BODY FLUID REGULATION IN AGING ADULTS WITH EXERCISE

老年人运动后的体液调节

• 批准号: 3121810
• 负责人: ETHAN R NADEL
• 金额: $ 30.52万
• 依托单位: JOHN B. PIERCE LABORATORY, INC.
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-06-15 至 1997-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3121810
• 关键词: aerobic exercise; aging; baroreceptors; blood pressure; blood volume; body fluids; body temperature regulation; body water dehydration; cardiovascular function; human old age (65+); physical fitness

Older people are reported to be chronically dehydrated, although the cause of the inability to maintain euhydration is not well understood. Dehydration results in circulatory and thermoregulatory impairments, particularly during physical activity or heat exposure, and places the individual at an increased risk of cardiovascular and heat-related injury. The overall hypotheses of this project are: A. The relative dehydration in older people is in part the consequence of physical inactivity and is due to deadaptation of the systems involved in maintenance of extracellular fluid volume. B.A physical activity program will result in improvements in body fluid regulation, and thus restore circulatory and thermoregulatory potential. The first aim of the project is to determine the reason(s) for the chronic dehydration in older people and to determine how these are reversed by increased physical activity. We will dehydrate and rehydrate older people to determine the site of deficit in the regulatory circuit. We will repeat the studies during the course of an endurance training program. The second aim is to test the hypotheses that a) a low blood volume restricts the ability of older people to thermoregulate during physical activity or heat exposure and b) increased physical activity induces blood volume expansion, thus improving the ability to thermoregulate during a standard exercise/heat protocol. It is not known whether older people retain the ability to expand blood volume. The third aim is to characterize cardiopulmonary (CP) baroreflex sensitivity in older people before and during a training program. CP baroreflex sensitivity affects arterial blood pressure regulation; therefore, changes in CP baroreflex sensitivity may be involved in the progressive impairment with age. CP baroreflex sensitivity also affects body fluid balance; a high sensitivity, associated with unfit individuals, will result in a lower blood volume. We will test the hypothesis that older people have a high CP baroreflex sensitivity, as do unfit younger people, and that CP baroreflex sensitivity will decrease with increasing fitness. By determining the mechanisms associated with the chronic dehydration in inactive older people and the extent to which these can be changed with activity; and by determining whether the capability for blood volume expansion, and its associated benefits, is retained with advancing age; and by determining whether CP baroreflexes are altered with age or with activity, we hope to provide insight into the mechanisms associated with reductions in function with aging and how improvements in function are induced by increased activity.

据报道，老年人患有慢性脱水，尽管 无法维持水合作用的原因尚不清楚。 脱水会导致循环和体温调节障碍， 特别是在体力活动或高温暴露期间，并将 心血管疾病和中暑风险增加的个人 受伤。这个项目的总体假设是： 答：老年人相对脱水的部分原因是 缺乏体力活动，是由于参与的系统不适应 维持细胞外液的量。 B.体力活动计划将改善体液 调节，从而恢复循环和体温调节潜力。 该项目的第一个目标是确定原因(S) 老年人的慢性脱水，并确定它们是如何 被增加的体力活动所逆转。我们将脱水并重新水化 老年人在调节回路中判断虚弱的部位。 我们将在耐力训练过程中重复这些研究 程序。 第二个目的是检验以下假设：a)低血容量 限制老年人在体力活动中调节体温的能力 活动或热暴露以及b)增加的体力活动会导致 血容量扩张，从而提高体温调节能力 在标准的运动/热疗方案中。目前还不知道年龄是否更大 人们保留着扩大血液容量的能力。 第三个目的是研究心肺压力感受器反射的特征。 老年人在训练计划前和训练期间的敏感性。CP 压力感受性反射敏感性影响动脉血压调节； 因此，CP压力感受性反射敏感性的改变可能与 随年龄增长的进行性损害。CP压力反射敏感性也会影响 体液平衡；高度敏感，与身体不适有关 个人，将导致较低的血量。我们将测试 假设老年人有很高的CP压力感受性反射敏感性，就像这样 不适合年轻人，CP压力感受器反射敏感性会降低 随着健康程度的提高。 通过确定与慢性脱水相关的机制 不活跃的老年人以及这些可以改变的程度 活性；并通过确定血液容量的能力 扩张及其带来的好处随着年龄的增长而保持不变； 并通过确定CP压力反射是否随年龄或随着年龄的变化而改变 活动，我们希望提供对相关机制的洞察 功能随年龄增长而减少，以及功能如何改善 由活动增加引起的。