PROLACTIN--HYPOTHALAMIC-GONADAL-AUTOCRINE INTERACTIONS

催乳素是一种极大地影响生育和哺乳的激素。 因此，它在创造和创造中都扮演着至关重要的角色 养育后代。此外，催乳素还起到了更为微妙的作用 在许多组织的功能中发挥作用，如免疫系统， 肝脏和内分泌胰腺，它们需要调整以适应 怀孕和哺乳。因此，它对我们来说是极其重要的 为了了解催乳素的总水平是如何在 不同的繁殖阶段和更进一步，因为尚不清楚 催乳素是一个家族分子，它的组成是如何分泌的 催乳素可能会发生变化。对催乳素分泌的主要影响是 下丘脑/垂体后叶、自分泌/旁分泌和性腺。在……里面 本项目建议：1)进一步研究自分泌抑制作用 分离的催乳素分泌，以及2)如何整合这一过程的研究 由下丘脑和性腺控制。对于后者，我们将 确定下丘脑的一个主要因素--多巴胺和 主要性腺激素、雌激素、自分泌反馈系统。在……里面 对此，我们假设多巴胺对分泌的抑制是 而雌激素对分泌物的刺激作用是通过 自分泌机制的调整。此外，因为独裁者 调节是通过改变磷酸化状态来完成的 分泌的形式，我们将在这个过程中确定多巴胺和 雌激素影响分泌的催乳素的组成。在学习的时候 自分泌系统的分离，制剂的剂量-反应曲线 非磷酸化和磷酸化催乳素与生理学 它们的组合将允许我们确定什么设置(比例 分泌的非磷酸化到磷酸化的催乳素) 与显著的自分泌控制相一致，因此我们可以预测， 根据我们在体内的分析，当这种机制最重要和 当其他控制因素必须占主导地位的时候。对于这些剂量反应 在研究中，我们将使用GH3细胞和原代大鼠垂体细胞进行培养。 在分析了天然的磷酸化位点后， 用于这些研究的催乳素将在体外从重组人 大鼠催乳素。多巴胺和雌激素的影响将在#年进行评估 对原代培养和多巴胺激动剂的影响， 溴隐亭和拮抗剂氟哌啶醇将使用 结合体内、体外实验方法。

Prolactin is a hormone which dramatically affects fertility and lactation and which therefore plays a crucial role in both the creation and nurturing of offspring. In addition, prolactin also plays a more subtle role in the functioning of many tissues such as the immune system, the liver and the endocrine pancreas, which need to adjust to the demands of pregnancy and lactation. It is therefore of immense importance for us to understand how total levels of prolactin are regulated at the different stages of reproduction and further, because there is not known to be a family of prolactin molecules, how the composition of secreted prolactin may change. The primary influences on prolactin secretion are hypothalamic/posterior pituitary, autocrine/paracrine, and gonadal. In this project we propose 1) further study of autocrine inhibition of prolactin secretion in isolation, and 2) a study of how this integrates with controls from the hypothalamus and gonads. For the latter we will determine the affects of a major hypothalamic factor, dopamine, and a major gonadal hormone, estrogen, ont he autocrine feedback system. In this regard, we hypothesize that dopamine inhibition of secretion is independent of, whereas estrogen stimulation of secretion works through, adjustments in the autocrine mechanism. Also, because autocrine adjustments are accomplished via shifts in the phosphorylation state of the forms secreted, we will in the process determine whether dopamine and estrogen affect the composition of secreted prolactin. When studying the autocrine system in isolation, dose-response curves to preparations of non-phosphorylated and phosphorylated prolactin and physiological combinations thereof will allow us to determine what settings (proportion of non-phosphorylated to phosphorylated prolactin secreted) are consistent with significant autocrine control so that we may predict, based on our in vivo analyses, when this mechanism is most important and when other controlling factors must predominate. For these dose response studies we will use GH3 cells and primary rat pituitary cells in culture. After analysis of the natural phosphorylation sites, phosphorylated prolactin for these studies will be produced in vitro from recombinant rat prolactin. The effects of dopamine and estrogen will be assessed in vitro on primary cultures and the effects of a dopamine agonist, bromocryptine, and an antagonist, haloperidol, will be assessed using a combined in vivo in vitro approach.