Enzymatic Oxidation and Reduction of C19Δ5, 3β-Hydroxysteroids by Hepatic Microsomes. I. Biosynthesis of 3β,17β-Dihydroxyandrost-5-en-16-one and Sex Differences in Adult Rats1
Incubation of 14C-4-dehydroepiandrosterone (DHA) with liver microsomes from adult Sprague-Dawley rats led to the biosynthesis of 3β,17β-dihydroxyandrost-5-en-16-one (16-keto- A5-diol), along with the expected products, androst- 5-ene-3β,17β-diol (A5-diol), 3β,l6α-dihydroxyandrost- S-en-17-one (16a-0H-DHA), and androst-5-ene-3β,16α,17β-triol (A5-triol). The identity of 16-keto-A5-diol was established by the chromatographic properties of the free and acetylated compounds and by recrystallization to constant SA. Optimal incubation conditions for the biosynthesis of the 16,17-isomeric ketols yielded 16-keto-A5-diol as the predominant isomer. The production of 16-keto-A5-diol is sex-linked as is that of 16α-OH-DHA and A5-triol, with higher yields from males. The rate of biosynthesis of A5-diol is the same for both sexes. (Endocrinology91: 969, 1972)