Increased cytochrome P-450 independent drug metabolism and mutagen activation in rat liver by octachlorostyrene.

Single intraperitoneal injections of 200 mg/kg octachlorostyrene (OCS) increased the activities of flavin-containing monooxygenase, epoxide hydrolase and glutathione S-transferase in the livers of male Wistar rats. UDP-glucuronyl transferase activities measured with aglycones increased by methylcholanthrene or phenobarbital treatment, were both slightly increased by OCS treatment. A liver 9,000 X g supernatant fraction from OCS pretreated rats increased the bacterial mutagenicity of 2-acetylaminofluorene and 2-aminofluorene compared to controls, while insignificant or only minor effects were seen on N-hydroxy 2-acetylaminofluorene and benzo(a)pyrene mutagenicity. The effect of OCS on mutagen activation was similar to that seen after phenobarbital treatment. The use of monolayers of hepatocytes instead of 9,000 X g subfractions did not reveal any qualitative differences in mutagen activation.