Histochemical studies on steroid dehydrogenases in the testis of the goat (Capra hircus)

Abstract
Detailed histochemical localization of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-HSD was made in the goat testis using both NAD and NADP coenzymes. The substrates used for 3β-HSD were dehydroepiandrosterone (DHA) and pregnenolone whereas 17β-HSD was localized with testosterone and oestradiol. In general, the activity of the enzymes varied with the cell type, substrate and coenzyme. In seminiferous tubules, DHA and NAD were the preferred substrate and coenzyme respectively for 3β-HSD. In addition, in interstitial tissue, NAD was the preferred coenzyme with DHA whereas no such preference existed with pregnenolone. 17β-Hydroxysteroid dehydrogenase showed a similar pattern in the two main compartments of the testis, as testosterone and oestradiol were equally utilized and NAD was the preferred coenzyme in both these compartments. The activities of the enzymes increased during the process of spermiogenesis and were higher in seminiferous tubules than in interstitial tissue, especially in elongated spermatids and spermatozoa. J. Endocr. (1984) 101, 359–363