Steroid 5α-Reductase Activity, Androgen Level and Its Receptor in the Target Tissues of Male Fetuses
Yu-Gui CUI1, Gui-Yuan ZHANG2 (1. Department of Endocrinology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China; 2. National Research Institute of Family Planning, Beijing 100081, China)
Objectives: To measure the 5α-reductase activity, androgen (testosterone and dihydrotestosterone, T and DHT) levels and the ligand binding capacity of androgen receptor (AR) in the androgen target tissues-genital skin of male fetuses, and evaluate the effect of androgen on the sexual differentiation and development. Methods: Four samples of foreskins were acquired from four male fetuses with consent at the pregnancy age of 16～20 weeks who had been aborted due to emergency accident. As control, the foreskins were obtained from 10 male children aged 4 to 7 ys and 23 adult men aged 20 to 34 ys when circumcision due to phimosis. T and DHT levels were measured with the method of RIA. 5α-reductase activity and AR binding capacity were assayed with the methods developed in our laboratory. Results: In male fetuses, T level in target tissues was (4.55±2.84)pmol/(mg protein·ml), DHT (39.12±17.30) pmol/(mg protein·ml); 5α-reductase type Ⅰ activity (162.15±36.94)pmol/(mg protein·30min), type Ⅱ (307.62±40.55)pmol/(mg protein·30min); the ligant binding capacity of cytosole AR (18.86±7.62)fmol/mg protein, nuclear AR (108.55±49.34) fmol/mg protein. These data were higher than those in male children and adult men (P0.05～0.01), except for AR capacity. Conclusions: Androgen and AR, as well as 5α-reductase, were at the high status in male fetuses, suggesting that androgen, especially DHT, played an important role in regulating the sexual differentiation and development.
【CateGory Index】： R321