In vitro metabolism of testosterone by gonads of the grouper (Epinephelus tauvina) before and after sex inversion with 17 alpha-methyltestosterone.

The steroidogenic potential of gonadal tissues of the protogynous grouper (Epinephelus tauvina) was examined before and after sex inversion with 17 alpha-methyltestosterone. Incubations of gonadal tissues of the fish with [3H]testosterone resulted in the biosynthesis of 5 beta-androstane-3 beta, 17 beta-diol and 5 beta-dihydrotestosterone as the only metabolites in the female phase. Although the production of these 5 beta-reduced androgens persisted in the male phase, there was a shift toward the production of 11 beta-hydroxytestosterone and 11-ketotestosterone as major metabolites.