BRAIN MONOAMINES AND LUTEINIZING HORMONE SECRETION

本研究项目的总体目标是调查 神经化学机制，卵巢激素，雌二醇（E2）和 孕酮（P），发挥其反馈控制的分泌， 促黄体生成激素（LH）从垂体前叶，和整体 根据研究假设，刺激和抑制作用 卵巢激素对LH分泌的影响是通过 调节， 直接或间接，LH释放激素（LHRH）的神经分泌 正中隆起 此更新应用程序的重点是 肾上腺素能神经递质，去甲肾上腺素（NE） 和肾上腺素（EPI），以及神经肽，包括内源性阿片类药物， 神经肽Y在卵巢激素正反馈调节中的作用 对成年雌性大鼠LHRH和LH分泌的影响，其次，对 在新生儿早期由性腺激素产生， 这些神经递质和神经肽系统对 卵巢激素在成年期 这项建议的具体目标是 首先，为了进一步研究肾上腺素能神经元之间的相互作用， 神经递质与NPY及NPY与LHRH在卵巢激素调节中的相互作用 荷尔蒙正反馈 这些实验将检验 肾上腺素能和神经肽Y系统在诱导LHRH变化中的作用 在卵巢激素之前的正中隆起的浓度- 在介导P对LHRH的刺激作用中的作用 体外释放。 其他研究将调查阿片类药物的作用 和GABA系统调节神经肽Y和肾上腺素能传递控制 LHRH释放，并将进一步表征的机制和 NPY易化LHRH诱导LH的生理意义 从垂体前叶细胞释放。 第二个具体目标是 检查卵巢激素、肾上腺素能、阿片类和/或GABA 系统影响内侧基底膜中NPY前体mRNA的水平 下丘脑 第三组研究将更全面地描述 肾上腺素能肽能对LHRH神经分泌控制的变化 通过早期暴露于E2而使大鼠瘦化，特别是通过测试大鼠是否 在正常女性中诱导LH峰的神经化学前体 卵巢激素或阿片样物质或GABA受体的拮抗剂（即， LHRH和NPY的积累，NE/EPI周转的激活）发生在 雌性化的动物，但不发生在去雌性化的动物，两种性别。 第四个具体目标是调查是否通过 新生儿暴露于E2影响抑制性EOP的发展， GABA能控制肾上腺素能递质和LHRH的释放， 以及新生儿暴露于E2是否与卵巢激素有关 积极的反馈机制。

The overall objective of this research project is to investigate the neurochemical mechanisms by which the ovarian hormones, estradiol (E2) and progesterone (P), exert their feedback controls over the secretion of luteinizing hormone (LH) from the anterior pituitary gland, and the overall hypothesis under investigations that the stimulatory and inhibitory effects of the ovarian hormones on the secretion of LH are mediated by changes in the activity of monoaminergic and peptidergic systems that regulate, directly or indirectly, the neurosecretion of LH-releasing hormone (LHRH) from the median eminence. This renewal application focusses on the interplay between the adrenergic neurotransmitters, norepinephrine (NE) and epinephrine (EPI), and neuropeptides, including endogenous opioids and neuropeptide Y, in mediating aspects of ovarian hormone positive feedback on LHRH and LH secretion in adult female rats, and secondly, on the effects exerted by gonadal hormones during the early neonatal period that influence the responsiveness of these neurotransmitter and neuropeptide systems to ovarian hormones in adulthood. The specific aims of this proposal are first, to further investigate the interactions between the adrenergic neurotransmitters and NPY and between NPY and LHRH in mediating ovarian hormone positive feedback. These experiments will examine the involvement of adrenergic and NPY systems in inducing the changes in LHRH concentrations in the median eminence that precede the ovarian hormone- induced LH surge and in mediating the stimulatory effect of P on LHRH release in vitro. Additional studies will investigate the action of opioid and GABA systems to regulate NPY and adrenergic transmission controlling LHRH release, and will further characterize the mechanisms and the physiological significance of the facilitation by NPY of LHRH-induced LH release from anterior pituitary cells. The second specific aim is to examine whether ovarian hormones, and adrenergic, opioid and/or GABA systems influence the levels of NPY precursor mRNA in the medial basal hypothalamus. The third set of studies will more completely characterize the changes in adrenergic-peptidergic control over LHRH neurosecretion in rats defeminized by early exposure to E2, specifically by testing whether the neurochemical antecedents of the LH surge induced in normal females by ovarian hormones or antagonists at opioid or GABA receptors (i.e., accumulation of LHRH and NPY, activation of NE/EPI turnover) occur in feminized animals, but fail to occur in defeminized animals, of both sexes. The fourth specific aim is to investigate whether defeminization by neonatal exposure to E2 affects the development of the inhibitory EOP and GABAergic controls over the release of adrenergic transmitters and LHRH, and whether neonatal exposure to E2 with respect to ovarian hormone positive feedback mechanisms.