人皮肤中3-β-羟基类固醇脱氢酶/δ5-4-异构酶的活性与抑制作用

Activity and inhibition of 3-beta-hydroxysteroid dehydrogenase/delta-5-4-isomerase in human skin.

作者信息

Tóth I, Szécsi M, Julesz J, Faredin I

机构信息

Endocrine Unit, Albert Szent-Györgyi Medical University, Szeged, Hungary.

出版信息

Skin Pharmacol. 1997;10(3):160-8. doi: 10.1159/000211481.

DOI:10.1159/000211481

PMID:9287397

Abstract

Activity and inhibition of 3 beta-hydroxysteroid dehydrogenase/delta 5-4-isomerase, a key example of biosynthesis of androgenic steroids, in human skin were studied. Whole-width dermal tissue specimens excised from various regions of the male and female body were investigated with an in vitro radioenzyme assay method using dehydroepiandrosterone as substrate. The Michaelis-Menten constant of the enzyme was found to be Km = 10nM and the maximal velocity was Vmax = 0.625 pmol produced 4-androstene-3,17-dione/mg protein/20 min. Activity of 3 beta-hydroxysteroid dehydrogenase/delta 5-4-isomerase in male inguinal skin (n = 8) was 0.132-0.412, in female abdominal skin (n = 4) 0.140-0.255, in perineal skin (n = 4) 0.138-0.962 pmol/mg protein/20 min. The synthetic steroids cyproterone acetate, 4-MA and epostane proved to be potent inhibitors, IC50 values were 150, 6.2 and 1.45 nM, respectively.

摘要

对人类皮肤中3β-羟基类固醇脱氢酶/δ5-4-异构酶（雄激素类固醇生物合成的一个关键实例）的活性及抑制作用进行了研究。采用体外放射酶分析法，以脱氢表雄酮为底物，对从男性和女性身体不同部位切除的全层真皮组织标本进行了研究。发现该酶的米氏常数为Km = 10nM，最大反应速度为Vmax = 0.625 pmol生成4-雄烯-3,17-二酮/毫克蛋白质/20分钟。3β-羟基类固醇脱氢酶/δ5-4-异构酶在男性腹股沟皮肤（n = 8）中的活性为0.132 - 0.412，在女性腹部皮肤（n = 4）中为0.140 - 0.255，在会阴皮肤（n = 4）中为0.138 - 0.962 pmol/毫克蛋白质/20分钟。合成类固醇醋酸环丙孕酮、4-MA和依普斯坦被证明是有效的抑制剂，IC50值分别为150、6.2和1.45 nM。