Pathophysiology of modulation of local glucocorticoid levels by 11 beta-hydroxysteroid dehydrogenases

11 beta -Hydroxysteroid dehydrogenases (11 beta HSDs) are enzymes that cata lyse the interconversion of active glucocorticoids (cortisol and corticoste rone) into their inactive 11-keto products (cortisone and 11-deoxycorticost erone). Two isozymes have been identified: 11 beta HSD type 1 is a predomin ant reductase, reactivating glucocorticoids from inert metabolites, whereas 11 beta HSD type 2 is a potent dehydrogenase, inactivating glucocorticoids . They play a major role in the modulation of local cortisol levels and hen ce access of active steroid to corticosteroid receptors. This review focuse s on the clinical importance of 11 beta HSDs. We describe recent research t hat has not only advanced our understanding of the physiological role of th ese enzymes, but also their role in common diseases, including primary obes ity and essential hypertension. These data provide encouragement that novel therapies will arise from a fuller understanding of the 11 beta HSD system .