title: Morphology of nasal-cavity tumours in rats after chronic inhalation of 1,2-dibromo-3-chloropropane.
abstract: Groups of 50 F344 rats of each sex sere exposed to 0.6 or 3.0 pts/10(6) of 1,2-dibromo-3-chloropropane (DBCP) by inhalation for 6 h/day, 5 days/week for 103 weeks. Fifty rats of each sex inhaling filtered air were used as unexposed controls. All survivors were killed at 104 weeks. Up to 93% of the male and female rats developed neoplasms of the nasal cavity. Most of the tumours were adenomas, squamous-cell papillomas, squamous-cell carcinomas, and adenocarcinomas. In the low-dose group 78% of the tumours in males and 66% in females were benign, whereas in the high-dose groups 89% in males and 76% in females were malignant. Invasion through the cribriform plate into the cerebrum or metastasis to the regional lymph nodes was found in 73% of the carcinomas in males and 51% in females. Electron-microscopic examination suggested that the basal cells of the olfactory epithelium were the site of origin of the poorly differentiated adenocarcinomas.
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000281:Administration, Intranasal; D000818:Animals; D000969:Antinematodal Agents / Q000008:administration & dosage / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D003537:Cystadenoma / Q000473:pathology; D005260:Female; D006846:Hydrocarbons, Halogenated / Q000633:toxicity*; D008297:Male; D009296:Nasal Cavity; D009669:Nose Neoplasms / Q000139:chemically induced / Q000473:pathology*; D011407:Propane / Q000031:analogs & derivatives* / Q000633:toxicity; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors
chemical_list: D000969:Antinematodal Agents; D006846:Hydrocarbons, Halogenated; C007318:1,2-dibromo-3-chloropropane; D011407:Propane