Mineralocorticoid activity of 16beta-hydroxydehydroepiandrosterone and related steroids.

16beta-Hydroxydehydroepiandrosterone (16beta-OH-DHEA) and related C19-steroids have recently been reported to be etiologic in low-renin essential hypertension. The mineralocorticoid potency of 16beta-OH-DHEA and several C19-steroids (16-oxo-A-diol, 16-oxo-testosterone, 16beta-OH-epiandrosterone, 5-androstene-3beta, 16beta,17beta-triol, 19beta-OH-testosterone, 18-OH-DHEA, and 16alpha-OH-DHEA) were investigated in two different rat bioassay systems under a variety of experimental conditions. In all but one instance, only negligible mineralocorticoid activity was observed, usually less than 0.1 per cent that of aldosterone. Since 16beta-OH-DHEA has negligible mineralocorticoid activity in the rat bioassay and the toad bladder assay (as reported by others), does not cause hypertension when injected chronically into the rat, and does not displace aldosterone from its renal receptors, it appears unlikely to be etiologic in low-renin essential hypertension. On the other hand, when 16-oxo-testosterone was injected intraperitoneally instead of subcutaneously, it demonstrated a slight increase in mineralocorticoid activity (from less than 0.1 per cent to 0.2 per cent) which equaled that of 18-hydroxydeoxycorticosterone (18-OH-DOC) injected subcutaneously. Thus, the possibility remains that 16-oxo-testosterone or a closely related metabolite may have sufficient mineralocorticoid activity to be involved in certain forms of hypertension in man.