Apparent mineralocorticoid excess syndromes.
Apparent mineralocorticoid excess (AME) is a syndrome attributable to congenital deficiency of the enzyme 11 beta-dehydrogenase (11 beta-OHSD) which converts active glucocorticoid cortisol to inactive cortisone. When 11 beta-OHSD activity is impaired, cortisol acts as a potent mineralocorticoid and causes hypertension and hypokalemia with a suppression of the renin-angiotensin-aldosterone system. The increased ratio of urinary cortisol/cortisone metabolites and a prolonged half-life of cortisol are useful for the diagnosis. Dexamethasone and/or potassium sparing diuretics have been used for medication of AME. Licorice ingestion induces a mineralocorticoid excess state, and it seems that this is the result of acquired inhibition of 11 beta-DH by glycyrrhetinic acid. The existence of a second 11 beta-OHSD isoform has been suggested strongly for a long time, and recently, a human 11 beta-OHSD 2 cDNA has been isolated. It appears that 11 beta-OHSD 2 conveys specificity upon the renal MR, and a defect in its activity seems likely to account for the phenotype of AME.
Shimojo
M
M
Department of Medicine, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, England.
Stewart
P M
PM
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000818:Animals; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D006913:Hydroxysteroid Dehydrogenases / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D006973:Hypertension / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D007008:Hypokalemia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D008901:Mineralocorticoids / Q000096:biosynthesis / Q000378:metabolism* / Q000502:physiology; D013577:Syndrome
D008901:Mineralocorticoids; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D006854:Hydrocortisone