ROLE OF PROGESTERONE RECEPTORS IN FSH SURGES

促性腺激素激增是极其重要的生物事件，依赖于 关于卵巢和神经内分泌的适当细胞整合 信号。原发的促黄体生成素和卵泡刺激素峰值取决于 大脑中的神经和激素(雌激素、黄体酮)刺激，以及 继发性促卵泡激素激增需要卵巢类固醇的协调作用， 垂体促性腺激素中的抑制素和激活素。我们最近得到了 有证据表明对排卵前期和继发性的刺激 促性腺激素激增需要激活孕酮(P)受体 (Prs)，即使在没有循环P.的情况下也是如此。 导致GnRH从下丘脑释放的信号，并 继发性FSH来自垂体，必须在PR水平汇聚在 神经元和促性腺激素。我们假设这些 整合过程依赖于E/2，S诱导PR表达的能力， 以及神经内分泌信号激活这些PR的能力 不依赖配体的方式。具体地说，我们将测试这一想法 神经递质信号可以激活神经元PR，导致刺激 GnRH和初级促性腺激素激增，激活素和P可以 激活PR，有助于释放二次FSH激增。 在目标1中，我们将使用微透析方法来确定 有助于释放二次促卵泡激素激增。在目标1中，我们将使用 微透析法测定激素治疗后促性腺激素释放激素是否激增 卵巢切除(OVX)大鼠用P 拮抗剂，或I.C.V.注射PR反义寡核苷酸治疗卵巢癌 干扰PR的合成。在目标2和目标3中，我们将使用基因转移方法 引入含有黄体酮反应元件的融合基因 (Pre)连接到报告基因，进入体外培养的下丘脑神经元和 活着。我们将使用这种方法来直接确定配体无关 PR的激活发生在中枢神经元，并确定这是否 这一过程与排卵前的浪涌产生过程有关。在……里面 目标4，我们将直接评估公关部门参与调解 激活素对卵泡刺激素分泌的影响激活素刺激物将被提交给 野生型和孕激素来源的垂体前叶细胞培养 受体敲除(PRKO)小鼠和FSH反应将被测量和 比较一下。如果在PRKO来源的培养中注意到反应缺陷， 然后我们将进行基因转移实验，我们将在实验中介绍 将MPR导入PRKO来源的细胞，并确定这些细胞的能力 挽救促卵泡激素对激活素反应性的治疗。在目标5和目标6中，我们将 将Pre-Report融合基因导入垂体前叶细胞 以确定激活素是否能激活PR，以及这是否 这一过程确实与FSH的发情释放有关。这个 从这些研究中获得的信息将对我们的 对整合、细胞和分子事件的理解 包括排卵期涌浪的产生过程。因此，它可能会 对理解不育症有重要的意义 与类固醇反馈和中期激素产生中断有关 周期排卵荷尔蒙激增。更重要的是，这些实验 也可能为细胞机制提供新的见解 整合内分泌和神经信号的功能，从而带来 关于各种生物反应，例如那些涉及 有动机的行为、生殖发育、压力反应或 学习和记忆。

Gonadotropin surges are critically important biological events that depend upon the appropriate cellular integration of ovarian and neuroendocrine signals. Primary LH and FSH surges are dependent upon integration of neural and hormonal (estrogen, progesterone) stimuli in the brain, and secondary FSH surges require coordinated actions of ovarian steroids, inhibin, and activin in pituitary gonadotropes. We recently obtained evidence that stimulation of both the preovulatory and secondary gonadotropin surges requires activation of progesterone (P) receptors (PRs), even in the absence of circulating P. We have thus proposed that signals leading to release of GnRH surges from hypothalamus, and to secondary FSH surges from pituitary, must converge at the level of PR in neurons and gonadotropes, respectively. We hypothesize that these integrative processes depend upon E/2,s capacity to induce PR expression, and the ability of neuroendocrine signals to activate these PRs in a ligand-independent manner. Specifically, we will test the idea that neurotransmitter signals can activate neuronal PRs, leading to stimulation of GnRH and primary gonadotropin surges, and that activin and P can activate PRs, contributing to release to release of secondary FSH surges. In Aim 1, we will use a microdialysis approach to determine if contributing to release of secondary FSH surges. In Aim 1, we will use a microdialysis approach to determine if GnRH surges in steroid-treated ovariectomized (OVX) rats are blocked by pretreatment with P antagonists,or i.c.v. infusions of PR antisense oligonucleotides to disrupt PR synthesis. In Aims 2 and 3, we will use a gene transfer method to introduce a fusion gene containing a progesterone response element (PRE) linked to a reporter gene, into hypothalamic neurons in vitro and in vivo. We will use this approach to directly determine ligand-independent activation of PRs occurs in central neurons, and ascertain whether this process is associated with the preovulatory surge-generating process. In Aim 4, we will directly assess the involvement of the PR in mediating the effects of activin on FSH secretion. Activin stimuli will be presented to anterior pituitary cell cultures derived from wild-type and progesterone receptor knock-out (PRKO) mice, and FSH responses will be measured and compared. If a response deficit is noted in the PRKO-derived cultures, then we will conduct gene transfer experiments in which we will introduce the mPR into PRKO-derived cells, and determine the ability of these treatments to rescue FSH responsiveness to activin. In Aims 5 & 6, we will transfer the PRE-reporter fusion gene into anterior pituitary cells both in vitro and in vivo to determine if activin can activate PRs, and if this process is indeed associated with the estrous release of FSH. The information gained in these studies will be of major significance in our understanding of the integrative, cellular, and molecular events that comprise the periovulatory surge-generating process. As such, it could have important implications for the understanding of infertilities associated with disruptions of steroid feedback and production of mid- cycle ovulatory hormone surges. Of broader significance, these experiments may also may also provide new insights into the cellular mechanisms which function to integrate endocrine and neural signals, and thereby bring about a variety of biological responses, such as those involved in motivated behaviors, reproductive development, stress responses, or learning and memory.