INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a)
ISOBUTYL NITRITE (IBN)
NTP Experiment-Test: 05185-04 Report: PEIRPT03
Study Type: CHRONIC Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
Facility: I. I. T. Research Institute
Chemical CAS #: 542-56-3
Lock Date: 08/20/92
Cage Range: All
Reasons For Removal: All
Removal Date Range: All
Treatment Groups: Include All
a Number of animals examined microscopically at site and number of animals with lesion
Page 1
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY
Animals Initially In Study 60 60 60 60
Scheduled Sacrifice 9 9 9 10
Early Deaths
Natural Death 16 6 8 10
Moribund Sacrifice 3 3 6 2
Accidently Killed 1
Survivors
Terminal Sacrifice 32 42 36 37
Other 1
Animals Examined Microscopically 60 60 59 60
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM
Gallbladder (55) (55) (54) (51)
Dilatation 1 (2%)
Inflammation, Chronic 1 (2%) 1 (2%)
Intestine Large, Rectum (57) (60) (59) (57)
Dilatation 1 (2%)
Intestine Large, Cecum (57) (58) (59) (55)
Dilatation 1 (2%)
Hyperplasia, Lymphoid 1 (2%)
Intestine Small, Duodenum (51) (59) (58) (52)
Ectopic Tissue 1 (2%)
Proliferation Connective Tissue 1 (2%)
Intestine Small, Jejunum (53) (59) (56) (55)
Hyperplasia, Lymphoid 1 (2%)
Proliferation Connective Tissue 1 (2%)
Serosa, Inflammation, Chronic Active 1 (2%)
Intestine Small, Ileum (53) (57) (59) (54)
Dilatation 1 (2%)
Liver (60) (60) (59) (60)
Angiectasis 1 (2%)
Basophilic Focus 2 (3%) 1 (2%)
Clear Cell Focus 1 (2%) 2 (3%) 1 (2%)
Cytologic Alterations 2 (3%) 1 (2%) 1 (2%)
Eosinophilic Focus 1 (2%) 2 (3%)
Fatty Change, Diffuse 1 (2%)
Fibrosis 1 (2%)
Hematopoietic Cell Proliferation 1 (2%) 1 (2%) 1 (2%)
Hemorrhage 1 (2%)
Hyperplasia 2 (3%)
Infarct 1 (2%) 1 (2%)
Inflammation, Chronic 11 (18%) 7 (12%) 6 (10%) 7 (12%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 2
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT
Inflammation, Chronic Active 2 (3%) 2 (3%) 4 (7%)
Mitotic Alteration 1 (2%)
Mixed Cell Focus 3 (5%) 1 (2%) 1 (2%) 2 (3%)
Necrosis 1 (2%) 2 (3%) 2 (3%) 1 (2%)
Pigmentation 1 (2%)
Proliferation Connective Tissue 1 (2%)
Fat, Necrosis 1 (2%)
Hepatocyte, Necrosis 1 (2%) 1 (2%) 1 (2%)
Periportal, Fatty Change 1 (2%) 1 (2%)
Periportal, Hypertrophy 1 (2%)
Mesentery (7) (4) (3) (2)
Cyst 1 (25%)
Proliferation Connective Tissue 1 (25%)
Artery, Inflammation, Chronic 1 (14%)
Fat, Necrosis 5 (71%) 4 (100%) 2 (67%) 2 (100%)
Pancreas (60) (60) (59) (60)
Fibrosis 1 (2%)
Inflammation, Chronic 4 (7%) 3 (5%)
Inflammation, Chronic Active 1 (2%)
Acinus, Atrophy 1 (2%) 2 (3%) 3 (5%) 2 (3%)
Duct, Dilatation 1 (2%) 1 (2%)
Salivary Glands (60) (60) (59) (60)
Atrophy 1 (2%)
Hemorrhage 1 (2%)
Inflammation, Chronic 49 (82%) 44 (73%) 33 (56%) 32 (53%)
Inflammation, Chronic Active 1 (2%)
