The Role of the Steroid-Sensitive Cation-Dependent Atpase in Human Prostatic Tissue

SUMMARY The purposes of this study were: (1) to determine if a (Na + + K + )-dependent, ouabain-sensitive, androgen-responsive ATPase is present in the microsomal fraction of the human prostate as it is in the rat ventral prostate; (2) to determine the degree and nature of interaction and interdependence of the ATPase with the steroid-binding and steroid-metabolizing activities of the prostate and, also, with the histological characteristics of the gland. The results indicate that ATPase which shows particular responsiveness to 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol and dehydroepiandrosterone is present. The microsomes, which contain this enzymic activity, show relatively high affinity for the active steroids and for oestradiol-17β. The intrinsic steroid-sensitive, cation-dependent ATPase activity varies widely from gland to gland in parallel with the steroid binding and 3α-hydroxysteroid dehydrogenase activity. In comparisons of the enzymatic complements of glands with different histological features, the concentration of 4-en-3-oxosteroid-5α-reductase activity in tissue showing predominantly epithelial hyperplasia was greater than that in normal or carcinomatous glands or glands with stromal hypertrophy. The possible role of the ATPase as a mediator of hormonal stimulation, and the implications of the findings to an understanding of the development of benign prostatic hypertrophy, are discussed.