The 11-Beta Hydroxysteroid Dehydrogenase System

The 11-Beta Hydroxysteroid Dehydrogenase System

11-Beta Hydroxysteroid Dehydrogenase (11-β HSD) is an enzyme involved in steroid hormone physiology. It has two isoforms, type 1 and type 2, expressed in humans by glucocorticoid and mineralocorticoid target cells, respectively. Type 1 converts inactive cortisone to active cortisol, and type 2 does the inverse. These glucocorticoids (cortisone and cortisol) circulate in the bloodstream at much higher concentrations than the mineralocorticoid aldosterone. Because the minerolocorticoid receptor  may be activated by either aldosterone or cortisol, the presence of 11-β HSD type 2 protects it from continuous activation by decreasing local cortisol levels. This is shown on the lefthand side of the image. Meanwhile on the right, 11-β HSD type 1 enhances the activation of the glucocorticoid receptor by increasing local cortisol levels.

 

The 11-β HSD System | 2011 | Portfolio, Scientific | Tags: , , ,