Studies on the hepatic microsomal metabolism of [14C]phenanthrene

[¹⁴C]Phenanthrene was metabolished in vitro by hepatic microsomes obtained from untreated, sodium phenobarbital (PB), and 3-methylcholanthrene (MC) pretreated Wistar rats, guinea pigs, SW and DBA/2J mouse strains. Metabolite profiles were obtained by comparison of thinlayer radiochromatographs of the products with R_fs of authentic reference compounds, trans-dihydrodi-hydroxyphenanthrenes (dihydrodiols) were the major metabolites in all preparations. In every case, except with microsomes from MC pretreated guinea pigs, trans — 9,10 — dihydro — 9,10 — dihydroxyphenanthrene predominated. With microsomes from MC pretreated guinea pigs, the 1,2-dihydrodiol was the major metabolite. Addition of cyclohexene oxide (5.0 mM) to the incubation mixture inhibited dihydrodiol formation in rat and mouse preparations by 90 per cent, and in guinea pig preparations by 70 per cent. Phenols and phenanthrene — 9,10 — oxide were produced instead.