Induction of preneoplastic and neoplastic lesions in grafted rat tracheas continuously exposed to benzo(a)pyrene
Heterotopically transplanted rat tracheas were continuously exposed to measured amounts of benzo(a)pyrene over a period of 1 to 6 months. The cumulative doses ranged from 10 to 2490 ..mu..g. The morphological response of the tracheal epithelium was characterized by hyperplasia during the first 2 weeks, followed by atrophy. Squamous metaplasias did not appear until after 4 months of exposure; at 4 and 6 months numerous dysplastic lesions and noninvasive carcinomas resembling those seen in the airways of humans were found in the higher carcinogen dose groups. The first invasive carcinomas developed at 4 months in the groups given 1250 ..mu..g or more benzo(a)pyrene. The lowest dose tested that produced a carcinoma within the observation period of 22 months was 300 ..mu..g benzo(a)pyrene. The majority of the neoplasms were squamous cell carcinomas, although several adenocarcinomas and sarcomas also developed. Since a variety of metaplastic and dysplastic lesions can be induced by carcinogenic polycyclic hydrocarbons in the transplanted rat tracheas, this experimental model appears to be well suited for the study of the sequential epithelial changes that lead to respiratory tract neoplasia.
- Research Organization:
- Oak Ridge National Lab., TN
- OSTI ID:
- 7297945
- Journal Information:
- Cancer Res.; (United States), Journal Name: Cancer Res.; (United States) Vol. 37; ISSN CNREA
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AROMATICS
BENZOPYRENE
BIOLOGICAL EFFECTS
BODY
CARCINOGENS
CONDENSED AROMATICS
DISEASES
EPITHELIUM
HYDROCARBONS
MAMMALS
NEOPLASMS
ORGANIC COMPOUNDS
RATS
RESPIRATORY SYSTEM
RODENTS
TISSUES
TRACHEA
TRANSPLANTS
VERTEBRATES