Stomach, Forestomach (60) (60) (59) (59)
Angiectasis 1 (2%)
Developmental Malformation 1 (2%)
Proliferation Connective Tissue 1 (2%)
Ulcer 1 (2%)
Stomach, Glandular (60) (60) (59) (59)
Proliferation Connective Tissue 1 (2%)
____________________________________________________________________________________________________________________________________
CARDIOVASCULAR SYSTEM
Heart (60) (60) (59) (60)
Infiltration Cellular 1 (2%)
Inflammation, Chronic 1 (2%)
Thrombosis 1 (2%) 1 (2%)
Artery, Hypertrophy 1 (2%)
Artery, Inflammation, Chronic 1 (2%) 1 (2%) 1 (2%)
____________________________________________________________________________________________________________________________________
a Number of animals examined microscopically at site and number of animals with lesion
Page 3
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
ENDOCRINE SYSTEM
Adrenal Cortex (59) (60) (59) (59)
Cyst 3 (5%)
Hyperplasia, Focal 2 (3%)
Hypertrophy, Focal 1 (2%) 2 (3%)
Subcapsular, Hyperplasia 56 (95%) 56 (93%) 54 (92%) 53 (90%)
Adrenal Medulla (55) (58) (54) (57)
Hyperplasia, Focal 2 (3%) 1 (2%)
Islets, Pancreatic (2) (2) (3) (3)
Hyperplasia, Focal 2 (100%) 1 (50%) 3 (100%) 2 (67%)
Pituitary Gland (56) (56) (59) (57)
Cyst 1 (2%)
Pars Distalis, Angiectasis 1 (2%) 1 (2%) 2 (4%)
Pars Distalis, Cyst 1 (2%) 1 (2%) 1 (2%) 2 (4%)
Pars Distalis, Hemorrhage 1 (2%)
Pars Distalis, Hyperplasia 10 (18%) 12 (21%) 12 (20%) 7 (12%)
Pars Distalis, Hyperplasia, Focal 1 (2%)
Thyroid Gland (60) (60) (59) (60)
Ectopic Thymus 1 (2%)
Infiltration Cellular, Lymphocyte 1 (2%)
Inflammation, Chronic 3 (5%)
Follicle, Cyst 1 (2%) 5 (8%) 4 (7%)
Follicular Cell, Hyperplasia, Diffuse 1 (2%) 1 (2%)
Follicular Cell, Hyperplasia, Focal 5 (8%) 9 (15%) 7 (12%) 5 (8%)
____________________________________________________________________________________________________________________________________
GENERAL BODY SYSTEM
None
____________________________________________________________________________________________________________________________________
GENITAL SYSTEM
Clitoral Gland (1) (2) (5)
Dilatation 1 (100%) 1 (50%) 1 (20%)
Pigmentation 3 (60%)
Ovary (58) (59) (55) (59)
Angiectasis 1 (2%)
Cyst 10 (17%) 15 (25%) 10 (18%) 13 (22%)
Hemorrhage 1 (2%)
Infiltration Cellular, Lymphocyte 1 (2%) 1 (2%)
Interstitium, Hyperplasia 1 (2%)
Uterus (60) (60) (58) (59)
Angiectasis 2 (3%) 1 (2%)
Developmental Malformation 1 (2%)
Dilatation 1 (2%)
Hemorrhage 1 (2%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 4
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
GENITAL SYSTEM - CONT
Hyperplasia 1 (2%)
Hyperplasia, Cystic 49 (82%) 51 (85%) 50 (86%) 54 (92%)
Inflammation, Chronic Active 1 (2%)
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM
Bone Marrow (60) (60) (59) (60)
Atrophy 1 (2%)
Degeneration, Fatty 1 (2%)
