BRAIN ANGIOTENSIN II RECEPTOR IN HYPERTENSION

高血压脑血管紧张素 II 受体

• 批准号: 2223046
• 负责人: KATHLEEN HELEN BERECEK
• 金额: $ 21.5万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2223046
• 关键词: angiotensin /renin /aldosterone hypertension; angiotensin II; antihypertensive agents; captopril; chemical binding; disease /disorder model; genetic models; hormone receptor; hormone regulation /control mechanism; hypothalamus; laboratory rat; neurochemistry; norepinephrine; tissue /cell culture; vascular smooth muscle

The long-term goals of this proposal are to study angiotensin II (AII) receptor regulation in primary neuronal enriched (PNC) and vascular smooth muscle cell (VSMC) cultures from SHR, WKY and Sprague-Dawley (SD) rats, to examine the effects of captopril and other converting enzyme inhibitors (CEI) on AII receptor regulation in these rats and to determine whether the anti-hypertensive effect of CEI in SHR is related to a down-regulation of brain AII receptors. We will utilize PNC and VSMC cultures from neonates to compare AII receptor regulation in SHR vs normotensive rats and to determine the effects of CEI on central and peripheral AII receptors. This project is divided into two specific aims. Specific Aim 1: To test the hypothesis that brain AII receptors are biochemically and functionally different in SHR vs normotensive rat strains and that brain AII receptors in SHR are regulated differently from those of WKY and SD rats. We will utilize radioligand binding techniques to characterize AII receptor number and affinity in PNC (hypothalamus/brain stem co-cultures) from SHR, WKY and SD pups and compare these to AII receptors in VSMC cultured from the same pups. Binding studies will be performed in intact cells and in membranes prepared from these cells. We will incubate cells with agents known to stimulate or decrease AII binding and determine whether there are differences in the responses of AII receptors in SHR vs WKY and in PNC vs VSMC cultures. We will functionally assess AII receptors in PNC and VSMC from SHR as compared to WKY and SD by monitoring 45 Ca2+ efflux, cytosolic [Ca2+], phosphoinositide turnover and AII stimulated release of vasopressin (VP). We propose that a major signal pathway mediating AII action in neuronal tissue is the inositol phosphate/Ca2+ pathway. Specific Aim 2: To test the hypothesis that administration of CEI to SHR is associated with down regulation of brain AII receptors. We will a) compare AII receptor number and affinity in PNC and VSMC from SHR, WKY and SD pups subjected to in utero treatment with CEI, b) we will determine the effects of short-term incubation of PNC and VSMC cultures with CEI of different chemical structures on AII binding kinetics. We will study the effects of these agents on the Kd and Bmax and the association and dissociation constants. We will also study the effect of these agents on AII receptor internalization and the coupling of the AII receptor to its second messenger. In order to determine the specificity of the effect of CEI on the AII receptor we will simultaneously monitor the effect of CEI on norepinephrine (NE) and VP binding. Results from the proposed study should increase our understanding of brain AII receptors and the regulation and how these receptors are altered in a genetic model of hypertension.

该提案的长期目标是研究血管紧张素II（AII） 原发性神经元富集（PNC）和血管光滑的受体调节 从SHR，WKY和Sprague-Dawley（SD）大鼠到肌肉细胞（VSMC）培养 检查卡托普利和其他转化酶抑制剂的影响 （CEI）这些大鼠的AII受体调节，并确定是否确定 CEI在SHR中的抗高血压作用与下调有关 脑AII受体。 我们将利用新生儿的PNC和VSMC培养物 比较SHR与正常大鼠中的AII受体调节 确定CEI对中央和周围AII受体的影响。 这 项目分为两个具体目标。 特定目标1：测试 假设大脑AII受体在生化和功能上是 SHR与正常的大鼠菌株和大脑AII受体不同 在SHR中，与WKY和SD大鼠的调节不同。 我们将 利用放射性结合技术来表征AII受体数量 SHR，WKY和 SD幼崽并将其与从同一培养的VSMC中的AII受体进行比较 幼崽。 结合研究将在完整的细胞和膜中进行 从这些细胞中制备。 我们将与已知的剂孵化细胞 刺激或减少AII结合并确定是否存在 SHR与WKY和PNC VS中AII受体反应的差异 VSMC文化。 我们将在PNC和VSMC中进行功能评估AII受体 与WKY和SD相比，通过监测45个Ca2+外排，胞质 [Ca2+]，磷酸肌醇周转率和AII刺激加压素的释放 （VP）。 我们建议在介导AII动作的主要信号途径中 神经元组织是肌醇磷酸/Ca2+途径。 具体目标2： 测试以下假设，即CEI对SHR的施用与 下调脑AII受体的调节。 我们将a）比较AII受体 来自SHR，WKY和SD幼崽的PNC和VSMC的数字和亲和力。 在用CEI治疗的子宫内治疗，b）我们将确定短期的影响 将PNC和VSMC培养物与不同化学的CEI孵育 AII结合动力学的结构。 我们将研究这些影响 KD和BMAX的代理以及关联和解离常数。 我们还将研究这些药物对AII受体的影响 内在化和AII受体的耦合到其第二个 信使。 为了确定CEI对效果的特异性 AII受体我们将同时监视CEI对 去甲肾上腺素（NE）和VP结合。 拟议的研究的结果应 提高我们对大脑AII受体和调节的理解 在高血压遗传模型中，如何改变这些受体。