Neurochemical Correlates of Prolactin Secretion

Badura 9603780催乳素是一种由脑下垂体分泌的蛋白质激素，参与调节哺乳动物的多种生理和行为状态，包括哺乳、动情周期、母体行为和免疫系统功能。虽然催乳素清楚地参与了许多不同的生理过程，但其确切的作用机制以及在不同条件下控制催乳素分泌的方式尚不清楚。主要的方法是研究各种因素如何影响应激、哺乳或发情周期中发生的催乳素激增。问题是，催乳素的激增涉及多个系统的激活，因此，这种方法的结果可能很难解释。巴杜拉博士试图通过检测一年中波动的基础催乳素水平的变化，来加强我们对个体调节系统对催乳素反应的作用的理解。她利用了这样一个事实，即催乳素表现出明显的年度波动，与光周期的变化相对应，最有可能的是日长。事实上，巴杜拉博士已经证明，非刺激性的日照时间会导致循环中的催乳素自然下降。使用这个模型，她将描述下丘脑室旁核内的神经递质的特征，下丘脑室旁核是调节垂体功能的主要神经内分泌脑区。使用体内微透析和高效液相色谱-电化学法，巴杜拉博士将把神经递质的释放和代谢与不同光周期条件下基础催乳素释放的变化联系起来。她还将使用这个模型和方案来解开性腺类固醇激素对男性和女性这一系统的一些潜在影响。此外，巴杜拉博士还将研究这些调节因素在不同环境条件下如何直接影响脑下垂体功能。这些研究的结果将为我们理解神经内分泌过程提供新的知识。剖析催乳素调节明显无关的生理系统的机制将有助于我们更好地理解具有多个靶点和功能的进化激素系统的适应意义。

Badura 9603780 Prolactin, a protein hormone secreted by the anterior pituitary gland, is involved in modulating a large variety of physiological and behavioral states in mammals, including lactation, estrous cyclicity, maternal behavior, and immune system function. While prolactin is clearly involved in many different physiological processes, the precise mechanism of action and the ways in which prolactin secretion is controlled under various conditions is not well understood. The primary approach has been to examine how various factors affect the surges of prolactin that occur during stress, lactation, or during the estrous cycle. The problem is that surges of prolactin involve the activation of multiple systems and, therefore, the results from this approach can be very difficult to interpret. Dr. Badura seeks to enhance our understanding of the role of individual modulatory systems to the prolactin response by examining changes in basal prolactin levels that fluctuate throughout the year. She is taking advantage of the fact that prolactin shows a marked annual fluctuation that corresponds with changes in photoperiod, most likely daylength. Indeed Dr. Badura has demonstrated that nonstimulatory daylengths will induce naturally occurring declines in circulating prolactin. Using this model, she will characterize the neurotransmitters within the paraventricular nucleus of the hypothalamus, a major neuroendocrine brain region that regulates pituitary function. Using in vivo microdialysis and HPLC-EC techniques, Dr. Badura will correlate the release and metabolism of neurotransmitters with alterations that are seen in basal prolactin release under different photoperiod conditions. She will also use this model and protocol to untangle some of the potential effects of gonadal steroid hormones on this system in both males and females. In addition, Dr. Badura will examine how these regulatory factors influence pituitary function directly under different environmental conditions. The results from these studies will provide new knowledge in our understanding of neuroendocrine processes. Dissecting the mechanisms by which prolactin regulates apparently unrelated physiological systems will enhance our understanding of the adaptive significance of evolving hormonal systems that possess multiple targets and function.