Van Vugt D A, Lam N Y, Ferin M
Endocrinology. 1984 Sep;115(3):1095-101. doi: 10.1210/endo-115-3-1095.
Pulsatile secretion of LH in women has been shown to vary during the menstrual cycle. LH pulse frequency during the luteal phase is markedly reduced compared to that in the follicular phase. The objectives of the present study were to determine if similar changes in pulsatile LH secretion occur in the monkey, and whether endogenous opiates are involved in producing these changes. In order to document if LH pulse frequency is reduced in the nonhuman primate luteal phase, serial blood samples were collected from 10 rhesus monkeys at 15-min intervals for 6 h at 3 different times of the luteal phase (early, mid-, and late). This pattern of secretion was contrasted to that observed during the ensuing early follicular phase. LH pulse frequency during the luteal phase was significantly reduced compared to the early follicular phase. Mean pulse frequency (+/- SE) was 0.84 +/- 0.16 pulses/6 h in the luteal phase vs. 2.99 +/- 0.58 pulses/6 h in the early follicular phase. When endogenous opioid activity was blocked during the luteal phase by a 5-h continuous infusion of naloxone (2 mg/h), an opiate antagonist, LH pulse frequency was increased to 2.48 +/- 0.25 pulses/5 h. This frequency was markedly different from the frequency of 0.85 +/- 0.17 pulses/5 h observed in the control period which immediately preceeded the naloxone infusion. The mean amplitude of the LH pulses in the luteal phase, which was significantly greater than that observed in the early follicular phase (20.9 +/- 1.9 ng/ml and 11.7 +/- 0.3 ng/ml) was not affected by naloxone (23.5 +/- 2.4 ng/ml vs. 25.3 +/- 1.9 ng/ml). Infusion of naloxone for longer periods (9 h) in 3 additional monkeys caused an increase in LH pulse frequency which was maintained in 2 of the monkeys, whereas the third animal exhibited only an acute response (a single pulse). These results indicate that the reduction in LH pulse frequency that occurs in the luteal phase of the rhesus menstrual cycle is an event in which endogenous opiates participate. Our previous finding that beta-endorphin release from neurons in the median eminence is stimulated during the luteal phase of the monkey, together with the present results, suggest that beta-endorphin functions as a modulator of pulsatile LH secretion in the primate menstrual cycle.
女性促黄体生成素（LH）的脉冲式分泌在月经周期中会发生变化。与卵泡期相比，黄体期的LH脉冲频率明显降低。本研究的目的是确定猕猴是否也会出现类似的LH脉冲式分泌变化，以及内源性阿片类物质是否参与了这些变化的产生。为了记录非人灵长类动物黄体期LH脉冲频率是否降低，在黄体期的3个不同时间点（早期、中期和晚期），每隔15分钟从10只恒河猴采集一次系列血样，持续6小时。将这种分泌模式与随后的卵泡早期观察到的模式进行对比。与卵泡早期相比，黄体期的LH脉冲频率显著降低。黄体期的平均脉冲频率（±标准误）为0.84±0.16次脉冲/6小时，而卵泡早期为2.99±0.58次脉冲/6小时。当在黄体期通过连续5小时输注阿片拮抗剂纳洛酮（2毫克/小时）阻断内源性阿片类物质活性时，LH脉冲频率增加到2.48±0.25次脉冲/5小时。这个频率与纳洛酮输注前紧接着的对照期观察到的0.85±0.17次脉冲/5小时的频率明显不同。黄体期LH脉冲的平均幅度明显大于卵泡早期（分别为20.9±1.9纳克/毫升和11.7±0.3纳克/毫升），但不受纳洛酮影响（分别为23.5±2.4纳克/毫升和25.3±1.9纳克/毫升）。在另外3只猴子中延长纳洛酮输注时间（9小时）导致LH脉冲频率增加，其中2只猴子的增加得以维持，而第三只动物仅表现出急性反应（单次脉冲）。这些结果表明，恒河猴月经周期黄体期出现的LH脉冲频率降低是内源性阿片类物质参与的一个过程。我们之前的发现是，猕猴黄体期时，正中隆起神经元释放β-内啡肽会受到刺激，结合目前的结果，表明β-内啡肽在灵长类动物月经周期中作为LH脉冲式分泌的调节剂发挥作用。
