Vickery B H, Powell J, Stevens V C
Department of Physiology, Syntex Research, Palo Alto, California.
Int J Fertil. 1988 May-Jun;33(3):188-93.
Acute responsiveness in vivo of the baboon corpus luteum to a course of twice daily injections of human chorionic gonadotropin (hCG) has been studied with and without concomitant injections of nafarelin, a potent luteinizing hormone-releasing hormone (LH-RH) agonist. HCG injection alone caused an acute (1 hour) rise in circulating levels of progesterone (P), confirmed to be a direct effect at the luteal level, since no change in circulating levels of endogenous LH was detected. When hCG was coadministered with a low dose of nafarelin (50 micrograms per injection), circulating levels of LH rose, but the rise in serum P levels was blunted. However, when hCG was coadministered with a high dose of nafarelin (250 micrograms per injection), serum LH levels rose only in response to the first injection and serum levels of P were not elevated, suggesting a desensitization of the pituitary to the LH-RH agonist and of the corpus luteum to the hCG. The profile of luteal P during the luteal phase in response to combined treatment with hCG and nafarelin also reflected these effects, being intermediate between vehicle controls and hCG treatment alone. This first demonstration of a luteal desensitization to gonadotropin by an LH-RH agonist in primates may account for previously noted successful interception of pregnancy in baboons treated with these agents.
研究了在有或没有同时注射那法瑞林（一种强效促黄体生成激素释放激素（LH-RH）激动剂）的情况下，狒狒黄体对每天两次注射人绒毛膜促性腺激素（hCG）疗程的体内急性反应。单独注射hCG导致孕酮（P）循环水平急性（1小时）升高，由于未检测到内源性LH循环水平的变化，证实这是黄体水平的直接作用。当hCG与低剂量那法瑞林（每次注射50微克）共同给药时，LH循环水平升高，但血清P水平的升高受到抑制。然而，当hCG与高剂量那法瑞林（每次注射250微克）共同给药时，血清LH水平仅在首次注射时升高，且血清P水平未升高，提示垂体对LH-RH激动剂以及黄体对hCG脱敏。黄体期黄体P对hCG和那法瑞林联合治疗的反应情况也反映了这些作用，处于单独使用载体对照和单独使用hCG治疗之间。灵长类动物中LH-RH激动剂导致黄体对促性腺激素脱敏的这一首次证明，可能解释了先前在用这些药物治疗的狒狒中成功阻断妊娠的现象。
