Studies with chlorinated dibenzo-p-dioxins, polybrominated biphenyls, and polychlorinated biphenyls in a two-stage system of mouse skin tumorigenesis: potent anticarcinogenic effects
- Oak Ridge National Lab., TN
The chlorinated dibenzo-p-dioxins and chlorinated dibenzo-furans are among the most potent teratogens and toxins that are found as environmental contaminants. The polychlorinated biphenyls and polybrominated biphenyls are not nearly as toxic as the dioxins, but they are environmentally more prevalent than the dioxins. Both classes of compounds are inducers of cytochrome P/sub 450/-mediated microsomal monooxygenases and of aminolevulinic acid synthetase. The dioxins induce aryl hydrocarbon hydroxylase, the enzyme system responsible for converting polycyclic aromatic hydrocarbons to active and inactive metabolites. PCB's and PBB's induce the monooxygenase system with properties similar to both phenobarbital and 3-MC. Timing is important in the application of PCB to the diets of laboratory animals. Treatment with PCB's prior to the administration of carcinogen results in reduction of tumor response whereas treatment subsequent to application of the carcinogen results in enhancement of the tumorogenic response. The two-stage system of mouse skin tumorigenesis allows one to evaluate critically the initiation and promotion phases of carcinogenesis individually. (DLS)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6388626
- Journal Information:
- Ann. N.Y. Acad. Sci.; (United States), Vol. 320
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BIPHENYL
CARCINOGENESIS
TOXICITY
DIOXIN
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
AROMATICS
BIOCHEMISTRY
ENZYME ACTIVITY
ENZYMES
MICE
NEOPLASMS
SKIN
TOXINS
TUMOR PROMOTERS
ANIMALS
ANTIGENS
BODY
CHEMISTRY
DISEASES
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
MAMMALS
MATERIALS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PATHOGENESIS
PROMOTERS
RODENTS
TOXIC MATERIALS
VERTEBRATES
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)