Torii R, Nigi H
Institute for Experimental Animals, Shiga University of Medical Science, Japan.
Jikken Dobutsu. 1993 Apr;42(2):143-9. doi: 10.1538/expanim1978.42.2_143.
We investigated the mechanism of reduction of hypothalamo-pituitary-ovarian function in female Japanese monkeys in the non-mating season. We administered PMSG and LH-RH to 19 females in the non-mating and in the mating season. When PMSG was administered every day for 12 to 14 days to seven monkeys in the non-mating season, follicle development was observed together with an increase in serum estradiol-17 beta (E2), but there was no rise in serum LH in two animals and little increase in five others. Follicle involution began about ten days after PMSG administration, and no ovulation occurred. These findings show that secretion of LH by the pituitary in response to positive feedback by the E2 secreted by the follicles which had developed was in adequate to induce ovulation. Serum LH levels increased markedly in five females after a single iv injection of LH-RH in the mating season, but not at all in the non-mating season, even when five-times the dose was administered. These data show that the LH-secreting function of the pituitary is definitely reduced in the non-mating season. When LH-RH was administered to seven monkeys following PMSG administration, an LH surge was observed in all animals, and ovulation occurred in four animals. These findings suggest that one reason for the reduction in pituitary-ovarian function in the non-mating season was a decline in LH-RH secretion by the hypothalamus.
我们研究了非交配季节雌性日本猕猴下丘脑 - 垂体 - 卵巢功能减退的机制。我们在非交配季节和交配季节对19只雌性猕猴给予了孕马血清促性腺激素（PMSG）和促黄体生成素释放激素（LH - RH）。在非交配季节，对7只猕猴连续12至14天每天给予PMSG，观察到卵泡发育，同时血清雌二醇 - 17β（E2）增加，但有2只动物血清LH未升高，另外5只动物升高很少。PMSG给药后约10天卵泡开始退化，未发生排卵。这些结果表明，发育卵泡分泌的E2产生正反馈时，垂体分泌LH不足以诱导排卵。在交配季节，5只雌性猕猴单次静脉注射LH - RH后血清LH水平显著升高，但在非交配季节，即使给予5倍剂量，血清LH水平也完全没有升高。这些数据表明，垂体分泌LH的功能在非交配季节确实减退。在给予PMSG后对7只猕猴给予LH - RH，所有动物均观察到LH峰，4只动物发生排卵。这些结果表明，非交配季节垂体 - 卵巢功能减退的一个原因是下丘脑LH - RH分泌减少。
