Effect of enzyme induction on the metabolism and tissue distribution of benzo(alpha)pyrene.

Abstract

Pretreatment of rats with benzo(α)pyrene, 3-methylcholanthrene, or 7,12-dimethylbenz(α)anthracene p.o. once daily for two days prior to the i.v. administration of tritiated benzo(α)-pyrene (BP-3H) on the third day stimulates the disappearance of BP-3H from blood and decreases the concentration of BP-3H in various tissues. Pretreatment of rats with pyrene, anthracene, or phenobarbital does not stimulate the in vivo disappearance of BP-3H. The concentration of BP-3H in the fat of rats is lower after seven daily p.o. doses of BP-3H than after a single dose of BP-3H, which suggests that this hydrocarbon stimulates its own metabolism during chronic administration.