J. F. Waterfall, P. Sims
Oct 1, 1973
Citations
0
Influential Citations
16
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract Dibenzo[a, h]pyrene and dibenzo[a, i]pyrene are both metabolized to unidentified phenols and dihydrodiols by homogenates and microsomal fractions from the livers of rats that had been pretreated with 3-methylcholanthrene: some properties of these metabolites are described. In comparative experiments, in which the two 3 H-labelled dibenzopyrenes and 3 H-labelled benzo [a]pyrene were metabolized by microsomal fractions from the livers of normal rats, mice, hamsters and guinea-pigs, the dihydrodiols formed initially by the fractions from guinea-pigs, and to a lesser extent those formed by fractions from hamsters were further metabolized to unidentified products. Further metabolism of the dihydrodiols formed by microsomal fractions from the livers of rats and mice did not occur. Higher levels of enzyme-induced binding of all three hydrocarbons to the microsomal proteins were found in the preparations from guinea-pig livers than in the preparations from the livers of animals of the other species and in all preparations maximum levels of binding were reached after 30 min incubation. Enzyme-induced binding of the two dibenzopyrenes to DNA was observed when the 3 H-labelled hydrocarbons and DNA were incubated with microsomal fractions from the livers of rats that had been pretreated with 3-methylcholanthrene, but the levels of binding were low as compared with those obtained with dibenz[a, h]anthracene.