Pathways for Androgen Synthesis in Vitro by the Testes of Japanese Quail (Coturnix Coturnix Japonica)

Abstract

The microsomal fraction of testicular tissue from Japanese quail (Coturnix coturnix japonica) was incubated with 4-14C-labelled pregnenolone, progesterone, 17\g=a\-hydroxyprogesterone,androstenedione, dehydroepiandrosterone and testosterone and [7-3H]17\g=a\-hydroxypregnenolone in a medium containing either NAD or NADPH. The metabolic products were identified by their mobilities on thin-layer chromatograms, derivative formation after oxidation and acetylation of the metabolites, and recrystallization to constant specific activity.Three pathways for testosterone formation by the testes are suggested by the results: the first via progesterone, 17\g=a\-hydroxyprogesterone and androstenedione; the second via 17\g=a\-hydroxypregnenolone,dehydroepiandrosterone and androstenedione; and the third via 17\g=a\-hydroxypregnenolone, dehydroepiandrosterone and androst-5-ene-3\g=b\,17\g=b\-diol.