                      
      Necrosis                                         8 (16%)                                                                      
      Pigmentation                                    45 (90%)                                                                      
      Toxic Hepatopathy                               16 (32%)                                                                      
      Vacuolization Cytoplasmic                        1 (2%)                                                                       
      Bile Duct, Cyst                                  6 (12%)                                                                      
      Bile Duct, Fibrosis                              5 (10%)                                                                      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   11                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - CONT                                                                                                            
      Bile Duct, Hyperplasia                           7 (14%)                                                                      
      Hepatocyte, Hypertrophy                         22 (44%)                                                                      
      Hepatocyte, Multinucleated                      32 (64%)                                                                      
      Oval Cell, Hyperplasia                           1 (2%)                                                                       
      Portal, Fibrosis                                 1 (2%)                                                                       
      Serosa, Inflammation, Chronic Active             1 (2%)                                                                       
   Mesentery                                          (1)                                                                           
      Artery, Inflammation, Chronic Active             1 (100%)                                                                     
   Oral Mucosa                                        (11)                                                                          
      Gingival, Hyperplasia, Squamous                  8 (73%)                                                                      
   Pancreas                                           (49)                                                                          
      Angiectasis                                      1 (2%)                                                                       
      Basophilic Focus                                 1 (2%)                                                                       
      Inflammation, Chronic Active                     4 (8%)                                                                       
      Acinus, Atrophy                                  4 (8%)                                                                       
      Artery, Inflammation, Chronic Active             2 (4%)                                                                       
   Salivary Glands                                    (49)                                                                          
      Atrophy                                          2 (4%)                                                                       
      Fibrosis                                         1 (2%)                                                                       
      Inflammation                                     1 (2%)                                                                       
   Stomach, Forestomach                               (50)                                                                          
      Hyperkeratosis                                   1 (2%)                                                                       
      Hyperplasia, Squamous                            5 (10%)                                                                      
      Inflammation                                     4 (8%)                                                                       
      Ulcer                                            4 (8%)                                                                       
   Stomach, Glandular                                 (50)                                                                          
      Erosion                                          1 (2%)                                                                       
   Tongue                                             (1)                                                                           
      Inflammation, Chronic Active                     1 (100%)                                                                     
   Tooth                                              (12)                                                                          
      Peridontal Tissue, Inflammation                 12 (100%)                                                                     
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)                                                                          
      Cardiomyopathy                                  22 (44%)                                                                      
      Inflammation                                     1 (2%)                                                                       
      Atrium, Thrombosis                               2 (4%)                                                                       
      Epicardium, Inflammation, Chronic Active         1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                             Page   12                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)                                                                          
      Angiectasis                                     15 (30%)                                                                      
      Atrophy                                          4 (8%)                                                                       
      Degeneration, Cystic                            17 (34%)                                                                      
      Hyperplasia                                     20 (40%)                                                                      
      Hypertrophy                                     46 (92%)                                                                      
      Necrosis                                         3 (6%)                                                                       
      Vacuolization Cytoplasmic                       13 (26%)                                                                      
   Adrenal Medulla                                    (50)                                                                          
      Hyperplasia                                     15 (30%)                                                                      
   Islets, Pancreatic                                 (49)                                                                          
      Hyperplasia                                      1 (2%)                                                                       
   Pituitary Gland                                    (50)                                                                          
      Angiectasis                                     15 (30%)                                                                      
      Cytoplasmic Alteration                           1 (2%)                                                                       
      Vacuolization Cytoplasmic                        3 (6%)                                                                       
      Pars Distalis, Hyperplasia                      18 (36%)                                                                      
   Thyroid Gland                                      (49)                                                                          
      Angiectasis                                      1 (2%)                                                                       
      C-Cell, Hyperplasia                             15 (31%)                                                                      
      Follicular Cell, Hypertrophy                     6 (12%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (49)                                                                          
      Atrophy                                          1 (2%)                                                                       
      Hyperplasia, Basal Cell                          1 (2%)                                                                       
      Hyperplasia, Squamous                            1 (2%)                                                                       
      Inflammation                                    35 (71%)                                                                      
      Duct, Cyst                                      35 (71%)                                                                      
   Ovary                                              (49)                                                                          
      Atrophy                                         45 (92%)                                                                      
      Cyst                                            16 (33%)                                                                      
      Inflammation, Granulomatous                      1 (2%)                                                                       
   Oviduct                                            (2)                                                                           
      Inflammation                                     2 (100%)                                                                     
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   13                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - CONT                                                                                                               
   Uterus                                             (50)                                                                          
      Inflammation, Chronic Active                     1 (2%)                                                                       