Myeloid Cell, Hyperplasia 1 (2%) 3 (5%)
Lymph Node (4) (5) (8) (6)
Hyperplasia, Lymphoid 1 (20%)
Pigmentation 1 (20%)
Iliac, Hemorrhage 1 (13%)
Iliac, Hyperplasia, Lymphoid 1 (20%)
Iliac, Inflammation, Chronic Active 1 (13%)
Iliac, Pigmentation 1 (17%)
Inguinal, Pigmentation 1 (17%)
Lumbar, Angiectasis 1 (13%)
Lumbar, Hemorrhage 1 (13%)
Lumbar, Hyperplasia, Lymphoid 1 (17%)
Pancreatic, Hyperplasia, Lymphoid 1 (20%)
Renal, Hemorrhage 1 (13%)
Lymph Node, Bronchial (28) (42) (40) (38)
Hemorrhage 1 (2%) 1 (3%)
Hyperplasia, Lymphoid 1 (4%) 4 (10%)
Lymph Node, Mandibular (58) (57) (57) (55)
Hemorrhage 1 (2%) 2 (4%) 1 (2%)
Hyperplasia, Lymphoid 2 (3%) 1 (2%) 2 (4%) 1 (2%)
Inflammation, Chronic Active 1 (2%)
Lymph Node, Mesenteric (60) (59) (58) (55)
Angiectasis 1 (2%)
Hematopoietic Cell Proliferation 1 (2%)
Hemorrhage 1 (2%) 1 (2%)
Hyperplasia, Lymphoid 1 (2%) 1 (2%) 1 (2%)
Hyperplasia, Plasma Cell 1 (2%)
Inflammation, Chronic Active 1 (2%)
Lymph Node, Mediastinal (58) (51) (52) (53)
Hyperplasia, Lymphoid 6 (10%) 4 (8%) 3 (6%) 3 (6%)
Inflammation, Chronic Active 1 (2%)
Spleen (60) (60) (59) (59)
Angiectasis 1 (2%)
Atrophy 1 (2%)
Fibrosis 1 (2%)
Hematopoietic Cell Proliferation 54 (90%) 49 (82%) 54 (92%) 54 (92%)
Hyperplasia, Lymphoid 6 (10%) 7 (12%) 6 (10%) 3 (5%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 5
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM - CONT
Pigmentation, Hemosiderin 54 (90%) 52 (87%) 46 (78%) 57 (97%)
Proliferation Connective Tissue 1 (2%)
Thymus (56) (56) (57) (51)
Atrophy 11 (20%) 2 (4%) 5 (9%) 6 (12%)
Ectopic Parathyroid Gland 1 (2%)
Hemorrhage 1 (2%)
Hyperplasia, Lymphoid 5 (9%) 10 (18%) 6 (11%) 2 (4%)
____________________________________________________________________________________________________________________________________
INTEGUMENTARY SYSTEM
Mammary Gland (58) (60) (59) (60)
Dilatation 1 (2%) 2 (3%)
Hyperplasia 2 (3%) 1 (2%) 1 (2%) 2 (3%)
Skin (60) (60) (59) (60)
Inflammation, Chronic 6 (10%) 4 (7%)
Inflammation, Chronic Active 4 (7%) 2 (3%)
Ulcer 1 (2%)
Epithelium, Hyperplasia 1 (2%) 2 (3%) 2 (3%)
Sebaceous Gland, Hyperplasia, Focal 1 (2%)
____________________________________________________________________________________________________________________________________
MUSCULOSKELETAL SYSTEM
Bone (60) (60) (59) (60)
Developmental Malformation 1 (2%)
Dysplasia 24 (40%) 18 (30%) 25 (42%) 28 (47%)
Hyperostosis 1 (2%)
Maxilla, Fracture 1 (2%)
Skeletal Muscle (3) (1) (1)
Hemorrhage 1 (100%)
Proliferation Connective Tissue 1 (33%)
____________________________________________________________________________________________________________________________________
NERVOUS SYSTEM
Brain (59) (60) (59) (60)
Compression 1 (2%) 1 (2%) 4 (7%) 2 (3%)
Hemorrhage 2 (3%) 1 (2%)
Mineralization 45 (76%) 26 (43%) 31 (53%) 27 (45%)
