Benzo (a) Pyrene Metabolism and Enterohepatic Circulation in the Rat
The polycyclic aromatic hydrocarbon benzo(a)pyrene* is metabolically activated by monooxygenase and epoxide hydrolase (EC. 188.8.131.52) to reactive intermediates, which are mutagenic, cytotoxic and carcinogenic (1–3). The metabolic profile obtained by incubation of BP with various mammalian systems in vitro has been investigated (4). However, the fate of BP in vivo has received relatively little attention. Metabolites of BP are excreted via the bile in the rat (5) and rabbit (6) and BP metabolites in rat bile have recently been shown to be mutagenic to tester strains of Salmonella typhimurium (7). Rat and human intestinal microflora are capable of hydrolyzing conjugates of BP metabolites (8) to release relatively non-polar aglycones.
KeywordsEpoxide Hydrolase ENTEROHEPATIC Circulation Bile Sample Polar Metabolite Glucuronic Acid Conjugate
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