The role of 11 beta-hydroxysteroid dehydrogenase in the pathogenesis of hypertension.
The two 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) isozymes catalyze the interconversion of cortisol and cortisone. Type 1 11 beta-HSD (11 beta-HSD1) has bidirectional activity, while type 2 11 beta-HSD (11 beta-HSD2) mainly converts cortisol into cortisone. Of these two hormones only cortisol has affinity to mineralocorticoid receptors (MRs) and thus induces mineralocorticoid effects. A normal activity of 11 beta-HSD2 is crucial for prevention of mineralocorticoid activity of cortisol. Absent or decreased 11 beta-HSD2 activity results in cortisol-mediated hypermineralocorticoid hypertension. In several hypertensive syndromes a decreased 11 beta-HSD2 activity has been described as the pathogenetic mechanism of the increased blood pressure. In the apparent mineral corticoid excess (AME) syndrome type 1, absence of 11 beta-HSD2 activity is caused by mutations in the gene coding for 11 beta-HSD2. In licorice-induced hypertension glycyrrhetinic acid, the active substituent of licorice, inhibits 11 beta-HSD2 resulting in an acquired hypermineralocorticoid state. 11 beta-HSD2 activity is not decreased in glucocorticoid hypertension (Cushing's syndrome). In essential hypertension some evidence for decreased systemic and skin activity of 11 beta-HSD1 and/or 11 beta-HSD2 has been found, while renal activity of both isozymes appears to be normal. 11 beta-HSD2 activity is also present in cardiovascular myocytes of humans and dogs, and inhibition of 11 beta-HSD potentiates the vascular response to catecholamines. Although MRs in the central nervous system have been incriminated in the pathogenesis of mineralocorticoid hypertension, a pathophysiological role for 11 beta-HSD2 has not yet been described. Finally, in the placenta 11 beta-HSD2 reduces fetal exposure to maternal glucocorticoids and a decreased activity of this isozyme may result in low birth weight and increased risk of high blood pressure at adult age.
Department of Medicine, St. Radboud University Hospital, University of Nijmegen, Netherlands. s.vanuum@aig.azn.nl
S H
SH
van Uum
A R
AR
Hermus
P
P
Smits
T
T
Thien
J W
JW
Lenders
D042842:11-beta-Hydroxysteroid Dehydrogenases; D003348:Cortisone / Q000378:metabolism; D006034:Glycyrrhetinic Acid / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D006913:Hydroxysteroid Dehydrogenases / Q000502:physiology*; D006973:Hypertension / Q000201:enzymology*; D007527:Isoenzymes / Q000502:physiology; D018161:Receptors, Mineralocorticoid / Q000378:metabolism
D007527:Isoenzymes; D018161:Receptors, Mineralocorticoid; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D006034:Glycyrrhetinic Acid; D003348:Cortisone; D006854:Hydrocortisone