Muscle Pump and Chemical Dilation in Exercise Hyperemia

运动充血中的肌肉泵和化学扩张

• 批准号: 6710162
• 负责人: WILLIAM G SCHRAGE
• 金额: $ 4.73万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6710162
• 关键词: autonomic nervous system; basal metabolism; biomechanics; cardiovascular system; clinical research; electrocardiography; exercise; heart rate; human subject; muscle contraction; muscle metabolism; oxygen consumption; reactive hyperemia; respiratory system; rest; skin circulation; striated muscles; ultrasound blood flow measurement; vascular endothelium; vasodilation; vasodilators

The mechanical effects of the muscle pump and arterial vasodilation are thought to be two important determinants of exercise hyperemia. The contributions of either to exercise hyperemia in humans are not clear. In addition, the possible interactions of chemically induced dilation (e.g. metabolites) and mechanical factors in determining exercise hyperemia have not been determined. The proposed experiments are designed to determine 1) whether increasing resting forearm blood flow alters the hyperemic response to a single mechanical compression or voluntary contraction, 2) whether increasing resting forearm blood flow alters the hyperemic responses to steady state exercise or rhythmic mechanical compression, and 3) whether endothelium-derived vasodilators contribute to the hyperemic response of a single muscle contraction or mechanical compression. This unique approach will measure forearm hyperemia to compression or contraction at three different levels of "resting" blood flow. Most studies of exercise hyperemia focus on the contribution of a single factor, rather than how mechanisms interact. The strength of the proposed experiments is that we will manipulate both mechanical and chemical factors and assess their combined effects on muscle blood flow during acute and steady state exercise in humans.

肌肉泵和动脉血管舒张的机械效应被认为是运动充血的两个重要决定因素。两者对人类运动充血的影响尚不清楚。此外，化学诱导的扩张（例如代谢物）和机械因素在确定运动充血方面可能存在的相互作用尚未确定。所提出的实验旨在确定：1）增加静息前臂血流量是否会改变对单次机械压缩或随意收缩的充血反应，2）增加静息前臂血流量是否会改变对稳态运动或节律性机械压缩的充血反应，以及3）内皮源性血管扩张剂是否有助于单次肌肉收缩或机械压缩的充血反应。这种独特的方法将在三个不同的“静息”血流水平下测量前臂充血至压缩或收缩的情况。大多数运动充血的研究都集中在单个因素的影响上，而不是机制如何相互作用。所提出的实验的优点在于，我们将操纵机械和化学因素，并评估它们在人类急性和稳态运动期间对肌肉血流的综合影响。