人肝脏中乙炔雌二醇的硫酸化和葡萄糖醛酸化（体外研究）

Sulphation and glucuronidation of ethinyloestradiol in human liver in vitro.

作者信息

Pacifici G M, Back D J

机构信息

Department of Pharmacology and Therapeutics, University of Liverpool, England.

出版信息

J Steroid Biochem. 1988 Sep;31(3):345-9. doi: 10.1016/0022-4731(88)90360-3.

DOI:10.1016/0022-4731(88)90360-3

PMID:3138501

Abstract

The sulphotransferase and the glucuronyltransferase activities were measured with [3H]ethinyloestradiol in vitro using subcellular fractions from human liver. A rapid and sensitive assay based on a single extraction in ether of the unmetabolized EE2 is described. The mean (+/- SD) of the sulphotransferase and glucuronyltransferase activities from 8 livers was 68.2 +/- 16.5 and +/- 190.4 +/- 82.3 pmol/min/mg, respectively. The kinetic parameters of both enzymes were measured in 4 livers by varying the concentrations of EE2 or the endogenous substrate. At varying concentrations of EE2 the average (+/- SD) of Vmax was 66.5 +/- 15.8 pmol/min/mg (sulphotransferase) and 404 +/- 317 pmol/min/mg (glucuronyltransferase). The mean (+/- SD) of Km was 0.0072 +/- 0.0019 mM (sulphotransferase) and 0.20 +/- 0.12 mM (glucuronyltransferase).

摘要

使用人肝脏的亚细胞组分，在体外以[3H]乙炔雌二醇测定磺基转移酶和葡糖醛酸基转移酶的活性。描述了一种基于单次乙醚萃取未代谢的EE2的快速灵敏测定法。来自8个肝脏的磺基转移酶和葡糖醛酸基转移酶活性的平均值（±标准差）分别为68.2±16.5和190.4±82.3 pmol/分钟/毫克。通过改变EE2或内源性底物的浓度，在4个肝脏中测量了两种酶的动力学参数。在不同浓度的EE2下，Vmax的平均值（±标准差）为66.5±15.8 pmol/分钟/毫克（磺基转移酶）和404±317 pmol/分钟/毫克（葡糖醛酸基转移酶）。Km的平均值（±标准差）为0.0072±0.0019 mM（磺基转移酶）和0.20±0.12 mM（葡糖醛酸基转移酶）。