Steroid hydroxylations by human adrenal cortex microsomes 1, 2.
Steroid hydroxylations by human adrenal cortex microsomes 1, 2.
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人肾上腺皮质微粒体的类固醇羟基化 1, 2。
DOI：
10.1210/jcem-41-1-7
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
G. Bryan
中科院分区：
文献类型：
--
作者：
E. Nelson;G. Bryan
从尸体肾移植时获得的人肾上腺制备微粒体。测定微粒体的细胞色素P-450浓度（平均值=0.63 nmol/mg蛋白）和NADPH-细胞色素c还原酶活性（平均值65 nmol × min-1 × mg-1蛋白）。类固醇羟基化率进行了测量。在人类中，17-羟孕酮的21-羟基化速率约为孕酮21-羟基化速率的3倍。孕酮的17-羟基化速率大约是孕酮的21-羟基化速率的三倍。底物与微粒体的结合显示孕酮和17-羟基孕酮的I型谱。两种底物均结合所有光谱可识别位点。针对猪NADPH-细胞色素c还原酶制备的抗体同时抑制人还原酶、孕酮和17-羟孕酮的21-羟基化和孕酮的17-羟基化。将这些结果与先前使用牛肉肾上腺微粒体的研究进行了比较。未获得表明人肾上腺微粒体中存在多种形式21-羟化酶的具体证据。似乎人类肾上腺微粒体细胞色素P-450电子传递链在免疫学上与以前研究的那些相似-牛肉肾上腺，大鼠和人类肝脏。
Microsomes were prepared from human adrenals obtained at the time of cadaveric renal transplantation. Microsomes were assayed for cytochrome P-450 concentrations (mean =0.63 nmol/mg protein) and NADPH-cytochrome c reductase activity (mean 65 nmol times min-1 times mg-1 protein). Rates of steroid hydroxylation were measured. In man, the rate of 21-hydroxylation of 17-hydroxyprogesterone was approximately three times the rate of 21-hydroxylation of progesterone. The rate of 17-hydroxylation of progesterone was approximately three times the rate of 21-hydroxylation of progesterone. Substrate binding to microsomes showed a type I spectrum with progesterone and 17-hydroxy-progesterone. Both substrates bound all spectrally identifiable sites. Antibody prepared against procine NADPH-cytochrome c reductase inhibited concomitantly human reductase, 21-hydroxylation of progesterone and 17-hydroxyprogesterone, and 17-hydroxylation of progesterone. These results were compared to previous studies with beef adrenal microsomes. No specific evidence was obtained to suggest multiple forms of 21-hydroxylase in human adrenal microsomes. It appears as though the human adrenal microsomal cytochrome P-450 electron transport chain is immunologically similar to those studied previously--beef adrenal, and rat and human liver.