Characterization of benzo[a]pyrene metabolism and related cytochrome P-450 isozymes in Syrian hamster livers.
Cytochrome P-450 monooxygenases of golden Syrian hamsters were characterized with respect to benzo[a]pyrene metabolism. Male hamsters were treated with phenobarbital, 3-methylcholanthrene, dexamethasone, benzoflavone, or ethanol, and the activity of aryl hydrocarbon hydroxylase and benzo[a]pyrene activation was determined by mutagenicity testing in hepatic microsomes. Aryl hydrocarbon hydroxylase activity was induced markedly by treatment with phenobarbital but not with 3-methylcholanthrene, nor with other chemicals. The degree of benzo[a]pyrene activation on mutagenicity testing was significantly elevated by treatment with 3-methylcholanthrene and phenobarbital but was reduced with dexamethasone. Immunoinhibition of these activities and Western blotting of hepatic microsomes using antibodies against cytochrome P-450 isozymes suggested that the isozymes responsible for benzo[a]pyrene metabolism in Syrian hamsters belong to the CYP1A, CYP2A, and CYP3A families, a result that differs from observations in rats.
Sun
B
B
Department of Pharmaceutical Sciences, National Institute of Public Health, Tokyo, Japan.
Fukuhara
M
M
Takanaka
A
A
D000818:Animals; D000906:Antibodies; D001564:Benzo(a)pyrene / Q000378:metabolism*; D015153:Blotting, Western; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D008862:Microsomes, Liver / Q000378:metabolism*; D009152:Mutagenicity Tests
D000906:Antibodies; D007527:Isoenzymes; D001564:Benzo(a)pyrene; D003577:Cytochrome P-450 Enzyme System