11beta-hydroxysteroid dehydrogenase in human vascular cells.

Aldosterone selectivity in mineralocorticoid target tissues is mainly due to 11beta-hydroxysteroid dehydrogenase (11betaHSD), which converts cortisol to its inactive metabolite cortisone in humans. The defect of dehydrogenase activity would thus allow type 1 mineralocorticoid receptor (MR) to be occupied mostly by cortisol. It has been postulated that 11betaHSD type 2 (11betaHSD2) plays a significant role in conferring ligand specificity on the MR.