Structure and steroidogenic enzymes of the seminal vesicles of the urohaze-goby (Glossogobius olivaceus).

The in vitro steroid metabolism in the seminal vesicles of the brackish water goby (urohaze-goby, Glossogobius olivaceus) was studied using males in the breeding season. The moderate activity of delta 5-3 beta-hydroxysteroid dehydrogenase was histochemically detected only in the epithelial cells of the organ, though these cells have the characteristics of secretory cells ultrastructurally. Cell-free homogenates (800 g supernatant fluid) of the whole tissue were aerobically incubated with 14C-labeled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone, androstenedione, dehydroepiandrosterone, or testosterone in the presence of NAD+ or NADPH. Pregnenolone and dehydroepiandrosterone were converted to progesterone and androstenedione, respectively. Progesterone was transformed to 5 alpha-pregnane-3,20-dione (main product) and 17 alpha-hydroxyprogesterone. 17 alpha-Hydroxyprogesterone was metabolized into androstenedione (main product) and 17 alpha-hydroxy-5 alpha-pregnane-3,20-dione. From androstenedione, 5 alpha-androstane-3,17-dione (main product) and epiandrosterone were obtained. Testosterone was transformed to 5 alpha-dihydrotestosterone, 5 alpha-androstane-3 beta, 17 beta-diol, 5 alpha-androstane-3,17-dione, and androstenedione. These results indicate that the steroid metabolic patterns in the seminal vesicles of G. olivaceus are closely resembled to those in the testes.