Zeleznik A J
Departments of Cell Biology and Physiology and Obstetrics, Gynecology and Reproductive Sciences, The University of Pittsburgh School of Medicine and the Magee-Women's Research Institute, Pittsburgh, PA 15213, USA. zeleznik+@pitt.edu
Proc Natl Acad Sci U S A. 1998 Sep 1;95(18):11002-7. doi: 10.1073/pnas.95.18.11002.
Although it is well established that the secretory activity of the corpus luteum absolutely depends on the presence of pituitary-derived luteinizing hormone (LH), it is unknown why the life span of the corpus luteum is extended during early pregnancy by the placental production of chorionic gonadotropin (CG) but regresses in the presence of LH despite the fact that CG and LH have similar actions on the corpus luteum. To compare the responses of the corpus luteum to LH and human CG (hCG), cynomolgus monkeys whose endogenous gonadotropin secretion was blocked during the luteal phase of the menstrual cycle with a gonadotropin-releasing hormone antagonist were i.v. infused with either LH or CG. Infusion of LH at a constant rate overcame the gonadotropin-releasing hormone antagonist-mediated premature luteal regression but failed to prolong the functional life span of the corpus luteum. Continuous infusions of hCG did not effect a pregnancy-like pattern of gonadotropin secretion, but the functional life span of the corpus luteun was extended in two of three animals. Infusion of either LH or hCG in an exponentially increasing manner prolonged the functional life span of the corpus luteum beyond its normal duration. These results indicate that luteal regression at the termination of nonfertile menstrual cycles is caused by a large reduction in the responsiveness of the aging corpus luteum to LH, which can be overcome by elevated concentrations of either LH or CG.
尽管黄体的分泌活动绝对依赖于垂体来源的促黄体生成素（LH）这一点已得到充分证实，但尚不清楚为何在妊娠早期，胎盘产生的绒毛膜促性腺激素（CG）能延长黄体寿命，而在LH存在的情况下黄体却会退化，尽管CG和LH对黄体有相似作用。为比较黄体对LH和人绒毛膜促性腺激素（hCG）的反应，在月经周期黄体期用促性腺激素释放激素拮抗剂阻断内源性促性腺激素分泌的食蟹猴，经静脉输注LH或CG。以恒定速率输注LH可克服促性腺激素释放激素拮抗剂介导的黄体过早退化，但未能延长黄体的功能寿命。持续输注hCG并未产生类似妊娠的促性腺激素分泌模式，但三只动物中有两只的黄体功能寿命得以延长。以指数递增方式输注LH或hCG可使黄体的功能寿命延长至超过正常时长。这些结果表明，非生育月经周期结束时的黄体退化是由于衰老的黄体对LH的反应性大幅降低所致，而LH或CG浓度升高可克服这一情况。
