Monooxygenase induction by various xenobiotics and its influence on the rat liver microsomal metabolite profile of benz[ a]anthracene

Abstract

Several pesticides (lindane, carbaryl, pentachlorophenol, DDT), polycyclic aromatic hydrocarbons (PAH) and heterocyclic analogues (fluoranthene, dibenz[ a,h]anthracene, dibenz[ a,h]acridine, indeno[1,2,3- cd]pyrene, 10-azabenzo[ a]pyrene) and pharmaceuticals (diphenylhydantoin, ethinylestradiol, levonorgestrel) were tested for their potencies to induce monooxygenase activities in the rat liver by means of recording the metabolite profile of benz[ a]anthracene in rat liver microsomal incubations. Some of them were found to be weak or moderate inducers, but even less efficient ones altered the benz[ a]anthracene metabolite profile significantly. Only indeno [1,2,3- cd]pyrene stimulated the bay-region oxidation of benz[ a]anthracene. A sex-dependent metabolism was observed in both untreated and contraceptive-pretreated Wistar rats.