Meninges, Inflammation, Chronic Active 1 (2%)
Spinal Cord (1)
Inflammation, Chronic 1 (100%)
____________________________________________________________________________________________________________________________________
a Number of animals examined microscopically at site and number of animals with lesion
Page 6
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
RESPIRATORY SYSTEM
Larynx (60) (58) (59) (59)
Artery, Inflammation, Chronic 1 (2%)
Lung (60) (60) (59) (60)
Infiltration Cellular, Lymphocyte 28 (47%) 14 (23%) 11 (19%) 23 (38%)
Inflammation, Chronic Active 3 (5%) 3 (5%) 1 (2%)
Leukocytosis 1 (2%)
Alveolar Epithelium, Hyperplasia, Focal 2 (3%) 10 (17%) 8 (13%)
Alveolus, Infiltration Cellular, Histiocyte 1 (2%) 1 (2%) 2 (3%)
Artery, Inflammation, Chronic 1 (2%)
Fat, Mediastinum, Necrosis 1 (2%)
Nose (60) (60) (59) (60)
Exudate 1 (2%)
Exudate, Serous 1 (2%) 1 (2%) 2 (3%) 23 (38%)
Inflammation, Chronic Active 6 (10%) 10 (17%) 12 (20%) 12 (20%)
Olfactory Epithelium, Atrophy 1 (2%) 16 (27%)
Olfactory Epithelium, Degeneration, Hyaline 4 (7%) 3 (5%) 5 (8%) 3 (5%)
Olfactory Epithelium, Metaplasia 6 (10%) 2 (3%) 2 (3%)
Olfactory Epithelium, Metaplasia, Squamous 1 (2%) 1 (2%)
Respiratory Epithelium, Degeneration, Hyaline 19 (32%) 26 (43%) 14 (24%) 19 (32%)
Respiratory Epithelium, Hyperplasia 6 (10%) 3 (5%) 4 (7%) 1 (2%)
Respiratory Epithelium, Metaplasia, Squamous 4 (7%) 5 (8%) 6 (10%)
Respiratory Epithelium, Ulcer 3 (5%) 4 (7%) 3 (5%) 3 (5%)
____________________________________________________________________________________________________________________________________
SPECIAL SENSES SYSTEM
Eye (1)
Phthisis Bulbi 1 (100%)
____________________________________________________________________________________________________________________________________
URINARY SYSTEM
Kidney (60) (60) (59) (60)
Amyloid Deposition 1 (2%)
Cyst 1 (2%)
Glomerulosclerosis 1 (2%)
Hydronephrosis 1 (2%) 1 (2%)
Infarct 1 (2%)
Infiltration Cellular, Lymphocyte 35 (58%) 19 (32%) 19 (32%) 31 (52%)
Nephropathy 2 (3%) 1 (2%)
Renal Tubule, Degeneration, Hyaline 1 (2%)
Renal Tubule, Dilatation 2 (3%) 1 (2%) 2 (3%) 1 (2%)
Renal Tubule, Hyperplasia, Focal 1 (2%) 1 (2%)
Renal Tubule, Pigmentation 1 (2%)
Renal Tubule, Regeneration 1 (2%) 1 (2%)
Urinary Bladder (58) (59) (57) (57)
a Number of animals examined microscopically at site and number of animals with lesion
Page 7
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE FEMALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
URINARY SYSTEM - CONT
Dilatation 1 (2%)
Infiltration Cellular, Lymphocyte 38 (66%) 40 (68%) 24 (42%) 34 (60%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 8
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
DISPOSITION SUMMARY
Animals Initially In Study 60 60 60 60
