Kühn-Velten N, Staib W
J Steroid Biochem. 1984 Feb;20(2):555-61. doi: 10.1016/0022-4731(84)90123-7.
The effects of single administration to adult male rats in vivo of various amounts of human chorionic gonadotropin (HCG) and of single or repeated injections of estradiol on testicular cytoplasmic estradiol binder concentrations and on microsomal progesterone-binding cytochrome P-450 were compared. Half-life periods of HCG-induced loss of estradiol binder and cytochrome P-450 concentrations are identical (6 h) whereas a strong dissociation of these half-life periods are evident after chronic estradiol treatment (less than 2 h for the estradiol binder, about 35 h for cytochrome P-450). Depletion of cytoplasmic estradiol binder is not a sufficient condition for mediation of effects on cytochrome P-450 content. Rate of replenishment of microsomal cytochrome P-450 is similar after HCG or estradiol treatment. Both HCG- and estradiol-induced loss of cytochrome P-450 occur not only in Leydig cells but also in microsomes prepared from seminiferous tubules. Additional information is presented contradicting the hypothesis that loss of cytochrome P-450-dependent steroidogenic enzymes caused by HCG could be mediated by estrogens.
比较了对成年雄性大鼠体内单次给予不同剂量人绒毛膜促性腺激素（HCG）以及单次或重复注射雌二醇后，对睾丸细胞质雌二醇结合剂浓度和微粒体孕酮结合细胞色素P - 450的影响。HCG诱导的雌二醇结合剂和细胞色素P - 450浓度丧失的半衰期相同（6小时），而在慢性雌二醇处理后，这些半衰期出现明显分离（雌二醇结合剂少于2小时，细胞色素P - 450约为35小时）。细胞质雌二醇结合剂的耗竭并非介导对细胞色素P - 450含量影响的充分条件。HCG或雌二醇处理后，微粒体细胞色素P - 450的补充速率相似。HCG和雌二醇诱导的细胞色素P - 450丧失不仅发生在睾丸间质细胞中，也发生在由生精小管制备的微粒体中。还提供了其他信息，与HCG引起的细胞色素P - 450依赖性类固醇生成酶丧失可由雌激素介导这一假说相矛盾。
