Time course of metabolism of benzo[e]pyrene by hamster embryo cells and the effect of chemical modifiers

In cultures of hamster embryo cells, benzoa]pyrene (Ba]P) is metabolized primarily in the bay region. In contrast, little or no bay region metabolism of the noncarcinogenic isomer benzoe]pyrene (Be]P) could be detected during 12–96-h incubations of hamster embryo cells with 4 μM ³H]Be]P. The upper limit to 9,10-dihydro-9,10-dihydroxy-Be]P formation is about 0.2% of the ethyl acetate-soluble metabolites ( <0.1% of the total metabolites). The major identified metabolites of Be]P were 4,5-dihydro-4,5-dihydroxy Be]P and the glucuronide conjugates of 3-OH-Be]P and 4,5-dihydro-4,5-dihydroxy Be]P. Simultaneous treatment of cells with either Ba]P or 7,8-benzoflavone (BF) did not induce bay region metabolism of ³H]Be]P.