Cortisol , a glucocorticoid, binds the glucocorticoid receptor. However, because of its molecular similarity to aldosterone it is also capable of binding the mineralcorticoid receptor. Both aldosterone and cortisol have a similar affinity for the mineralocorticoid receptor; however, there is vastly more cortisol in circulation than aldosterone. To prevent over-stimulation of the mineralocorticoid receptor by cortisol, HSD-11β converts the biologically active cortisol to the inactive cortisone, which can no longer bind to the mineralocorticoid receptor. 11β-HSD co-localizes with intracellular adrenal steroid receptors. Licorice , which contains glycyrrhetinic acid , or enoxolone can inhibit 11β-HSD and lead to a mineralocorticoid excess syndrome .
"The whole body 11bHSD1 activity reflects mainly hepatic expression. Initial studies that relied on measurements of cortisol-to-cortisone metabolites in urine (23,36) should be taken with caution as indicative of 11bHSD1 activity, because several other cortisol and cortisone metabolizing enzymes are deregulated in obesity (36). Of greater importance is the finding of reduced hepatic 11bHSD1 activity measured by the conversion of orally administered cortisone to cortisol (23,37). Thus, 11bHSD1 upregulation in obesity seems not to be a generalized process. In both the whole body and the splanchnic circulation there are no differences between obese and lean subjects regarding cortisol regeneration rates (as measured by [2H4]-cortisol tracer), presumably because an upregulation in adipose tissue is counterbalanced by a downregulation in the liver (15).