ROLE FOR HYPOTHALAMIC ADRENERGIC RECEPTORS IN PREOVULATORY LH SURGE

性交引起下丘脑去甲肾上腺素(NE)的增加 排卵前几分钟出现的分泌物 促性腺激素释放激素(GnRH)/黄体生成素激增 (Lh)。去甲肾上腺素与促性腺激素释放激素/促黄体生成素的因果关系 在性交过程中，我们试图阻断性交诱导的 下丘脑(Ih)注射肾上腺素能激动剂引起的GnRH/LH峰 受体阻滞剂，哌唑嗪。对完好的雌性兔进行 推拉灌流7h，连续采集样品10分钟 用于灌流促性腺激素释放激素和血液促黄体生成素。与雄性交配 合作伙伴出现在第三小时，连续注射哌唑嗪 在2小时到7小时之间。目前的数据显示 哌唑嗪处理组性交诱导的GnRH/LH释放减少 女性与对照组比较。然而，哌唑嗪 并未完全取消性交对GnRH/LH的反应。对这件事 最后，至少可以提供三种解释：(1)网元不是 只有决定性交诱导的GnRH/LH峰的因素，(2)去甲肾上腺素可能 也可通过位于脑区外的肾上腺素能受体刺激促性腺激素释放激素 (3)哌唑嗪的剂量可定为 不足以阻断内侧基底区的所有肾上腺素能受体 下丘脑。我们将继续探讨这些问题。归根结底， 这些发现将有助于理解生育和生殖期间的大脑功能 不育的生殖阶段。

Coitus induces an increase in hypothalamic norepinephrine (NE) secretion that occurs several minutes prior to a preovulatory-like surge of gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH). To assess the causal relationship between NE and GnRH/LH release during coitus, we attempted to block the coitus-induced GnRH/LH surge by intrahypothalamic (ih) infusion of an `-adrenergic receptor blocker, prazosin. Intact female rabbits were subjected to push-pull perfusion for 7 h with continuous 10-min sample collections for perfusate GnRH and blood LH measurements. Mating with male partners occurred at the third hour and continuous ih prazosin was given between hours 2 and 7. Present data show that the magnitude of the coitus-induced GnRH/LH release was lower in prazosin-treated females as compared to that in the control group. However, prazosin did not completely abolish the GnRH/LH response to coitus. To this end, at least three interpretations can be offered (1) NE is not the only factor determining the coitus-induced GnRH/LH surge, (2) NE may also stimulate GnRH via `-adrenergic receptors located outside the mediobasal hypothalamus, and (3) the dosage of prazosin may be insufficient to block all `-adrenergic receptors within the mediobasal hypothalamus. We continue to explore these issues. Ultimately, the findings will aid understanding of brain functions during fertile and infertile reproductive stages.