The 7β-hydroxylation of 3β-hydroxyandrost-5-en-17-one by hepatic microsomes

A metabolite isolated after the incubation of 3β-hydroxyandrost5-en-17-one with rabbit-liver microsomal fractions has been characterized as 3β,7β-dihydroxyandrost-5-en-17-one. The transformation is not an autoxidation and, since 3β, 7α-dihydroxyandrost-5-en-17-one and 3β-hydroxyandrost-5-ene-7,17-dione failed to give comparable yields, a direct 7β-hydroxylation is probably involved. Species differences were observed in the 7-hydroxylating activities of hepatic microsomes from rhesus, rat and rabbit liver, but these activities were comparable in microsomal subfractions from either sex.