SYMPATHETIC NERVOUS SYSTEM INFLUENCE ON BLOOD PRESSURE REGULATION W/AGE

交感神经系统对血压调节随年龄的影响

• 批准号: 6264017
• 负责人: PAMELA P JONES
• 金额: $ 3.22万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 1999-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6264017
• 关键词: age difference; aging; blood pressure; clinical research; exercise; heart rate; human subject; isoproterenol; neuroregulation; phenylephrine; sympathetic nervous system

Arterial blood pressure (BP) exerts a critical influence on physiological homeostasis in humans, and abnormalities in BP regulation have potential pathophysiological consequences. The autonomic nervous system (ANS) is a key regulator of the cardiovascular determinants of BP. There may be age-related changes in ANS support of arterial blood pressure, and these may be at least partially related to differences in adrenergic sensitivity. The general aims of this study are to test the hypotheses that: 1) basal ANS tone makes a significant contribution to the maintenance of resting BP and its circulatory determinants in the healthy adult human; 2) ANS supoort of BP is increased with primary (healthy) aging; 3) adrenergic sensitivity is reduced with primary aging, and 4) regular exercise alters the ANS-cardiovascular integration. To test these hypotheses we are using the autonomic ganglionic antagonist, Trimethaphan, to eliminate ANS input to cardiovascular tissues, and thereby quantify its contribution to the maintenance of BP. The adrenergic agonists pheynlephrine (alpha-agonist), and isproterenol (beta-agonist) are infused during measurements of heart rate, BP and calf blood flow, to determine adrenergic sensitivity (i.e., effector tissue responsiveness to adrenergic stimuli). Four groups of healthy subjects are being studied; 10 young sedentary, 10 young endurance exercise-trained, 10 older sedentary, and 10 older endurance exercise-trained. Preliminary results indicate the ANS support of basal BP is greater in older than young sedentary adults, and that alpha-adrenergic sensitivity is enhanced with exercise training.

动脉血压（BP）对人体的生理稳态产生重要影响，BP调节异常具有潜在的病理生理后果。自主神经系统（ANS）是血压心血管决定因素的关键调节器。ANS对动脉血压的支持可能存在年龄相关的变化，这些变化可能至少部分与肾上腺素敏感性的差异有关。本研究的总体目的是检验以下假设：1）基础ANS张力对健康成年人静息BP及其循环决定因素的维持有显著贡献; 2）ANS对BP的支持随着初级（健康）老化而增加; 3）肾上腺素敏感性随着初级老化而降低; 4）定期运动改变ANS-心血管整合。为了验证这些假设，我们使用自主神经节拮抗剂Trimethaphan来消除ANS对心血管组织的输入，从而量化其对维持BP的贡献。在测量心率、BP和小腿血流量期间输注肾上腺素能激动剂菲那普利（α-激动剂）和异丙肾上腺素（β-激动剂），以确定肾上腺素能敏感性（即，效应器组织对肾上腺素能刺激的反应性）。四组健康受试者进行了研究; 10名年轻久坐，10名年轻耐力运动训练，10名老年久坐，10名老年耐力运动训练。初步结果表明，基础BP的ANS支持是更大的老年人比年轻的久坐不动的成年人，和α-肾上腺素能的敏感性增强与运动训练。