ARTERIAL BAROREFLEX CONTROL OF BLOOD PRESSURE-- EXERCISE

动脉压力反射控制血压——运动

• 批准号: 6351969
• 负责人: PETER Bernard RAVEN
• 金额: $ 3.71万
• 依托单位: UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6351969
• 关键词: aerobic exercise; aorta; baroreceptors; baroreflex; blood chemistry; blood pressure; blood volume; cardiac output; cardiovascular pharmacology; carotid artery; carotid body; clinical research; heart rate; human subject; physical fitness; respiratory oxygen; rest; vascular smooth muscle nervous control

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.

描述（申请人的摘要）：以前，我们已经证明了 动态运动期间血压的颈动脉降压力控制是 经典地重置为动态运动的主要血压。 主动脉压力反射控制心率也已重置为流行的血液 压力不会改变最大增益。此外，我们的发现建议 在休息时 心肺压力感受器负荷并在肌内压力中增加。 但是，1）在 练习，2）肌肉压力增加与 动脉压力反射功能和3）有氧健身对动脉的影响 和心肺动反射功能保持在定义上。我们假设 中央命令的前馈机制将aroreflexes重置在 与诱导运动活动和连续调制平行 通过激活肌内机械感受器的激活提供重置 活性组织。我们进一步假设有氧健身增加 导致血液量增加和主动脉的重置 心肺动反射。为了检验这些假设，我们将使用 历史上独特的实验范式，其中肌肉肌腱振动将 用于选择性增加或减少中央命令。在稳定期间 没有和没有 肌肉肌腱振动，颈动脉压力反射功能将是 使用我们实验室开发的程序确定。使用类似 实验性范式和通过下半身增加肌内压力 正压，中央命令与肌内之间的相互作用 将检查压力。此外，使用我们在我们的 MSNA，NE溢出和腿血管电导的实验室和测量 将有选择地建模高和心肺的肢体反射。 低拟合耐力运动训练有素的受试者。一个独特的方面 调查是获得的数据与健康有关 人类，将为 调查患者体育活动期间血压调节 具有心力衰竭，高血压和间歇性lau不平。