Hutchison J S, Nelson P B, Zeleznik A J
Endocrinology. 1986 Nov;119(5):1964-71. doi: 10.1210/endo-119-5-1964.
In the nonfertile menstrual cycle, the frequency of episodic LH secretion declines from approximately 1 pulse/h in the early luteal phase to 1 pulse/4-8 h in the mid- to late luteal phase, but the relevance of this phenomenon to the initiation of functional luteal regression is not completely understood. We investigated whether a reduction in LH pulse frequency causes a decline in luteal progesterone production by experimentally reducing LH pulse frequency during the early luteal phase, and measured the effects on the subsequent plasma progesterone pattern and the onset of luteal regression. Rhesus monkeys were rendered anovulatory by placing radiofrequency lesions in the arcuate region of the medial basal hypothalamus or surgically transecting the hypothalamic-pituitary stalk. Endogenous gonadotropin secretion and ovulatory menstrual cycles were restored by pulsatile infusion of synthetic GnRH at a frequency of 1 pulse/h. Commencing on days 3-6 of the luteal phase, GnRH frequency was changed to either 1 pulse/8 h (four animals) or 1 pulse/24 h (four animals), or maintained at the standard 1 pulse/h frequency (four animals). Luteal phases of 13- to 17-day duration were observed in all animals kept on the 1 pulse/h frequency and in three of four animals in which the frequency was changed to 1 pulse/8 h on day 3 of the luteal phase. Daily midluteal phase (days 5-10) plasma progesterone levels observed in response to the 1 pulse/h and 1 pulse/8 h infusion regimens were similar (mean +/- SE, 4.1 +/- 0.4 vs. 3.2 +/- 0.4 ng/ml; P greater than 0.1). In contrast, short luteal phases were observed in all animals after the LH pulse frequency was reduced to 1 pulse/24 h. Comparison of plasma LH responses to a representative GnRH pulse of each GnRH infusion regimen revealed that the maximal LH levels attained in response to 1 pulse/8 h (47.5 +/- 11.5 ng/ml) were significantly greater (P less than 0.05) than the maximal LH levels attained in response to 1 pulse/h (30.5 +/- 3.2 ng/ml) or 1 pulse/24 h (27.2 +/- 5.0 ng/ml). Progesterone levels remained elevated for 140-200 min after the LH pulse resulting from the 1 pulse/8 h infusion regimen. In response to the 1 pulse/24 h infusion regimen, plasma progesterone levels remained elevated for 60 min after the LH pulse.(ABSTRACT TRUNCATED AT 400 WORDS)
在非排卵期的月经周期中，促黄体生成素（LH）脉冲式分泌的频率从黄体期早期的约每小时1次脉冲下降至黄体期中后期的每4 - 8小时1次脉冲，但这种现象与功能性黄体退化起始的相关性尚未完全明确。我们通过在黄体期早期实验性降低LH脉冲频率，研究LH脉冲频率降低是否会导致黄体孕酮分泌减少，并测定其对随后血浆孕酮模式及黄体退化起始的影响。通过在内侧基底下丘脑的弓状区域放置射频损伤或手术切断下丘脑 - 垂体柄，使恒河猴无排卵。通过以每小时1次脉冲的频率脉冲式输注合成促性腺激素释放激素（GnRH）来恢复内源性促性腺激素分泌及排卵性月经周期。从黄体期第3 - 6天开始，将GnRH频率改为每8小时1次脉冲（4只动物）或每24小时1次脉冲（4只动物），或维持在标准的每小时1次脉冲频率（4只动物）。所有维持每小时1次脉冲频率的动物以及在黄体期第3天频率改为每8小时1次脉冲的4只动物中的3只，黄体期持续时间为13 - 17天。在黄体期中期（第5 - 10天）观察到，每小时1次脉冲和每8小时1次脉冲输注方案下的每日血浆孕酮水平相似（平均值±标准误，4.1±0.4对3.2±0.4 ng/ml；P大于0.1）。相比之下，在LH脉冲频率降至每24小时1次脉冲后，所有动物的黄体期均较短。比较每种GnRH输注方案的代表性GnRH脉冲后的血浆LH反应发现，每8小时1次脉冲（47.5±11.5 ng/ml）后的最大LH水平显著高于每小时1次脉冲（30.5±3.2 ng/ml）或每24小时1次脉冲（27.2±5.0 ng/ml）后的最大LH水平（P小于0.05）。每8小时1次脉冲输注方案产生的LH脉冲后，孕酮水平在140 - 200分钟内保持升高。对于每24小时1次脉冲输注方案，LH脉冲后血浆孕酮水平在60分钟内保持升高。（摘要截短至400字）
