Satoh T, Watanabe K, Takanashi K, Itoh S, Takagi H, Yoshizawa I
Hokkaido Institute of Pharmaceutical Sciences, Japan.
J Pharmacobiodyn. 1992 Aug;15(8):427-36. doi: 10.1248/bpb1978.15.427.
Ring A aromatization of testosterone sulfate (TS), using human term placental microsomes as a enzyme source, was examined under a reduced nicotinamide adenine dinucleotide phosphate (NADPH)-generating system. The aromatization to estradiol 17-sulfate (ES) without removal of the C-17 conjugate group was confirmed. Judging from the results of various experiments, including an inhibition experiment, the conversion was considered to occur by placental aromatase. Apparent Km and Vmax values for this aromatization were determined to be 37.4 microM and 330 pmol/mg protein/min respectively. The physiological role of direct conversion of TS by placenta to ES is discussed in connection with pregnancy.
在还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）生成系统下，以人足月胎盘微粒体作为酶源，对硫酸睾酮（TS）的A环芳香化反应进行了研究。证实了在不去除C-17共轭基团的情况下，可将其芳香化为17-硫酸雌二醇（ES）。从包括抑制实验在内的各种实验结果判断，该转化被认为是由胎盘芳香化酶催化的。该芳香化反应的表观米氏常数（Km）和最大反应速度（Vmax）值分别测定为37.4微摩尔/升和330皮摩尔/毫克蛋白/分钟。结合妊娠情况讨论了胎盘将TS直接转化为ES的生理作用。
