11beta-hydroxysteroid dehydrogenases: changing glucocorticoid action.

11beta-hydroxysteroid dehydrogenases (11beta-HSDs) catalyse the interconversion of active cortisol and inert cortisone. Two isozymes have been discovered, each with unique properties and powerful biological roles. 11beta-HSD2 potently inactivates cortisol, protecting key tissues. By contrast, 11beta-HSD1 regenerates cortisol, amplifying its actions in liver, fat and brain. Overexpression of this isozyme may contribute to the pathogenesis of the metabolic syndrome. Its inhibition is a potential therapeutic target for both metabolic and glucocorticoid-associated CNS disorders.