Exercise Training and Vagal-Cardiac Function in Elderly

描述(由申请者提供)：已在年轻人中演示 有氧运动训练增强心脏副交感神经(或迷走神经) 神经活动。这种改善的迷走神经-心脏功能具有心脏保护作用。 最近，我们发现一种动脉血压(ABP)调节受损 老年患者与年龄相关的迷走神经功能障碍有关。自.以来 衰老伴随着慢性缺乏体力活动，问题仍然存在 有氧运动训练能否逆转迷走神经功能障碍 老年人。我们假设老年人有更多的相对有氧运动 能力会比他们的年龄对心脏有更大的自主神经控制能力 匹配的对应者和增强的迷走-心脏调制导致 运动训练将有助于APB在休息时和在 立位挑战。我们将通过随机评估来检验这些假设 心功能的中介控制与血压的压力感受性反射控制 在受过训练和未受过训练的65-75岁老年受试者中。有选择性的 M受体阻滞剂和β1-肾上腺素能受体阻滞剂将用于确定疗效 在自主神经的特定神经区进行耐力训练 运动训练影响心脏的控制。此外， 运动训练将通过比较未受过训练的老年受试者进行评估 在一年的中等强度有氧运动训练前和一年后。我们的 长期目标是了解尽管是监管机制， 为血压和血量随年龄增长而使用提供依据 采取预防措施，提高人类的生活质量。

DESCRIPTION (provided by applicant): It has been demonstrated in young adults that aerobic exercise training enhances cardiac parasympathetic (or vagal) nerve activity. This improved vagal-cardiac function is cardioprotective. Recently, we found that a compromised arterial blood pressure (ABP) regulation in elderly adults was associated with an age-related vagal dysfunction. Since aging is accompanied by chronic physical inactivity, questions remain as to whether aerobic exercise training can reverse the vagal dysfunction manifest in the elderly. We hypothesize that elderly adults with greater relative aerobic capacity will have greater autonomic neural control of the heart than their age matched counterparts and that the enhanced vagal-cardiac modulation resulting from exercise training will assist in APB stability at rest and during orthostatic challenge. We will test these hypotheses by evaluating vagally mediated control of cardiac function and baroreflex control of blood pressure in trained and in untrained elderly subjects aged 65 - 75 years. Selective muscarinic and beta1-adrenergic blockade will be used to determine the effects of endurance training on the specific neural area of the autonomic neural control of the heart affected by exercise training. Additionally, the effect of exercise training will be assessed by comparing untrained elderly subjects before and after one year of moderate intensity aerobic exercise training. Our long-term objectives are to understand the albeit regulatory mechanisms of blood pressure and blood volume due to age and to provide the basis for the use of prophylactic measure to improve the quality of human life.