Arterial Baroreflex Control of Blood Pressure (Exercise)

动脉压力反射控制血压（运动）

• 批准号: 6616432
• 负责人: PETER Bernard RAVEN
• 金额: $ 35.5万
• 依托单位: UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6616432
• 关键词: aerobic exercise; baroreceptors; baroreflex; blood chemistry; blood pressure; blood volume; cardiac output; cardiovascular pharmacology; carotid body; clinical research; heart rate; human subject; metformin; muscle metabolism; noninsulin dependent diabetes mellitus; physical fitness; potassium channel; vascular smooth muscle nervous control; vasoconstriction

DESCRIPTION (provided by applicant): A number of investigations have demonstrated that arterial baroreflex (CBR) control of blood pressure has a primary role in providing the necessary regulation of the sympathetic neural outflow to active and inactive tissue beds associated with dynamic exercise. In addition, we have documented a reduced vasoconstrictive response to hypotension of the highly trained endurance athlete despite an augmented CBR mediated increase in MSNA. A growing body of evidence suggests that the regulatory role of sympathetic neural outflow to the vasculature is modulated by metabolic by-products released within the active tissue and involve mechanisms of functional sympatholysis. A suggested mechanism of functional sympatholysis is that contraction induced metabolites within the active muscle open ATP-sensitive potassium (KATP) channels and thereby partially inhibit sympathetic vasoconstriction. However, it has recently been demonstrated that the CBR mediated vasoconstriction within the active muscle provides the greatest reflex vasoconstrictor response to hypotension during exercise. Therefore, we hypothesize that the CBR has a fundamental role in the control of MSNA and skeletal muscle vasculature at rest and during exercise. Furthermore, we contend that the CBR regulation of vasomotor function in exercising muscle is altered by local metabolic by-products and their interaction with other vasoactive substances and the KATP channels of the vascular smooth muscle within the active tissue. In addition, these mechanisms of CBR control of the vasculature are modulated by endurance exercise training. To address these hypotheses: Comparisons of carotid baroreflex function curves of blood pressure (BP), MSNA and leg vascular conductance (LVC) will be made between rest, the non-exercising leg (NEL) and the exercising leg (EL) using the classic one-legged exercise protocol performed by humans. Carotid baroreflex function will be assessed using our well established modeling technique. Comparisons of CBR function curves of BP, MSNA and LVC will be made at rest, in the NEL and the EL (except MSNA) between average fit, high fit endurance trained athletes and NIDDM patients treated with glibenclamide and NIDDM patients treated with Metformin. We anticipate that the findings obtained from this project will provide a comprehensive understanding of the fundamental mechanisms involved in the regulation of arterial blood pressure by the arterial baroreflex and its influence on the regulation of vasomotion in active muscle tissue and inactive muscular tissue in matching blood flow to oxygen demand during exercise in humans. These findings will have implications for the care of patients suffering from non-insulin dependent diabetes mellitus (NIDDM), hypertension and cardiac failure.

描述（由申请人提供）：许多研究表明，血压的动脉压力反射（CBR）控制在提供对与动态运动相关的主动和不活跃组织床的必要调节方面具有主要作用。此外，尽管CBR介导的增加了MSNA的增加，但我们还记录了对训练有素的耐力运动员低血压的血管收缩反应减少。越来越多的证据表明，交感神经流向脉管系统的调节作用是由在活性组织中释放的代谢副产物调节的，涉及功能性交感神经解析的机制。功能性交感神经解的建议机制是，收缩诱导的活性肌肉开放式ATP敏感钾（KATP）通道中的代谢产物，从而部分抑制交感神经血管收缩。但是，最近已经证明，活性肌肉内的CBR介导的血管收缩为运动过程中对低血压的反射血管收缩反应最大。因此，我们假设CBR在静止和运动过程中的MSNA和MSNA和骨骼肌脉管系统中具有基本作用。此外，我们认为，局部代谢副产物的CBR调节在运动肌肉中的CBR调节及其与其他血管活性物质和活性组织中血管平滑肌的KATP通道的相互作用改变了。此外，这些脉管系统的CBR控制机制是通过耐力运动训练来调节的。为了解决这些假设：将使用由人类执行的经典的单与运动方案进行颈动脉压力反射功能曲线（BP），MSNA和腿血管电导（LVC）（LVC）（LVC）的比较。颈动脉压力反射功能将使用我们建立的建模技术进行评估。 BP，MSNA和LVC的CBR功能曲线的比较将在NEL和EL（MSNA除外）进行平均拟合，高耐受耐力训练的运动员与接受glibenclamide和NIDDM患者治疗的NIDDM患者之间进行比较。我们预计，从该项目获得的发现将提供对动脉压力反射调节动脉血压涉及的基本机制的全面理解，及其对活性肌肉组织中血管舒张的影响，在人类运动过程中对血液流动匹配的血液流动到氧气需求匹配的血液流动，使血液流动匹配氧气。这些发现将对患有非胰岛素依赖性糖尿病（NIDDM），高血压和心力衰竭患者的护理产生影响。