Steroid hormones and hypertension: The cortisol-cortisone shuttle

Abstract

The role of adrenal steroid hormones in hypertension has, until recently, focused on disorders of secretion. We describe a new form of mineralocorticoid hypertension which arises from impaired metabolism of physiological glucocorticoid. 11 β-hydroxysteroid dehydrogenase (11 β-HSD) is responsible for the inactivation of cortisol to cortisone. Congenital absence of this enzyme (the syndrome of apparent mineralocorticoid excess) results in cortisol acting as a potent mineralocorticoid. Furthermore, inhibition of this enzyme by glycyrrhizic and glycyrrhetinic acids also accounts for the mineralocorticoid excess states seen following licorice and carbenoxolone ingestion. Whilst impaired 11 β-HSD activity has been shown in patients with “essential” hypertension, the significance of this finding remains unknown. These clinical studies, however, have uncovered a novel physiological mechanism, whereby the mineralocorticoid receptor (which in vitro has an equal affinity for cortisol and aldosterone) is protected from cortisol excess by the action of 11 β-HSD. Thus 11 β-HSD plays a crucial role in determining the in vivo specificity for this receptor. (Steroids 58:614–620, 1993)