EXERCISE TRAINING AND CORONARY VASCULAR RESPONSIVENESS

心脏和冠状血管接受持续的交感神经刺激， 活动，被称为音调，其调节心率，收缩 强度和冠状血管阻力。 研究表明 在交感神经系统控制中存在潜在的改变， 或心脏和血管的交感神经活动量， 运动训练。 这项研究旨在调查 冠状动脉血神经调节与代谢调节的关系 在运动训练计划中的流动。 检验的假设是： 运动训练增强冠心病患者自主交感神经张力 血管在休息和生理应激状态，如跑步机 锻炼的 对肾上腺素能受体激动剂和拮抗剂的敏感性 将在有意识的狗身上进行研究。 左 将同时测量回旋支冠状动脉血流量， 使用距离选通脉冲多普勒的局部心肌段长度 流量计和超声波尺寸计。 局部冠状动脉血流量 分布将通过微球技术确定。 舒张 将使用舒张主动脉计算冠状动脉血管阻力 血压和左回旋支冠状动脉血流量。 心肌 反应性充血将由血管的阻塞和释放产生， 外控式旋动脉液压封堵器 冠状动脉 冠状动脉血流变化，舒张冠状动脉 血管阻力、心肌段长度和肾上腺素能心率 刺激α-和β-受体激动剂和15秒冠状动脉 将在10周治疗前、治疗期间和治疗后比较动脉闭塞情况 运动训练计划。 药物将使用植入的 冠状动脉导管，避免全身药物作用。 使用这些 技术，有可能仅扰动冠状血管床， 测量清醒狗的总冠状动脉血流量和局部冠状动脉血流量。 我们 也能确定交感神经系统的变化 是真实的，或者如果变化源于代谢， 局部心肌功能 这些研究的长期目标是 描述由于每天的运动而引起的冠状动脉血流控制的变化 在正常人中进行锻炼，然后将这些知识应用于 心血管疾病患者的未来。

The heart and coronary blood vessels receive constant sympathetic neural activity, referred to as tone, which modulates heart rate, contractile strength and coronary vascular resistance. Studies have indicated that there is a potential alteration in the sympathetic nervous system control, or the amount of sympathetic activity to the heart and blood vessels with exercise training. The proposed study was designed to investigate the relationship between the neural and metabolic regulation of coronary blood flow during an exercise training program. The hypothesis tested is: exercise training enhances the autonomic sympathetic tone on coronary vessels at rest and during physiological stress states, such as treadmill exercise. The sensitivity to adrenergic receptor agonists and antagonists will be studied in the chronically instrumented, conscious dog. Left circumflex coronary blood flow will be measured simultaneously with regional myocardial segment length using a range gated, pulsed Doppler flowmeter and ultrasonic dimension gages. Regional coronary blood flow distribution will be determined by the microsphere technique. Diastolic coronary vascular resistance will be calculated using diastolic aortic pressure and left circumflex coronary artery blood flow. Myocardial reactive hyperemia will be produced by occlusion and release of an externally controlled hydraulic occluder implanted around the circumflex coronary artery. Changes in coronary blood flow, diastolic coronary vascular resistance, myocardial segment length and heart rate to adrenergic stimulation of alpha- and beta-receptor agonists and to 15 sec coronary artery occlusions will be compared before, during and after a 10-week exercise training program. Drugs will be administered using an implanted coronary artery catheter, avoiding systemic drug effects. Using these techniques it is possible to perturb only the coronary vascular bed and measure both total and regional coronary blood flow in conscious dogs. We can also determine whether a modification in the sympathetic nervous system is real or if changes are metabolic in origin by simultaneously measuring regional myocardial function. The long term goal of these studies is to describe changes in the control of coronary blood flow due to daily exercise in normal individuals and to then apply this knowledge in the future to individuals with cardiovascular disease.