CAROTID BAROREFLEX CONTROL IN NORMO- AND HYPERTENSION

压力感受器反射在高血压中的作用是 有争议的。拟议的研究将集中在三个方面 高血压患者压力感受器反射功能的变化 在高血压中的作用，在血管活性中的压力感受性反射控制 正常血压、高血压和颈动脉窦的激素释放 血管阻力和容量功能的反射控制 高血压。这些研究将在高血压狗身上进行。 有慢性孤立的颈动脉窦区。结果来自 高血压狗将与正常血压的狗进行比较。 将研究以下可能性：减少对 颈动脉窦本身可能导致功能性丧失。 高血压患者的压力感受性反射控制。压力反射的能力 为了适应当前压力的快速变化，快速 重置过程将在高血压慢性犬身上进行评估。 这一假设将得到检验，即压力感受器反射的变化 所看到的功能发生在受体的水平上； 将使用颈动脉窦传入神经活动的测量 以评估受体-神经特性的变化。抑制 颈动脉窦在对侧窦的作用下， 评估为高血压。颈动脉压力感受性反射释放 血管活性激素将在正常人和高血压患者中进行研究 狗。需要检验的假设是，增加释放的 这些已知的血管活性荷尔蒙在 生理应激有助于维持较高的 高血压患者的血压水平。有待研究的激素包括 加压素、去甲肾上腺素和B-内啡肽。压力反射控制 将检查全身血管阻力的大小。整个 将测量系统压力-流量关系，并 在高血压犬的心脏搭桥术中进行了尖锐的比较。在一个 进一步的一系列实验，颈动脉压力感受性反射的控制 将测量全身血管顺应性。假说 接受检测的是血管顺应性降低和 反射性顺应性的改变可以解释动脉的改变 高血压中的压力调节。在另一系列建议中 实验，颈动脉窦反射对全身血管的控制 容量，特别是无压力的血管容量将是 在高血压犬心脏搭桥术中进行评估。决赛 实验将长期和尖锐地评估 局部血管阻力和容量的不同变化 在高血压方面。这些实验将提供新的和 关于传入和传导机制的重要信息 高血压期间传出压力感受器反射控制。

The role of the baroreceptor reflex during hypertension is controversial. The proposed research will focus on three aspects of baroreflex function in hypertension: changes in receptor function in hypertension, baroreflex control in vasoactive hormone release in normo- and hypertension, and carotid sinus reflex control of vascular resistance and capacity functions in hypertension. The studies will be performed in hypertensive dogs with chronically isolated carotid sinus regions. Results from hypertensive dogs will be compared to normotensive controls. The possibility will be examined that a reduced compliance of the carotid sinus itself could contribute to a loss of functional baroreflex control in hypertension. The ability of the baroreflex to adapt to rapid changes in prevailing pressure, the rapid resetting process will be evaluated in hypertensive chronic dogs. The hypothesis will be tested that the changes in baroreflex function seen are occurring at the level of the receptor; measurement of afferent carotid sinus nerve activity will be used to assess changes in receptor-nerve characteristics. Inhibition of the carotid sinus by the action of the contralateral sinus will be assessed in hypertension. Carotid baroreflex release of vasoactive hormones will be studied in normo- and hypertensive dogs. The hypothesis to be tested is that increased release of these vasoactive hormones known to be released during physiological stresses contributes to the maintenance of elevated pressure levels in hypertension. Hormones to be studied include vasopressin, nor-epinephrine and B-endorphin. Baroreflex control of systemic vascular resistance will be examined. The entire systemic pressure-flow relationship will be measured and compared acutely in hypertensive dogs on cardiac bypass. In a further series of experiments, carotid baroreflex control of systemic vascular compliances will be measured. The hypothesis to be tested is that reduced vascular compliances and diminished reflex changes in compliance can account for the altered arterial pressure regulation in hypertension. In another series of proposed experiments, carotid sinus reflex control of systemic vascular capacity, and particularly unstressed vascular volume, will be assessed in hypertensive dogs on cardiac bypass. The final experiment will assess, both chronically and acutely, the differential changes in regional vascular resistance and capacity in hypertension. These experiments will provide new and important information regarding the mechanisms of afferent and efferent baroreflex control during hypertension.