Scheduled Sacrifice 10 10 10 7
Early Deaths
Natural Death 10 8 11 17
Accidently Killed 2 2
Moribund Sacrifice 1 7 4 4
Survivors
Terminal Sacrifice 37 35 35 30
Animals Examined Microscopically 60 60 60 60
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM
Gallbladder (51) (50) (51) (53)
Inflammation, Chronic Active 1 (2%)
Intestine Large, Cecum (54) (55) (55) (50)
Hyperplasia, Lymphoid 2 (4%)
Intestine Small, Duodenum (53) (55) (55) (50)
Proliferation Connective Tissue 1 (2%)
Intestine Small, Jejunum (52) (55) (56) (50)
Hyperplasia, Lymphoid 1 (2%)
Inflammation, Chronic Active 1 (2%)
Liver (60) (60) (60) (60)
Abscess 1 (2%)
Angiectasis 1 (2%) 1 (2%)
Basophilic Focus 3 (5%) 2 (3%) 2 (3%) 2 (3%)
Clear Cell Focus 2 (3%) 3 (5%) 3 (5%)
Cytologic Alterations 3 (5%) 2 (3%) 2 (3%)
Developmental Malformation 1 (2%)
Eosinophilic Focus 1 (2%) 1 (2%)
Fatty Change, Focal 1 (2%) 1 (2%)
Hematopoietic Cell Proliferation 1 (2%) 1 (2%) 1 (2%)
Hyperplasia 1 (2%)
Infarct 2 (3%) 2 (3%) 3 (5%) 2 (3%)
Inflammation, Chronic 1 (2%) 5 (8%)
Inflammation, Chronic Active 1 (2%) 1 (2%)
Mixed Cell Focus 5 (8%) 1 (2%) 1 (2%)
Necrosis 1 (2%) 3 (5%) 3 (5%) 4 (7%)
Proliferation Connective Tissue 1 (2%) 1 (2%)
Syncytial Alteration 12 (20%) 14 (23%) 16 (27%) 11 (18%)
Vacuolization Cytoplasmic 1 (2%)
Bile Duct, Cyst 2 (3%)
Bile Duct, Hyperplasia 1 (2%) 1 (2%)
Centrilobular, Fatty Change 5 (8%) 6 (10%) 4 (7%) 1 (2%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 9
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
ALIMENTARY SYSTEM - CONT
Centrilobular, Necrosis 2 (3%)
Hepatocyte, Necrosis 1 (2%)
Midzonal, Fatty Change 1 (2%)
Periportal, Vacuolization Cytoplasmic 1 (2%)
Mesentery (1) (5) (2)
Artery, Inflammation, Chronic Active 1 (20%)
Fat, Necrosis 1 (100%) 2 (40%) 2 (100%)
Pancreas (60) (59) (60) (56)
Inflammation, Chronic 3 (5%) 3 (5%)
Inflammation, Chronic Active 1 (2%)
Proliferation Connective Tissue 1 (2%)
Acinus, Atrophy 1 (2%) 1 (2%) 1 (2%) 1 (2%)
Duct, Cyst 1 (2%)
Salivary Glands (60) (60) (60) (60)
Inflammation, Chronic 36 (60%) 33 (55%) 29 (48%) 29 (48%)
Stomach, Glandular (59) (59) (59) (56)
Dysplasia 1 (2%)
Necrosis 1 (2%) 1 (2%) 2 (4%)
Ulcer 1 (2%)
Tooth (3) (1) (1)
Dysplasia 1 (33%)
____________________________________________________________________________________________________________________________________
CARDIOVASCULAR SYSTEM
Heart (60) (60) (60) (60)
Cardiomyopathy 1 (2%)
Degeneration 1 (2%)
Mineralization 1 (2%)
Thrombosis 1 (2%)
Artery, Inflammation, Chronic Active 1 (2%) 1 (2%)
____________________________________________________________________________________________________________________________________
ENDOCRINE SYSTEM
Adrenal Cortex (59) (59) (58) (58)
Cyst 3 (5%) 1 (2%)
Hyperplasia 1 (2%)
Hypertrophy, Focal 6 (10%) 16 (27%) 10 (17%) 9 (16%)
