ARTERIAL BAROREFLEX CONTROL OF BLOOD PRESSURE-- EXERCISE

描述（申请人的摘要）：先前，我们已经证明， 动态运动时颈动脉压力感受性反射对血压的控制， 经典地重置到动态锻炼的主要血压。 主动脉压力反射对心率的控制也被重置为占优势的血液 压力而不改变最大增益。此外，我们的研究结果表明， 在休息时，动脉压力感受器反射功能由有氧适应性调节， 心肺压力感受器负荷和肌内压力增加。 然而，1）动脉压力感受性反射在 运动，2）肌肉压力的增加和 动脉压力感受性反射功能; 3）有氧健身对动脉压力感受性反射功能的影响。 心肺压力感受器反射功能保持在规定范围内。我们假设 中央指令的前馈机制重置了 与运动活动的诱导和这种活动的连续调制平行， 复位是通过激活肌肉内的机械感受器来提供的， 活性组织我们进一步假设，有氧健身的增加 导致血容量增加和主动脉复位， 心肺压力反射为了验证这些假设，我们将使用 历史上独特实验范例，其中肌肉肌腱振动将 用于有选择地增加或减少中央指挥。在稳定 状态运动（恒定运动加压反射输入），有和没有 肌肉肌腱振动，颈动脉压力反射功能将 使用我们实验室开发的程序进行测定。使用类似的 实验范式和用下半身增加肌内压力 正压力，中央指挥和肌肉之间的相互作用， 将检查压力。此外，使用我们开发的技术 MSNA、NE溢出和下肢血管传导性实验室检查 将选择性地模拟高血压患者的主动脉和心肺压力反射， 低适应耐力运动训练的对象。这其中一个独特的方面是 调查的一个重要目的是，所获得的数据与健康相关。 人类，并将提供重要的基本信息， 体力活动对血压调节作用的研究 患有心力衰竭高血压和间歇性跛行

DESCRIPTION (Applicant's abstract): Previously, we have demonstrated that the carotid baroreflex control of blood pressure during dynamic exercise is classically reset to the prevailing blood pressure of the dynamic exercise. Aortic baroreflex control of heart rate was also reset to the prevailing blood pressure without a change in maximal gain. Additionally, our findings suggest that at rest the arterial baroreflex function is modulated by aerobic fitness, cardiopulmonary baroreceptor load and increases in the intramuscular pressure. However, the mechanisms by which 1) the arterial baroreflexes are reset during exercise, 2) the interaction between increases in muscle pressure and the arterial baroreflex function, and 3) the effect of aerobic fitness on arterial and cardiopulmonary baroreflex function remain to the defined. We hypothesize that the feed forward mechanism of central command resets the baroreflexes in parallel with the induction of motor activity and continuous modulation of this resetting is provided by activation of intramuscular mechanoreceptors within the active tissue. We further hypothesize that increases in aerobic fitness results in an increased blood volume and a resetting of the aortic and cardiopulmonary baroreflex. In order to test these hypotheses we will use a historically unique experimental paradigm in which muscle tendon vibration will be used to selectively increase or decrease central command. During steady state exercise (a constant exercise pressor reflex input) with and without muscle tendon vibration, carotid arterial baroreflex function will be determined using procedures developed in our laboratory. Using a similar experimental paradigm and increasing intramuscular pressure by using lower body positive pressure, the interactions between central command and intramuscular pressure will be examined. Additionally, using techniques developed in our laboratory and measures of MSNA, NE spill-over and leg vascular conductance we will selectively model the aortic and cardiopulmonary baroreflexes of high and low fit endurance exercise trained subjects. A unique aspect of this investigation is that the data obtained is immediately relevant to the healthy human and will provide significant fundamental information for the investigation of blood pressure regulation during physical activity of patients with heart failure, hypertension and intermittent claudication.