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，老年人长期脱水，尽管 无法很好地理解无法维持欧文的原因。 脱水会导致循环和温度调节障碍， 特别是在体育锻炼或热量暴露期间，并将 患心血管和热有关的风险增加 受伤。 该项目的总体假设是： 答：老年人的相对脱水部分是 身体上的不活动，是由于涉及的系统的死皮 维持细胞外流体体积。 B.A体育锻炼计划将改善体液 调节，从而恢复循环和热调节电位。 该项目的第一个目的是确定 老年人的慢性脱水并确定这些是如何 通过增加的体育锻炼而逆转。 我们将脱水并补水 老年人确定监管回路中的赤字部位。 在耐力训练过程中，我们将重复研究 程序。 第二个目的是测试假设a）低血量 限制老年人在物理期间进行温度调节的能力 活动或热量暴露和b）体育活动增加会引起 血液体积扩张，从而提高了体温调节的能力 在标准练习/热量方案中。 尚不清楚是否年龄较大 人们保留扩大血液量的能力。 第三个目的是表征心肺（CP）BaroreFlex 在培训计划之前和期间，老年人的敏感性。 CP 压力反射敏感性会影响动脉血压调节； 因此，CP Baroreflex灵敏度的变化可能涉及 随着年龄的增长而进行的渐进障碍。 CP BaroreFlex灵敏度也会影响 体液平衡；高灵敏度，与不合适有关 个人将导致较低的血液体积。 我们将测试 假设老年人的CP降压力敏感性很高 不合适的年轻人，而CP BaroreFlex敏感性将降低 随着健身的增加。 通过确定与慢性脱水相关的机制 不活跃的老年人以及可以改变这些的程度 活动;并通过确定是否有血量的能力 扩张及其相关的好处随着年龄的增长而保留； 并确定CP BaroreFlexes是否随着年龄的年龄而改变 活动，我们希望能够深入了解与之相关的机制 衰老的功能降低以及功能的改善如何 由活动增加引起。