11Beta Hydroxysteroid dehydrogenase

11-Beta Hydroxysteroid Dehydrogenase (HSD11B) is the name of a family of enzymes that catalyzes the conversion of inert 11 keto-products (cortisone) to active cortisol, or vice versa, thus regulating the access of glucocorticoids to the steroid receptors.

In humans, there are two HSD11B isoforms:
 * 1) HSD11B1 is NADPH-dependent. Highly expressed in key metabolic tissues including liver, adipose tissue, and the central nervous system. In these tissues, HSD11B1 reduces cortisone to the active hormone cortisol that activates glucocorticoid receptors.
 * 2) HSD11B2 is NAD+-dependent. Expressed in aldosterone-selective tissues. In these tissues, HSD11B2 oxidizes cortisol to cortisone and prevents illicit activation of the mineralocorticoid receptor.