BRAIN ANGIOTENSIN RECEPTOR FUNCTION CONTROL AND ANATOMY

脑血管紧张素受体功能控制和解剖学

基本信息

批准号：
2264137
负责人：
Robert Charles Speth
金额：
$ 8.97万
依托单位：
WASHINGTON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1986
资助国家：
美国
起止时间：
1986-07-01 至 1995-09-29
项目状态：
已结题

项目摘要

This project will characterize brain angiotensin H (AII) receptor subtypes. The ultimate goals this project will be to determine the AII receptor subtypes mediating the various functions of AII in the brain. The rationale for these studies derives from recent observations that sulfhydryl reducing agents inhibit binding to one of the brain AII receptor subtypes. Since most studies of brain AII receptor binding have been done in the presence of sulfhydryl reducing agents, only one the of the brain AII receptor subtypes has been studied in detail. The specific aims of this project are to identify agents that act as selective agonists at brain AII receptor subtypes, to pharmacologically characterize the AII receptor subtypes, to determine if additional AII receptor subtypes occur in the brain, to determine the effects of sulfhydryl reactive agents on brain AII receptors, to determine if brain AII receptors couple to G proteins, and to examine functional responses to agonists and antagonists of AII administered directly into the brain. For functional studies, selective antagonists for one subtype will be given prior to the agonist to preclude mediation of the response by that subtype. Angiotensin II acts in the brain primarily to regulate fluid and electrolyte balance, however, it is also thought to have additional functions. The discovery of subtypes of AII receptors in the brain, may indicate that discrete, noncardiovascular functions for AII will be discovered. Since many brain diseases still have unknown etiologies, disturbances in brain angiotensinergic function could play a role in such disorders. The methods to be used in this project are peptide synthesis using FMOC techniques to prepare AII receptor subtype selective of analogs AII, radioligand binding assays, including in vitro receptor autoradiography to determine the AII receptor subtype profile of brain-nuclei. Binding assays will be done in the presence of ligands and conditions selective for individual AII receptor subtypes; and in vivo testing of responses, e.g., dipsogenesis and blood pressure changes, to angiotensins directly administered into the rat brain. The radioligand binding data will be analyzed by nonlinear regression procedures capable of determining and evaluating binding constants for multiple receptor subtypes. In vivo testing procedures will compare the efficacy of AT1, and AT2 receptor subtypes selective AII analogs in the absence and presence of All receptor selective antagonists by Students's t tests.

该项目将表征大脑血管紧张素 H (AII) 受体亚型。该项目的最终目标是确定 AII 受体介导大脑中 AII 各种功能的亚型。这这些研究的基本原理源自最近的观察巯基还原剂抑制与大脑 AII 受体之一的结合亚型。由于大多数关于大脑 AII 受体结合的研究已经完成在存在巯基还原剂的情况下，大脑中只有一个所有受体亚型均已得到详细研究。具体目标该项目旨在鉴定在大脑中充当选择性激动剂的药物 AII 受体亚型，用于表征 AII 受体的药理学特征亚型，以确定是否存在其他 AII 受体亚型大脑，确定巯基反应剂对大脑 AII 的影响受体，以确定大脑 AII 受体是否与 G 蛋白偶联，并检查 AII 激动剂和拮抗剂的功能反应直接注射到大脑中。对于功能研究，选择性一种亚型的拮抗剂将在激动剂之前给予，以防止该亚型对反应的调节。血管紧张素 II 的作用是大脑主要调节液体和电解质平衡，然而，还被认为具有附加功能。 AII亚型的发现大脑中的受体，可能表明离散的、非心血管的 AII 的功能将会被发现。由于许多脑部疾病仍然存在病因不明，大脑血管紧张素能功能紊乱可能在此类疾病中发挥作用。该项目中要使用的方法是使用FMOC技术进行肽合成来制备AII受体亚型选择性类似物 AII、放射性配体结合测定，包括体外受体放射自显影以确定 AII 受体亚型谱脑核。结合测定将在配体存在的情况下进行对个体 AII 受体亚型具有选择性的条件；和体内测试反应，例如体力发生和血压变化，以血管紧张素直接注射到大鼠大脑中。放射性配体结合数据将通过非线性回归程序进行分析，该程序能够确定和评估多个受体的结合常数亚型。体内测试程序将比较 AT1 的功效，以及 AT2 受体亚型选择性 AII 类似物在不存在和存在的情况下所有受体选择性拮抗剂均通过Students's t检验。