Distinguishing the activities of 11β-hydroxysteroid dehydrogenases in vivo using isotopically labeled cortisol
Distinguishing the activities of 11β-hydroxysteroid dehydrogenases in vivo using isotopically labeled cortisol
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DOI：
10.1210/jc.87.1.277
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发表时间：
2002-01-01
影响因子：
5.8
通讯作者：
Walker, BR
中科院分区：
文献类型：
--
作者：
Andrew, R;Smith, K;Walker, BR
11 β-羟基类固醇脱氢酶（11 β-hydroxysteroid dehydrogenase，11 β-HSDs）的同工酶催化皮质醇和可的松的相互转化。2型脱氢酶使皮质醇失活为可的松，而1型脱氢酶主要催化逆还原反应。这些反应发生在不同的组织中，在那里它们受到不同的调节，并且在常见的病理学中可能是重要的。目前测定这些酶活性的方法仅依赖于皮质醇和可的松之间的平衡，不测量周转，并且不能区分这两种反应。我们研究了使用[9，11，12，12-（2）H（4）]皮质醇（d4 F）来区分脱氢酶和还原酶活性。在脱氢代谢过程中，d4 F失去11 α-氘，形成三氘代可的松（ME），并通过还原再生为三氘代皮质醇（d3 F）。健康男性（n = 6）参加了一项随机、双盲、交叉研究，比较口服安慰剂和11 β HSD抑制剂甘珀酸（100 mg，每8 h，持续7 d）。在稳态输注期间测量血浆和尿液中的d4 F及其代谢物。甘珀酸对11 β-HSDs的抑制作用通过增加d4 F的稳态浓度（41 +/- 5.1 vs. 48 +/- 7.7 nm; P < 0.05）和降低d3 F的出现率（P < 0.05）来测量。11 β HSD 1还原酶活性可以通过d3 E向d3 F的转化来具体测量（28 +/- 4.2 vs. 17 +/- 3.1 nm; P < 0.05），而11 β HSD 2可通过d3 E的初始出现率或尿d4 F/（d3 E + d3 F）（0.73 +/- 0.06 vs.1.02 +/- 0.03; P < 0.05）。该技术在人体研究中提供了可用于测量11 β HSDs和11 β HSDs同工酶的体内转换的方法的显著进步，并且该研究证实了甘珀酸抑制11 β HSDs的两种同工酶。
The isozymes of 11beta-hydroxysteroid dehydrogenase (11betaHSDs) catalyze the interconversion of cortisol and cortisone. The type 2 dehydrogenase inactivates cortisol to cortisone, whereas the type 1 catalyzes predominantly the reverse reductive reaction. These reactions take place in different tissues, where they are subject to distinct regulation, and may be important in common pathologies. Current methods to determine the activities of these enzymes in vivo rely only on the balance between cortisol and cortisone, do not measure turnover, and cannot distinguish between the two reactions.We have investigated the use of [9,11,12,12-(2)H(4)]cortisol (d4F) to distinguish the dehydrogenase and reductase activities. On metabolism by dehydrogenation, d4F loses 11alpha-deuterium, forming trideuterated cortisone (ME) and is regenerated by reduction to trideuterated cortisol (d3F). Healthy men (n = 6) participated in a randomized, double blind, cross-over study comparing oral placebo and the 11betaHSD inhibitor, carbenoxolone (100 mg every 8 h for 7 d). d4F and its metabolites were measured in plasma and urine during a steady state infusion. Inhibition of 11betaHSDs by carbenoxolone was measured by increased steady state concentrations of d4F (41 +/- 5.1 vs. 48 +/- 7.7 nm; P < 0.05) and a fall in he rate of appearance of d3F (P < 0.05). 11betaHSD1 reductase activity could be measured specifically as conversion of d3E to d3F (28 +/- 4.2 vs. 17 +/- 3.1 nm; P < 0.05), whereas 11betaHSD2 could be measured by initial rates of appearance of d3E or from urinary ratios of d4F/(d3E + d3F) (0.73 +/- 0.06 vs. 1.02 +/- 0.03; P < 0.05).This technique offers a significant advance in the methods available to measure turnover in 11betaHSDs and isozymes of 11betaHSDs in vivo in human studies, and this study confirms that carbenoxolone inhibits both isozymes of 11betaHSD.