Capsule, Accessory Adrenal Cortical Nodule 2 (3%) 1 (2%)
Subcapsular, Hyperplasia 33 (56%) 26 (44%) 18 (31%) 24 (41%)
Adrenal Medulla (59) (59) (58) (58)
Hyperplasia, Focal 2 (3%)
Islets, Pancreatic (5) (3) (9) (1)
Hyperplasia, Focal 3 (60%) 3 (100%) 7 (78%) 1 (100%)
Pituitary Gland (56) (56) (54) (54)
Pars Distalis, Cyst 1 (2%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 10
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
ENDOCRINE SYSTEM - CONT
Pars Distalis, Hyperplasia 1 (2%) 1 (2%)
Pars Distalis, Hyperplasia, Focal 1 (2%) 1 (2%)
Thyroid Gland (60) (60) (60) (60)
Ultimobranchial Cyst 1 (2%)
Follicular Cell, Hyperplasia 1 (2%)
Follicular Cell, Hyperplasia, Focal 8 (13%) 17 (28%) 12 (20%) 20 (33%)
____________________________________________________________________________________________________________________________________
GENERAL BODY SYSTEM
None
____________________________________________________________________________________________________________________________________
GENITAL SYSTEM
Epididymis (60) (60) (60) (60)
Inflammation, Chronic Active 1 (2%) 2 (3%) 3 (5%) 8 (13%)
Spermatocele 1 (2%)
Penis (1) (1) (1) (5)
Congestion 1 (20%)
Inflammation, Chronic Active 1 (100%) 1 (100%) 3 (60%)
Preputial Gland (19) (22) (18) (14)
Abscess 3 (14%) 2 (11%) 1 (7%)
Dilatation 16 (84%) 14 (64%) 17 (94%) 11 (79%)
Inflammation, Chronic Active 6 (32%) 6 (27%) 5 (28%) 4 (29%)
Prostate (60) (59) (59) (60)
Hyperplasia, Focal 1 (2%)
Inflammation, Acute 1 (2%) 2 (3%)
Inflammation, Chronic Active 1 (2%) 1 (2%) 4 (7%) 3 (5%)
Seminal Vesicle (60) (60) (60) (60)
Dilatation 4 (7%) 7 (12%) 12 (20%) 3 (5%)
Hyperplasia 1 (2%)
Inflammation, Acute 1 (2%)
Inflammation, Chronic Active 1 (2%) 1 (2%)
Testes (60) (60) (60) (60)
Mineralization 1 (2%)
Spermatocele 1 (2%)
Seminiferous Tubule, Degeneration 2 (3%) 1 (2%)
Tunic, Inflammation, Chronic 1 (2%)
Tunic, Proliferation Connective Tissue 1 (2%)
____________________________________________________________________________________________________________________________________
a Number of animals examined microscopically at site and number of animals with lesion
Page 11
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
HEMATOPOIETIC SYSTEM
Bone Marrow (60) (60) (59) (59)
Infarct 1 (2%)
Myeloid Cell, Hyperplasia 3 (5%) 5 (8%) 7 (12%) 9 (15%)
Lymph Node (1) (5) (5) (5)
Iliac, Infiltration Cellular, Histiocyte 1 (20%)
Iliac, Inflammation, Chronic Active 1 (20%)
Inguinal, Hyperplasia, Lymphoid 2 (40%)
Inguinal, Inflammation, Chronic Active 1 (20%)
Inguinal, Pigmentation 1 (20%)
Lumbar, Hemorrhage 1 (20%)
Lumbar, Hyperplasia, Histiocytic 1 (20%)
Lumbar, Hyperplasia, Lymphoid 1 (20%) 1 (20%)
Lumbar, Hyperplasia, Plasma Cell 1 (20%)
Renal, Hyperplasia, Plasma Cell 1 (20%) 1 (20%)
