THE ACTIVITIES OF 5-BETA-REDUCTASE AND 11-BETA-HYDROXYSTEROID DEHYDROGENASE IN ESSENTIAL-HYPERTENSION

The activities of 11 beta-hydroxysteroid dehydrogenase(11 beta-HSD) an d 5 beta-reductase were analyzed in 39 normotensive controls and 128 p atients with essential hypertension. The activity of 11 beta-HSD was o btained by dividing the 24-hour urinary tetrahydrocortisone by the sum of tetrahydrocortisol (THF) and allo-tetrahydrocortisol (aTHF), where as the activity of 5 beta-reductase was obtained by dividing the 24-ho ur urinary THF by aTHF. The activity of 5 beta-reductase was significa ntly lower in essential hypertensives compared with normotensive contr ols (P < 0.05). However, the activity of 11 beta-HSD did not differ be tween normotensive controls and essential hypertensives. A positive co rrelation between the activities of 11 beta-HSD and 5 beta-reductase w as observed in essential hypertensives (r = 0.60, P < 0.01). Neither 1 1 beta-HSD nor 5 beta-reductase activity correlated with indices of re nal mineralocorticoid receptor activation, which were assessed by dete rmination of plasma potassium and urinary excretion of sodium as well as potassium. Taken together, these results suggest that disturbances of one of the inactivation pathways of cortisol may contribute to the pathogenesis of hypertension.