      Inflammation, Suppurative                        9 (18%)                                                                      
      Metaplasia, Squamous                            33 (66%)                                                                      
      Cervix, Inflammation, Chronic Active             1 (2%)                                                                       
      Endometrium, Hyperplasia, Cystic                32 (64%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)                                                                          
      Atrophy                                          1 (2%)                                                                       
      Hyperplasia                                     36 (72%)                                                                      
      Myelofibrosis                                    1 (2%)                                                                       
   Lymph Node                                         (5)                                                                           
      Lumbar, Ectasia                                  2 (40%)                                                                      
      Lumbar, Hyperplasia, Plasma Cell                 2 (40%)                                                                      
      Mediastinal, Hemorrhage                          1 (20%)                                                                      
      Mediastinal, Hyperplasia, Plasma Cell            1 (20%)                                                                      
   Lymph Node, Mandibular                             (49)                                                                          
      Ectasia                                          2 (4%)                                                                       
      Hyperplasia, Lymphoid                            2 (4%)                                                                       
      Hyperplasia, Plasma Cell                        30 (61%)                                                                      
   Lymph Node, Mesenteric                             (49)                                                                          
      Hyperplasia, Histiocytic                         1 (2%)                                                                       
   Spleen                                             (49)                                                                          
      Hematopoietic Cell Proliferation                42 (86%)                                                                      
      Hyperplasia, Lymphoid                            1 (2%)                                                                       
      Pigmentation                                    42 (86%)                                                                      
      Lymphoid Follicle, Atrophy                       1 (2%)                                                                       
      Red Pulp, Atrophy                                1 (2%)                                                                       
   Thymus                                             (49)                                                                          
      Atrophy                                         45 (92%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (50)                                                                          
      Cyst                                             4 (8%)                                                                       
      Hyperplasia                                     19 (38%)                                                                      
   Skin                                               (50)                                                                          
      Ulcer                                            1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   14                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (50)                                                                          
      Hemorrhage                                       1 (2%)                                                                       
      Inflammation, Suppurative                        1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)                                                                          
      Infiltration Cellular, Histiocyte               41 (82%)                                                                      
      Inflammation, Suppurative                        1 (2%)                                                                       
      Metaplasia, Squamous                             3 (6%)                                                                       
      Alveolar Epithelium, Metaplasia, Bronchiolar    31 (62%)                                                                      
      Serosa, Inflammation, Suppurative                1 (2%)                                                                       
   Nose                                               (50)                                                                          
      Inflammation                                     1 (2%)                                                                       
      Goblet Cell, Respiratory Epithelium,                                                                                          
        Hyperplasia                                    1 (2%)                                                                       
      Nasolacrimal Duct, Inflammation                  1 (2%)                                                                       
      Olfactory Epithelium, Degeneration               1 (2%)                                                                       
      Olfactory Epithelium, Inflammation               1 (2%)                                                                       
      Olfactory Epithelium, Glands, Hyperplasia        1 (2%)                                                                       
      Respiratory Epithelium, Cyst                     1 (2%)                                                                       
      Respiratory Epithelium, Inflammation,                                                                                         
        Suppurative                                    1 (2%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (50)                                                                          
      Retinal Detachment                               1 (2%)                                                                       
      Bilateral, Cataract                              1 (2%)                                                                       
      Retina, Atrophy                                  6 (12%)                                                                      
      Retina, Degeneration                             1 (2%)                                                                       
   Harderian Gland                                    (50)                                                                          
      Hemorrhage                                       1 (2%)                                                                       
      Inflammation                                     9 (18%)                                                                      
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                             Page   15                                                              
                                                                                                                                   
NTP Experiment-Test: 96007-03         INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)               Report: PEIRPT03  
Study Type: CHRONIC                             TOXIC EQUIVALENCY FACTOR EVALUATION (TCDD)                        Date: 09/30/03    
Route: GAVAGE                                                                                                     Time: 08:37:05    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         SPRAGUE-DAWLEY RATS FEMALE                100 NG/                                                                          
                                                   KG/STOP                                                                          
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)                                                                          
      Accumulation, Hyaline Droplet                    2 (4%)                                                                       
      Casts Protein                                    1 (2%)                                                                       
      Mineralization                                  42 (84%)                                                                      
      Nephropathy                                     41 (82%)                                                                      
      Papilla, Transitional Epithelium, Hyperplasia    1 (2%)                                                                       
      Pelvis, Dilatation                               1 (2%)                                                                       
      Transitional Epithelium, Hyperplasia             5 (10%)                                                                      
   Urinary Bladder                                    (50)                                                                          
      Inflammation                                     2 (4%)                                                                       
                                                                                                                                    
                                                                                                                                    
a  Number of animals examined microscopically at site and number of animals with lesion                                             
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   16                                                              
                                                                                                                                   
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------