Pyrrolizidine alkaloid-induced alterations in benzo[alpha]pyrene metabolism and binding of benzo[alpha]pyrene metabolites to deoxyribonucleic acid.
Pretreatment of rats by oral administration of jacobine, a pyrrolizidine alkaloid and inducer of epoxide hydrolase, produced a marked shift in hepatic microsomal metabolism in vitro of benzo[alpha]pyrene. The formation of 9-hydroxybenzo[alpha]pyrene and 7,8-dihydroxy-7,8-dihydrobenzo[alpha]pyrene was decreased whereas the formation of 4,5-dihydroxy-4,5-dihydrobenzo[alpha]pyrene was increased following jacobine treatment. This shift in the ratio of benzo[alpha]pyrene metabolites was accompanied by a significant reduction in DNA binding. Addition of purified epoxide hydrolase to control or jacobine microsomes produced a similar decrease in total DNA binding. Chromatography of benzo[alpha]pyrene metabolite-DNA nucleoside adducts showed a marked reduction in four peaks and the elimination of one peak with microsomes from jacobine-treated rats.
D000818:Animals; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D011763:Pyrrolizidine Alkaloids / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D001580:Benzopyrenes; D011763:Pyrrolizidine Alkaloids; D001564:Benzo(a)pyrene; C013581:jacobine; D004247:DNA