ACUTE BARORECEPTOR RESETTING: NORMOTENSION AND HYPERTEN

压力感受器急性重置：正常血压和高血压

• 批准号: 3449225
• 负责人: Cheryl M Heesch
• 金额: $ 5.07万
• 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 1987-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3449225
• 关键词: baroreceptors; carotid sinus; efferent nerve; electrophysiology; homeostasis; hypertension; mechanoreceptors; ouabain; reflex; sympathetic nervous system; vascular smooth muscle; viscosity

The arterial baroreceptors play a major role in the regulation of sympathetic activity and of arterial blood pressure in acute cardiovascular stresses such as hemorrhage and in pathophysiologic states such as hypertension. Activation of the arterial baroreceptors during a rise in arterial pressure provokes a reflex inhibition of sympathetic activity and a buffering of the rise in arterial pressure. The level of arterial pressure at which these receptors will fire and the sensitivity of their activation by the rise in pressure is therefore an important determinant of the neural regulation of arterial pressure. For example, in hypertensive states, these baroreceptors are "reset" so that they fire at a higher pressure and their sensitivity is reduced, contributing to the sustained elevation of arterial pressure. This phenomenon of resetting may be demonstrated with temporary elevations of arterial pressure over a period of 10-15 minutes (acute resetting). The purpose of these studies is to examine: 1) the basic mechanisms involved in the phenomenon of acute resetting of arterial baroreceptors: specifically, the contribution of changes in mechanical (viscoelastic) properties of the carotid sinus region to baroreceptor resetting versus the contribution of possible changes in the receptor membrane; (2) the influence of the resetting on efferent sympathetic activity and the possible role of "central resetting" versus the peripheral resetting which is known to occur at the level of the baroreceptor; and 3) the potential importance of "acute resetting" in the reflex control in hypertensive animals. In order to assess the mechanism(s) of peripheral resetting, both multifiber and single unit afferent carotid baroreceptor discharge will be recorded during treatments that produce or attenuate the resetting process. Diameter of the carotid sinus will be measured simultaneous with baroreceptor discharge in some experiments. Central mechanisms will be examined by manipulating the central afferent input (stimulation of afferent nerves) and observing the effects on reflex control of efferent sympathetic nerve activity. "Acute resetting" in hypertensive and normotensive rabbits will be compared and the mechanisms explored. These studies will clarify the role of an important phenomenon in reflex neurogenic control of the circulation and permit examination of the basic mechanisms involved in this phenomenon in physiologic and pathophysiologic states.

动脉压力感受器在调节动脉压力中起主要作用。 急性心血管病患者交感神经活性和动脉血压变化 应力，如出血和病理生理状态， 高血压 动脉压力感受器在血压升高时的激活 动脉压引起交感神经活动的反射抑制， 动脉压上升的缓冲。 动脉水平 这些感受器将发射的压力和它们的敏感性。 因此，由压力升高引起的活化是 动脉压的神经调节 例如，在高血压 在美国，这些压力感受器被“重置”，使它们在更高的温度下发射。 压力和敏感性降低，有助于持续的 动脉压升高。 这种重置现象可以通过临时升高来证明 在10-15分钟的时间内（急性重置）动脉压。 的 这些研究的目的是研究：1）涉及的基本机制 动脉压力感受器的急性重置现象： 具体而言，机械（粘弹性） 颈动脉窦区对压力感受器重置的特性与 受体膜可能变化的贡献;（2） 重置对传出交感神经活动的影响以及 “中央复位”与外围复位的可能作用， 已知发生在压力感受器的水平;和3）电位 急性重调定在高血压反射控制中的重要性 动物 为了评估外周重置的机制， 多纤维和单一单位传入颈动脉压力感受器放电将是 在产生或减弱复位的治疗期间记录 过程 将同时测量颈动脉窦直径， 压力感受器放电在一些实验中。 中央机制将是 通过操纵中枢传入输入（刺激 传入神经），观察对传出神经反射控制的影响 交感神经活动 高血压和高血压病患者的“急性重置” 将与血压正常的兔子进行比较并探讨其机制。 这些研究将阐明反射中一个重要现象的作用 神经原性控制的循环和许可证的基本检查 生理和病理生理学机制参与这一现象 states.