NEURAL REGULATION OF FSH--GNRH RELEASE AND FEEDBACK MECHANISMS

FSH的释放可能受脉动放电的控制。 一种或多种释放因子进入下丘脑- 垂体门静脉系统，也通过内分泌反馈 性腺起源的机制。目前还不知道是否相同 调节促黄体生成素分泌的下丘脑释放因子 十肽GnRH-也控制脉动性分泌 FSH，或者如果一个不同的FSH释放因子发挥主导作用 下丘脑对FSH释放的控制。同样， 促性腺激素释放激素系统参与选择性内分泌反馈 促性腺激素释放的调节尚不清楚。在建议的 实验，新的活体技术，如下丘脑推动- 拉动灌流、垂体微透析和促性腺激素释放激素放射性配体 受体分析将被用来识别这些基本的下丘脑- 垂体腺和性腺的关系。促性腺激素释放激素在 FSH脉冲对雄性大鼠的刺激将首先得到澄清 同步测定下丘脑GnRH释放 外周推拉式灌流液(或垂体透析液)和FSH 血浆。促性腺激素释放激素脉冲频率在选育中的重要性 卵泡刺激素分泌的调节将通过脉搏波确定 不同频率注射促性腺激素释放激素对去垂体大鼠的影响 进行脑下垂体移植。在第二项研究中，分析了 性腺激素对GnRH和FSH分泌的反馈 承担了。GnRH和GnRH的同时测量 促性腺激素释放将在去势的大鼠身上进行 在对照组或睾丸素治疗后确定是否有 去势和类固醇诱导的FSH分泌变化是 与GnRH释放的变化有关。生理学 任何观察到的去势或类固醇诱导的意义 将评估大鼠内源性GnRH释放的变化 进行垂体移植；内源性GnRH模式将 模拟外源性GnRH输注和FSH分泌 将监测对去势和类固醇治疗的反应。 在第三个研究中，负反馈的位置和机制 性腺激素卵泡抑素对卵泡刺激素分泌的影响 将被确定；GnRH和FSH释放将在 完整和去势雄性大鼠全身或全身或手术后 下丘脑内注射猪卵泡液。 促性腺激素对促性腺激素释放激素敏感性的电位反馈调节 和/或促性腺激素释放激素受体水平也将由卵泡抑素 检查过了。这些研究将提供大量新的 关于卵泡刺激素的基本生理控制信息 由几种重要的神经内分泌机制分泌。

The release of FSH is likely controlled by the pulsatile discharge of one or more releasing factors into the hypothalamic- hypophysial portal vessel systems, and also by endocrine feedback mechanisms of gonadal origin. It is not known if the same hypothalamic releasing factor that regulates the secretion of LH - the decapeptide GnRH - also controls the pulsatile secretion of FSH, or if a distinct FSH-releasing factor exerts predominant hypothalamic control over FSH release. Likewise, the involvement of GnRH systems in the selective endocrine feedback regulation of gonadotropin release is unknown. In the proposed experiments, new in vivo techniques such as hypothalamic push- pull perfusion, pituitary microdialysis, and GnRH radioligand receptor assays will be used to discern these basic hypothalamic- hypophysial-gonadal relationships. The role of GnRH release in the stimulation of FSH pulses in male rats will first be clarified by simultaneous measurement of GnRH release in hypothalamic push-pull perfusates (or pituitary dialysates) and FSH In peripheral plasma. The importance of GnRH pulse frequency in the selective regulation of FSH secretion will be determined using pulsatile GnRH infusions of varying frequency in hypophysectomized rats bearing pituitary transplants. In a second study, an analysis of gonadal steroid feedback on GnRH and FSH secretion will be undertaken. Simultaneous measurements of GnRH and gonadotropin release will be carried out in castrated rats following control or testosterone treatment to determine if post- castration and steroid-induced changes in FSH secretion are associated with alterations in GnRH release. The physiological significance of any observed castration- or steroid-induced changes in endogenous GnRH release will be assessed in rats bearing pituitary transplants; endogenous GnRH patterns will be mimicked with exogenous GnRH Infusions, and FSH secretory responses to castration and steroid treatment will be monitored. In a third study the locus and mechanism of the negative feedback actions of the gonadal peptide folliculostatin on FSH secretion will be determined; GnRH and FSH release will be measured in intact and castrated male rats before and after the systemic or intrahypothalamic administration of porcine follicular fluid. Potential feedback regulation of gonadotropin sensitivity to GnRH and/or GnRH receptor levels by folliculostatin will also be examined. These studies will provide a substantial amount of new information regarding the basic physiological control of FSH secretion by several important neuroendocrine mechanisms.