National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/9476

Target Organs and Levels of Evidence for TR-370

Toxicology and Carcinogenesis Studies of Benzofuran (CASRN 271-89-6) in F344/N Rats and B6C3F1 Mice (Gavage Studies)

Chemical (Study Title)
CASRN
Peer Review DatePrimary UsesRoute/Exposure LevelsStudy Laboratory
Benzofuran
271-89-6
03/13/1989Manufacture of coumarone-indene resins. Associated with tobacco: reported either as a natural component of tobacco, pyrolysis product (in tobacco smoke), or additive for one or more types of tobacco products.Gavage
FR&MM: 0,60,120, MR: 0,30,60, FM: 0,120,240 MG/KG/50 PER GROUP
Springborn Inst. for Bioresearch, Inc.

Levels of Evidence

Male Rats: No Evidence
TypeOrgan/Tissue (Lesion)
Non-Neoplastic Lesions
  • KIDNEY: INCREASED SEVERITY OF NEPHROPATHY
Female Rats: Some Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Kidney Tubular Cell: ADENOCARCINOMA 0/50 1/50 4/50
Non-Neoplastic Lesions
  • KIDNEY: NEPHROPATHY 29/50 48/50 39/50
  • PANCREAS: METAPLASIA 0/50 1/50 11/49
Male Mice: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: ADENOMA 4/49 24/39 34/48; HEPATOBLASTOMA 0/49 3/39 18/48; ADENOMA, HEPATOBLASTOMA, OR CARCINOMA 9/49 8/39 9/48 COMBINED 12/49 31/39 40/48
  • Forestomach: SQUAMOUS CELL PAPILLOMA 2/49 7/39 10/48 OR SQUAMOUS CELL CARCINOMA 0/49 4/39 3/48 COMBINED 2/49 11/39 13/48
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 4/49 7/39 15/48 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 7/49 3/39 5/48 COMBINED 10/49 9/39 19/48
Non-Neoplastic Lesions
  • LIVER: SYNCYTIAL ALTERATION 4/49 18/39 36/48
  • LUNG: BRONCHIAL EPITHELIAL HYPERPLASIA 3/49 11/39 14/48
  • FORESTOMACH: EPITHELIAL HYPERPLASIA 16/49 13/39 24/48
Female Mice: Clear Evidence
TypeOrgan/Tissue (Lesion)
Neoplastic Lesions
  • Liver: ADENOMA 1/50 22/48 21/47; HEPATOBLASTOMA 0/50 1/48 2/47; ADENOMA, HEPATOBLASTOMA, OR CARCINOMA 3/50 3/48 1/47 COMBINED 4/50 25/48 22/47
  • Lung: ALVEOLAR/BRONCHIOLAR ADENOMA 1/50 5/48 13/47 OR ALVEOLAR/BRONCHIOLAR CARCINOMA 1/50 4/48 3/47 COMBINED 2/50 9/48 14/47
  • Forestomach: SQUAMOUS CELL PAPILLOMA 2/50 8/50 5/50 OR SQUAMOUS CELL CARCINOMA 0/50 1/50 1/50 COMBINED 2/50 9/50 5/50
Non-Neoplastic Lesions
  • LIVER: SYNCYTIAL ALTERATION 1/50 0/48 2/47
  • LUNG: BRONCHIAL EPITHELIAL HYPERPLASIA 1/50 22/48 34/47
  • FORESTOMACH: EPITHELIAL HYPERPLASIA 7/50 19/48 13/47


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