Lymph Node, Bronchial (33) (45) (26) (39)
Hemorrhage 1 (2%)
Hyperplasia, Lymphoid 1 (2%) 1 (4%) 1 (3%)
Infiltration Cellular, Histiocyte 1 (3%)
Inflammation, Chronic Active 1 (4%)
Lymph Node, Mandibular (49) (59) (60) (55)
Hemorrhage 1 (2%)
Hyperplasia, Lymphoid 1 (2%) 1 (2%) 1 (2%)
Pigmentation, Hemosiderin 1 (2%)
Lymph Node, Mesenteric (57) (57) (57) (56)
Angiectasis 1 (2%)
Hematopoietic Cell Proliferation 1 (2%) 1 (2%)
Hemorrhage 2 (4%) 4 (7%) 5 (9%) 6 (11%)
Hyperplasia, Lymphoid 3 (5%) 1 (2%) 1 (2%)
Hyperplasia, Plasma Cell 2 (4%)
Lymph Node, Mediastinal (48) (47) (48) (46)
Hemorrhage 1 (2%) 1 (2%) 1 (2%)
Hyperplasia, Lymphoid 2 (4%)
Hyperplasia, Plasma Cell 1 (2%)
Spleen (60) (60) (59) (58)
Fibrosis 1 (2%)
Hematopoietic Cell Proliferation 59 (98%) 53 (88%) 57 (97%) 55 (95%)
Hematopoietic Cell Proliferation Granulocytic 1 (2%) 2 (3%)
Hyperplasia, Lymphoid 2 (3%)
Pigmentation, Hemosiderin 34 (57%) 26 (43%) 55 (93%) 56 (97%)
Lymphoid Follicle, Atrophy 2 (3%)
Thymus (55) (56) (48) (50)
Atrophy 13 (24%) 12 (21%) 7 (15%) 9 (18%)
Cyst 1 (2%)
Ectopic Parathyroid Gland 1 (2%)
Hyperplasia, Lymphoid 1 (2%) 1 (2%)
____________________________________________________________________________________________________________________________________
a Number of animals examined microscopically at site and number of animals with lesion
Page 12
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
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B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
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INTEGUMENTARY SYSTEM
Skin (60) (60) (59) (59)
Inflammation, Chronic 1 (2%) 2 (3%)
Inflammation, Chronic Active 3 (5%) 2 (3%) 3 (5%)
Ulcer 2 (3%) 2 (3%)
Epithelium, Hyperplasia 1 (2%) 1 (2%)
Fat, Necrosis 1 (2%)
Hair Follicle, Atrophy 1 (2%)
Prepuce, Inflammation, Chronic Active 1 (2%) 1 (2%) 1 (2%)
Prepuce, Ulcer 1 (2%)
Subcutaneous Tissue, Edema 1 (2%)
Subcutaneous Tissue, Granuloma 1 (2%)
Subcutaneous Tissue, Hemorrhage 1 (2%)
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MUSCULOSKELETAL SYSTEM
Bone (60) (60) (60) (60)
Developmental Malformation 1 (2%)
Dysplasia 1 (2%)
Fracture 1 (2%)
Hyperostosis 1 (2%)
Cartilage, Degeneration 1 (2%)
Maxilla, Callus 1 (2%)
Maxilla, Fracture 2 (3%)
Skeletal Muscle (1) (1)
Inflammation, Chronic Active 1 (100%)
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NERVOUS SYSTEM
Brain (60) (60) (60) (60)
Mineralization 41 (68%) 36 (60%) 31 (52%) 24 (40%)
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RESPIRATORY SYSTEM
Larynx (60) (60) (59) (57)
Inflammation, Acute 1 (2%)
Inflammation, Chronic Active 1 (2%)
Lung (60) (60) (59) (60)
Congestion 1 (2%)
Infiltration Cellular, Lymphocyte 1 (2%) 3 (5%) 2 (3%) 3 (5%)
Inflammation, Chronic Active 3 (5%)
Leukocytosis 1 (2%)
