Characterization of Cytochrome P450-Monooxygenases of Chinese Hamsters with Respect to Aflatoxin B sub(1) Activation

Chinese and Syrian hamsters and rats were compared for the ability of monooxygenases to activate aflatoxin B sub(1) and induce cytochrome P450 isozymes. Animals were pretreated with phenobarbital or 3-methylcholanthrene prior to sacrifice and preparation of hepatic microsomes for determination of cytochromes P450 and b sub(5), activity of several enzymes, and aflatoxin activation. Chinese hamsters demonstrated greater catalytic activity toward aflatoxin activation than rats with phenobarbital and PCB induction, although the effect was greater with the latter toxicant. This result differed from that found in Syrian hamsters. In Chinese hamsters, phenobarbital pretreatment resulted in slight elevations in the cytochrome P450 isozyme that was immunologically related to CYP2B1, but significantly elevated an isozyme immunologically related to CYP2A2. Significant induction of 7-ethoxycoumarin O-deethylase and testosterone 15- alpha -hydroxylase were also noted in the Chinese hamster.