Seckl J R
University of Edinburgh, Department of Medicine, Western General Hospital, UK.
Eur J Clin Invest. 1993 Oct;23(10):589-601. doi: 10.1111/j.1365-2362.1993.tb00720.x.
11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) catalyzes the reversible conversion of physiological glucocorticoids (cortisol, corticosterone) to inactive products. The enzyme thus protects non-selective renal mineralocorticoid receptors from circulating glucocorticoids (ensuring aldosterone-selectivity in vivo), excludes maternal glucocorticoids from the foetal circulation and modulates glucocorticoid access to glucocorticoid receptors in other tissues. 11 beta-HSD has been purified from rat liver, antisera raised, a cDNA isolated and its human homologue cloned. However, it is difficult to reconcile all of the actions of 11 beta-HSD with a single enzyme. Here data are reviewed that demonstrate not only molecular heterogeneity of the 'liver-type' 11 beta-HSD, but also the existence of a novel high affinity isoform in the placenta and perhaps distal nephron. These data are discussed in the light of their potential physiological and pathological importance, with particular reference to the pathogenesis of hypertension.
11β-羟基类固醇脱氢酶（11β-HSD）催化生理性糖皮质激素（皮质醇、皮质酮）可逆转化为无活性产物。该酶因此保护非选择性肾盐皮质激素受体免受循环糖皮质激素的影响（确保体内醛固酮选择性），将母体糖皮质激素排除在胎儿循环之外，并调节糖皮质激素进入其他组织中的糖皮质激素受体。11β-HSD已从大鼠肝脏中纯化出来，制备了抗血清，分离出了cDNA并克隆了其人类同源物。然而，很难用单一一种酶来解释11β-HSD的所有作用。本文综述了相关数据，这些数据不仅证明了“肝型”11β-HSD的分子异质性，还证明了胎盘以及可能在远曲小管中存在一种新型高亲和力同工型。鉴于这些数据潜在的生理和病理重要性进行了讨论，特别提及了高血压的发病机制。
