REGULATION OF PROLACTIN SECRETION AT THE LACTOTROPH

催乳素(PRL)是一种起源于前角细胞的激素。 脑下垂体、乳汁滋养细胞，并在 所有的哺乳动物。它不仅能促进所有哺乳动物的哺乳，而且 也在母亲的行为、怀孕的维持方面发挥作用 作为渗透调节和免疫反应。多巴胺(DA)是一口井 建立了催乳素分泌的生理抑制剂。它起源于 细胞，神经元，在大脑的一个专门区域，下丘脑， 它发送的投射终止于连接 下丘脑和脑下垂体。最近有研究表明，DA 也是催乳素分泌的生理刺激物。从长远来看 本申请的目的是描述DA 对催乳素的分泌有相反的生理作用。使用以下测量方法 PRL分泌以及细胞内转导事件，特异性 该项目的目标将是：(1)确定 催乳素负责刺激催乳素的分泌，(2)确定 哪些G蛋白与PRL的刺激和抑制有关 DA的分泌，(3)确定细胞内的脂质是否参与了 多巴胺对催乳素分泌的刺激作用及(4) 多巴胺刺激催乳素分泌的钙离子。由于PRL有如此多的多个 在生物体生理学中的多方面作用，它对 涉及催乳素的疾病的可能治疗方法的目的 其生理调控的方方面面都被阐明。例如，两者 有关乳腺良恶性疾病的讨论可通过 操纵脑下垂体催乳素的分泌。全面了解如何控制 PRL的分泌将允许其他方法在疾病中操纵它 各州。

Prolactin (pRL) is a hormone which originates in cells of the anterior pituitary gland, lactotrophs, and plays multiple physiological roles in all mammals. Not only does it promote lactation in all mammals, but it also plays a role in maternal behavior, maintenance of pregnancy as well as osmoregulation and the immune response. Dopamine (DA) is a well established physiological inhibitor of PRL secretion. It originates in cells, neurons, within a specialized area of the brain, the hypothalamus, which sends projections that terminate upon the vasculature connecting the hypothalamus with the pituitary gland. It has recently been shown that DA is also a physiological stimulator of PRL secretion. The long term objective of this application is to characterize the mechanism whereby DA has opposing physiological effects on PRL secretion. Using measurements of PRL secretion as well as intracellular transduction events, the Specific Aims of this project will be to: (1) determine which DA receptors on the lactotroph are responsible for stimulation of PRL secretion, (2) determine which G-proteins are linked to stimulation versus inhibition of PRL secretion by DA, (3) determine if the intracellular lipids are involved in the stimulation of PRL secretion by DA and (4) determine the role of calcium in DA-stimulated PRL secretion. Since PRL has so many multi- faceted roles in the physiology of the organism, it is critical for purposes of possible therapeutic approaches to diseases involving PRL that all aspects of its physiological control be clarified. For example, both benign and malignant diseases of the mammary gland are approached by manipulating pituitary PRL secretion. Thorough knowledge of the control of PRL secretion will allow other approaches to its manipulation in disease states.