UNEXPECTED RESPONSES OF THE HYPOTHALAMIC GONADOTROPIN-RELEASING-HORMONE PULSE-GENERATOR TO PHYSIOLOGICAL ESTRADIOL INPUTS IN THE ABSENCE OF THE OVARY
UNEXPECTED RESPONSES OF THE HYPOTHALAMIC GONADOTROPIN-RELEASING-HORMONE PULSE-GENERATOR TO PHYSIOLOGICAL ESTRADIOL INPUTS IN THE ABSENCE OF THE OVARY
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DOI：
10.1073/pnas.84.23.8745
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发表时间：
1987-12-01
影响因子：
11.1
通讯作者：
KNOBIL, E
中科院分区：
文献类型：
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作者：
KESNER, JS;WILSON, RC;KNOBIL, E
在恒河猴（Macaca mulatta）中，面对外周循环中广泛变化的雌二醇（E2）水平，脉冲式促性腺激素释放的频率相对恒定-例如，在月经周期的卵泡期和卵巢切除术后。这表明这种类固醇对下丘脑促性腺激素释放激素（GnRH）“脉冲发生器”的调节并不具有重要的生理意义。本文描述了在卵巢切除的猴子中通过生理水平的外源性E2对该脉冲发生器的电活动的意外抑制或完全阻断。这种抑制作用在开始E2输注后2-4.5小时开始，并在皮下植入含E2胶囊后1 - 3周观察到。脉冲发生器的活动也被逮捕的开始和随后的发展过程中雌激素诱导的促黄体激素激增。我们建议，这种抑制下丘脑GnRH脉冲发生器活性的E2在卵巢切除的猴子反映了卵巢的情况下，通常保护这个神经元系统的抑制作用的雌激素在月经周期中的因素。
In the rhesus monkey (Macaca mulatta), the frequency of pulsatile gonadotropic hormone release is relatively constant in the face of widely varying levels of estradiol (E2) in the peripheral circulation-e.g., in the course of the follicular phase of the menstrual cycle and after ovariectomy. This suggests that modulation of the hypothalamic gonadotropin-releasing hormone (GnRH) "pulse generator" by this steroid is not of major physiological importance. Herein is described the unexpected inhibition or total blockade of the electrical activity of this pulse generator in ovariectomized monkeys by physiological levels of exogenous E2. This inhibition began 2-4.5 hr after the initiation of E2 infusion and was noted 1 to 3 weeks after subcutaneous implantation of E2-containing capsules. Pulse generator activity was also arrested during the initiation and subsequent development of estrogen-induced surges of luteinizing hormone. We propose that this inhibition of hypothalamic GnRH pulse generator activity by E2 in ovariectomized monkeys reflects the absence of an ovarian factor that normally protects this neuronal system from the inhibitory action of estrogen during the menstrual cycle.