ARTERIAL BAROREFLEX FUNCTION WITH AGING

一般认为，动脉压力感受性反射控制和迷走神经 心率控制力随着年龄的增长而减弱。 人类。这些现象被用来解释增加的 健康老年人直立性低血压的发生率观察 人口。然而，最近，我们记录了这种离散的 60~69岁健康人颈动脉压力感受性反射对心率的控制 年龄与18-36岁的健康人没有区别 几年前。因此，我们假设，离散的主动脉 压力感受器介导的老年人心率反射控制 个人必须受到损害。其他发现表明，由于 老年人颈动脉-心脏反射控制力的增强 在年轻人中观察到的由中枢性低血容量引起的心率 被削弱了。因此，我们进一步假设， 颈动脉压力感受器反射功能与中心血容量状态的关系 (低血容量或高血容量)在老年受试者(60-75岁)中减少 年)。为了验证这些假设，我们将分离颈动脉和主动脉。 正常血容量、低血容量和低血容量时压力感受性反射对心率的控制 高容量中心血容量的横断面研究 18-36岁的成年人和60-75岁的成年人，男女都有。在……里面 此外，迷走神经对心率控制力的检查 将对所有条件和年龄段进行光谱分析。它 预计所获得的数据将为我们提供对 动脉压力感受性反射改变对心率的调控机制 正处于矫正期的老年人。此外，我们预计将开发一种模型 直立性低血压的进一步研究 与年龄相关的直立性低血压增加的机制可能是 制造。我们的长期目标是了解衰老的机制 关于人体神经体液对血容量和血压的调节 为采取预防措施加强儿童健康提供依据 老年人口的生活质量。

It is generally accepted that arterial baroreflex control and vagal control of heart rate is diminished with increases in age (>60 years) in the human. These phenomena have been used to explain the increased incidence of orthostatic hypotension observed in the healthy older population. More recently, however, we have documented that discrete carotid baroreflex control of the heart rate of healthy individuals 60-69 years of age was no different than that of healthy individuals 18-36 years of age. Therefore, we hypothesize, that the discrete aortic baroreceptor mediated reflex control of heart rate of the older individuals must be compromised. Other findings suggest that as individuals age the augmentation of the carotid-cardiac reflex control of heart rate by central hypovolemia, observed in young adults is diminished. Therefore, we further hypothesize that the interactions of carotid baroreflex function with the status of central blood volume (hypovolemia or hypervolemia) is diminished in older subjects (60-75 years). To test these hypotheses, we will isolate the carotid and aortic baroreflex control of heart rate during euvolemic, hypovolemic and hypervolemic central blood volumes, in a cross-sectional investigation of 18-36 year old adults and 60-75 year old adults of both genders. In addition, examination of the vagal control of heart rate using power spectral analysis will be made across all conditions and age groups. It is anticipated that the data obtained will provide us insight into the mechanism of altered arterial baroreflex control of heart rate of the elderly during orthostasis. Furthermore, we expect to develop a model of orthostatic hypotension upon which further investigations into the mechanisms of the age related increase in orthostatic hypotension can be made. Our long-term objectives are to understand the mechanisms of aging on human neurohumoral regulation of blood volume and blood pressure and to provide the basis for the use of prophylactic measures to enhance the quality of life of the elderly population.