BARORECEPTOR REFLEX INTERACTIONS WITH ANGIOTENSION

压力感受器反射与血管紧张素的相互作用

• 批准号: 3449230
• 负责人: KIRK W BARRON
• 金额: $ 5.4万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-09-01 至 1986-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3449230
• 关键词: angiotensin II; arginine vasopressin; baroreceptors; cardiac output; centrally acting drug; electrophysiology; heart rate; hypertension; phenylephrine; sympathetic nervous system; ultrasound blood flow measurement; vascular resistance; water drinking behavior

The purpose of this proposal is to investigate the interaction between arterial baroreceptor reflexes and the actions of angiotensin (II) on the central nervous system. Previous work by this applicant has indicated that conscious sinoaortic baroreceptor denervated rats are 3.6 times more sensitive to the pressor effects of intravenous bolus injection of angiotensin than are baroreceptor intact rats. In comparison, the baroreceptor denervated group was more than 1000 times more sensitive to the pressor effects of central (intracerebroventricular) angiotensin administration. The first specific objective of this study will be to more rigorously define the extent of this very marked inhibitory influence of the baroreflex on the central pressor actions of angiotensin. Experiments are proposed to determine: (1) if the potentiation persists during constant interacerebroventricular infusion of angiotensin, (2) the contribution of cardiac output versus peripheral resistance to the augmentation, (3) if the central actions of blood-borne angiotensin are augmented with baroreceptor denervation, (4) if the potentiation occurs with other centrally acting pressor agents, and (5) if a noncardiovascular action of central angiotensin, such as drinking, is affected by baroreceptor denervation. The second specific objective of this propsal will be to examine the influence of angiotensin on baroreflex function. This approach will examine the pressor sensitivity to continuous infusion of angiotensin in baroreceptor intact versus denervated animals and will include a comparison with baroreflex influences on pressor sensitivity to phenylephrine and vasopressin. The possible influence of angiotensin on baroreflex function will also be examined in anesthetized rats during simulated baroreceptor activation by electrical stimulation of the aortic depressor nerve while recording peripheral sympathetic nerve activity. As further test of the contribution of the central action of angiotensin, experiments will be repeated with a specific knife-cut in the anterior hypothalamus which eliminates the central pressor effects of angiotensin. These types of approaches will provide further understanding of neural circulatory control specifically relating to baroreflex influences on the central action of angiotensin and, conversely, the influence of angiotensin on baroreflex control of arterial pressure.

本提案的目的是调查 动脉压力感受性反射和血管紧张素（II）对 中枢神经系统 本申请人以前的工作表明， 清醒的窦主动脉压力感受器失神经大鼠比正常大鼠高3.6倍， 对静脉推注的升压作用敏感 压力感受器完整大鼠的血管紧张素。 相比较而言， 压力感受器去神经组对压力的敏感性高出1000倍以上 中枢（脑室内）血管紧张素的升压作用 局 这项研究的第一个具体目标是， 严格定义这种非常明显的抑制作用的程度， 压力感受性反射对血管紧张素中枢升压作用的影响。 实验 建议确定：（1）如果增强持续期间 （2）血管紧张素的持续室间输注， 心输出量与外周阻力对 增强，（3）如果血源性血管紧张素的中枢作用是 增强与压力感受器去神经，（4）如果增强发生 与其他中枢作用的升压剂，和（5）如果非心血管 中枢血管紧张素的作用（例如饮酒）受到以下因素的影响 压力感受器去神经 本提案的第二个具体目标是 将检查血管紧张素对压力反射功能的影响。 这种方法将检查持续输注的升压敏感性 血管紧张素在压力感受器完整与失神经动物， 包括与压力反射对升压敏感性影响的比较， 苯肾上腺素和加压素。 血管紧张素可能对 还将在麻醉大鼠中检查压力反射功能， 通过电刺激主动脉模拟压力感受器激活 同时记录周围交感神经活动。 作为 进一步测试血管紧张素的中枢作用的贡献， 实验将重复与一个特定的刀削减在前 下丘脑，消除血管紧张素的中枢升压作用。 这些类型的方法将提供对神经网络的进一步理解。 循环控制，特别是与压力感受器反射有关， 血管紧张素的中枢作用，反过来，血管紧张素的影响 压力感受器反射控制动脉压