Adamski J, Hohls E, Jungblut P W
Max-Planck-Institut für experimentelle Endokrinologie, Hannover, Germany.
Exp Clin Endocrinol. 1994;102(5):388-93. doi: 10.1055/s-0029-1211309.
The oxidation of estradiol to estrone in porcine endometrial cells is succeeded by hydroxylation at either 6 alpha- or 7 alpha-. The products are devoid of receptor affinity. Their formation is inhibited by cytochrome P450 blockers like ketoconazol but not by chloroquine and analogues. The hydroxylation at 6 alpha- proceeds with KM = 1.9 x 10(-7) M, that at 7 alpha- with KM = 3.6 x 10(-7) M. The respective values for the cytochrome P450-reductase cosubstrate NADPH are 1.7 x 10(-5) M and 1.9 x 10(-5) M. The kinetic parameters of the enzymes are compatible with a metabolic sequence: estradiol-->estrone--> 6 alpha/17 alpha-estrone.
在猪子宫内膜细胞中，雌二醇氧化为雌酮后接着会在6α-或7α-位发生羟基化。这些产物没有受体亲和力。它们的形成受到酮康唑等细胞色素P450阻断剂的抑制，但不受氯喹及其类似物的抑制。6α-位的羟基化反应的米氏常数（KM）为1.9×10⁻⁷ M，7α-位的羟基化反应的KM为3.6×10⁻⁷ M。细胞色素P450还原酶的共底物烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的相应值分别为1.7×10⁻⁵ M和1.9×10⁻⁵ M。这些酶的动力学参数与以下代谢顺序相符：雌二醇→雌酮→6α/17α-雌酮。
