EFFECTS OF AGING AND EXERCISE ON CARDIOVASCULAR FUNCTION

衰老和运动对心血管功能的影响

• 批准号: 3081927
• 负责人: GEORGE C HAIDET
• 金额: $ 6.54万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 1990-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3081927
• 关键词: aging; animal old age; blood flow measurement; body physical activity; cardiac output; cardiovascular function; environmental stressor; exercise; hemodynamics; histochemistry /cytochemistry; longitudinal animal study; myocardium; oxygen consumption; peripheral nervous system; statistics /biometry; striated muscles; sympathetic nervous system

The overall aim of this proposal is to further investigate age-related alterations in the cardiovascular and skeletal muscular systems. A more sedentary lifestyle, as well as the process of aging, per se, have each been hypothesized as possible explanations for the decline in functional capacity that occurs with advanced age. Additionally, it has been suggested on the basis of minimal evidence that the capability of optimally regaining functional losses by exercising is reduced as aging progresses. The proposed experiments will investigate the effects of aging upon cardiovascular functional capabilities, determine whether age-related changes may be altered by dynamic exercise training, and determine whether chronic exercise accelerates, attenuates, or reverses declines in cardiovascular function that occur during the aging process. Cross-sectional and longitudinal studies, utilizing mature adult and senescent beagles, will be used to determine hemodynamic and regional blood flow responses to stress on an acute and chronic basis. In addition, the significance of adaptive responses of the sympathoadrenal and adrenergic systems upon age-related changes in myocardial function will be investigated before and after chronic exercise. Specific questions to be addressed include: 1) Do functional alterations occur in the myocardium with advanced age? 2) Do significant changes occur in the peripheral circulation during the aging process? 3) Do age-related reductions in endurance occur in skeletal muscle? 4) Do alterations during aging in the adrenergic and sympathoadrenal systems effect functional capacity? 5) What types of adaptation occur within the cardiovascular and skeletal muscular systems in response to dynamic exercise training in senescence? 6) Are age-related changes in myocardial, skeletal muscular, peripheral circulatory, sympathoadrenal, and adrenergic systems altered by chronically increased levels of activity? Regional blood flow will be determined by the radioactive microsphere technique, cardiac output by dye dilution, total body oxygen consumption by the product of arteriovenous oxygen difference and cardiac output, and beta-adrenoreceptor numbers and affinity by radioligand binding. Skeletal muscle histochemistry, biochemistry, and morphometrics will also be evaluated. This work is expected to document diminished functional capabilities that occur with advanced age, as well as the types of adaptive responses that result after chronic exercise. This knowledge may be clinically useful when considering activity levels and dynamic exercise training for the elderly.

这项建议的总体目标是进一步调查与年龄有关的 心血管和骨骼肌系统的改变。A更多 久坐的生活方式，以及衰老的过程，本身都有 被假设为功能性功能下降的可能解释 随着年龄的增长而出现的能力。此外，它一直是 根据最少的证据表明，最优的 随着年龄的增长，通过运动恢复的功能损失会减少。 拟议中的实验将调查衰老对 心血管功能，决定是否与年龄相关 动态运动训练可以改变变化，并确定是否 长期锻炼可加速、减弱或逆转运动能力的下降 在衰老过程中发生的心血管功能。 横断面和纵向研究，利用成熟成虫和 衰老的小猎犬，将被用来测定血流动力学和局部血液 在急性和慢性基础上对压力的心流反应。此外， 交感肾上腺和肾上腺素能神经元适应性反应的意义 系统对年龄相关的心肌功能的改变将是 分别在慢性运动前后进行调查。有待回答的具体问题 涉及的问题包括：1)心肌是否发生功能改变 随着年龄的增长？2)外周有显著变化吗？ 衰老过程中的循环？3)与年龄相关的血液循环减少 耐力发生在骨骼肌中？4)人在衰老过程中会发生变化吗 肾上腺素能和交感肾上腺系统影响功能能力？5)什么 适应的类型发生在心血管和骨骼肌内 对衰老中的动态运动训练的反应系统？6) 心肌、骨骼肌、外周组织的增龄性变化 慢性疾病引起的循环系统、交感肾上腺系统和肾上腺素能系统的改变 活动水平的提高？区域血流量将由以下因素决定 放射性微球技术，染料稀释法的心输出量， 动静脉氧量乘积计算的全身耗氧量 差异和心输出量，β-肾上腺素受体数量和亲和力 通过放射性配基结合。骨骼肌组织化学、生物化学和 形态计量学也将被评估。这项工作预计将记录 随着年龄的增长而出现的功能能力减弱，以及 慢性运动后产生的适应性反应的类型。这 当考虑到活动水平和 面向老年人的动态运动训练。