Alveolar Epithelium, Hyperplasia, Focal 1 (2%) 4 (7%) 7 (12%) 13 (22%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 13
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
RESPIRATORY SYSTEM - CONT
Alveolus, Infiltration Cellular, Histiocyte 1 (2%) 2 (3%) 2 (3%)
Nose (60) (60) (60) (60)
Exudate 1 (2%)
Exudate, Serous 2 (3%)
Inflammation, Chronic Active 8 (13%) 8 (13%) 7 (12%) 10 (17%)
Olfactory Epithelium, Atrophy 1 (2%) 1 (2%)
Olfactory Epithelium, Degeneration, Hyaline 4 (7%) 2 (3%) 2 (3%)
Olfactory Epithelium, Metaplasia 3 (5%) 1 (2%) 3 (5%) 1 (2%)
Respiratory Epithelium, Degeneration, Hyaline 4 (7%) 3 (5%) 3 (5%) 3 (5%)
Respiratory Epithelium, Hyperplasia 13 (22%) 20 (33%) 19 (32%) 8 (13%)
Respiratory Epithelium, Metaplasia, Squamous 3 (5%) 3 (5%)
Respiratory Epithelium, Ulcer 2 (3%) 1 (2%)
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SPECIAL SENSES SYSTEM
Eye (1) (2)
Phthisis Bulbi 1 (100%) 1 (50%)
Cornea, Inflammation, Chronic Active 1 (50%)
Lens, Cataract 1 (50%)
Harderian Gland (5) (1) (3) (6)
Inflammation, Chronic Active 1 (100%)
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URINARY SYSTEM
Kidney (60) (60) (60) (60)
Abscess 1 (2%)
Amyloid Deposition 1 (2%)
Cyst 2 (3%) 1 (2%) 2 (3%) 2 (3%)
Hydronephrosis 2 (3%) 2 (3%) 5 (8%)
Infarct 2 (3%) 1 (2%)
Infiltration Cellular, Lymphocyte 17 (28%) 18 (30%) 13 (22%) 23 (38%)
Inflammation, Acute 1 (2%) 2 (3%)
Inflammation, Chronic Active 1 (2%) 3 (5%) 5 (8%) 6 (10%)
Metaplasia, Osseous 1 (2%) 1 (2%)
Mineralization 1 (2%)
Nephropathy 1 (2%) 1 (2%)
Artery, Inflammation, Chronic Active 1 (2%)
Renal Tubule, Dilatation 1 (2%) 3 (5%) 6 (10%)
Renal Tubule, Hyperplasia, Focal 1 (2%) 2 (3%) 2 (3%)
Renal Tubule, Regeneration 12 (20%) 6 (10%) 5 (8%) 4 (7%)
Urinary Bladder (60) (58) (59) (57)
Dilatation 7 (12%) 7 (12%) 14 (24%) 9 (16%)
Infiltration Cellular, Lymphocyte 2 (3%) 4 (7%) 1 (2%) 5 (9%)
Inflammation, Acute 1 (2%) 1 (2%)
Inflammation, Chronic Active 2 (3%) 3 (5%) 5 (8%) 8 (14%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 14
NTP Experiment-Test: 05185-04 INCIDENCE RATES OF NONNEOPLASTIC LESIONS BY ANATOMIC SITE (a) Report: PEIRPT03
Study Type: CHRONIC ISOBUTYL NITRITE (IBN) Date: 05/20/95
Route: RESPIRATORY EXPOSURE WHOLE BODY Time: 11:28:48
____________________________________________________________________________________________________________________________________
B6C3F1 MICE MALE CONTROL 37.5 PPM 75 PPM 150 PPM
____________________________________________________________________________________________________________________________________
URINARY SYSTEM - CONT
Transitional Epithelium, Hyperplasia 1 (2%) 1 (2%)
a Number of animals examined microscopically at site and number of animals with lesion
Page 15
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