Mahesh V B
Neurosci Biobehav Rev. 1985 Summer;9(2):245-60. doi: 10.1016/0149-7634(85)90049-1.
The interrelationship between steroid hormone secretion and gonadotropin secretion during the human menstrual cycle is a set of complex interactions. The temporal relationship between estradiol and progesterone secretion, the preovulatory surge of gonadotropins and the time of ovulation, has been studied extensively. The median time interval between the first rise of estradiol, progesterone, LH and FSH, and ovulation has been estimated to be 82.5 hr, 7.8 hr, 32 hr and 21.1 hr, respectively. The median time interval between peak blood concentrations of estradiol, LH and FSH, and the time of ovulation is estimated to be 24, 16.5 and 15.3 hr. There is considerable individual variation in the above mentioned estimates. The rising levels of blood estradiol that are secreted by the maturing ovarian follicles appear to be the primary trigger for the surge of gonadotropins leading to ovulation. In the experimental animal, the estrogen effect takes place at the level of the hypothalamus in the release of LHRH and at the level of the pituitary in increasing its sensitivity to LHRH. There appears to be a good correlation between the nuclear translocation of occupied estrogen receptors in the hypothalamus and the pituitary and the manifestation of estrogen effects. In the human, a rise in progesterone begins to take place after the first rise in LH has occurred. Progesterone appears to have both a stimulatory and inhibitory effect on gonadotropin secretion in the experimental animal and the human. Thus it exerts a fine-tune modulatory influence of estrogen effects which include enhancement of the estradiol induced gonadotropin surge, and perhaps the initiation of the midcycle FSH surge in the human. The abrupt termination of the preovulatory gonadotropin surge is difficult to explain because the pituitary gland is not depleted of its gonadotropin content or its capacity to secrete gonadotropins. Preliminary results suggests that progesterone by exerting its inhibitory influence may be responsible for the termination of the gonadotropin surge. This hypothesis, however, needs careful confirmation. The effects of progesterone may be manifested at higher brain centers, the hypothalamus and the pituitary, and may involve not only the release of LHRH but also an alteration of the pulsatile pattern of release of LHRH. The recognition of these components, along with the presence and control of LHRH degrading enzymes in the hypothalamus and the pituitary, emphasize the complexity of the system and the need for further work to gain a better understanding of the steroidal regulation of gonadotropin secretion.
人类月经周期中甾体激素分泌与促性腺激素分泌之间的相互关系是一系列复杂的相互作用。雌二醇和孕酮分泌之间的时间关系、促性腺激素的排卵前高峰以及排卵时间，都已得到广泛研究。据估计，雌二醇、孕酮、促黄体生成素（LH）和促卵泡生成素（FSH）首次升高与排卵之间的中位时间间隔分别为82.5小时、7.8小时、32小时和21.1小时。雌二醇、LH和FSH血药浓度峰值与排卵时间之间的中位时间间隔估计为24小时、16.5小时和15.3小时。上述估计存在相当大的个体差异。成熟卵巢卵泡分泌的血雌二醇水平升高似乎是导致排卵的促性腺激素高峰的主要触发因素。在实验动物中，雌激素作用发生在下丘脑释放促性腺激素释放激素（LHRH）的水平以及垂体增加其对LHRH敏感性的水平。下丘脑和垂体中被占据的雌激素受体的核转位与雌激素作用的表现之间似乎存在良好的相关性。在人类中，孕酮升高在LH首次升高后开始出现。孕酮在实验动物和人类中似乎对促性腺激素分泌既有刺激作用又有抑制作用。因此，它对雌激素作用发挥微调调节影响，包括增强雌二醇诱导的促性腺激素高峰，也许还包括引发人类月经周期中期的FSH高峰。排卵前促性腺激素高峰的突然终止难以解释，因为垂体并未耗尽其促性腺激素含量或其分泌促性腺激素的能力。初步结果表明，孕酮通过发挥其抑制作用可能是促性腺激素高峰终止的原因。然而，这一假设需要仔细证实。孕酮的作用可能表现在更高的脑中枢、下丘脑和垂体，可能不仅涉及LHRH的释放，还涉及LHRH释放脉冲模式的改变。认识到这些因素，以及下丘脑和垂体中LHRH降解酶的存在和控制，强调了该系统的复杂性以及进一步开展工作以更好地理解促性腺激素分泌的甾体调节的必要性。
