Effects of afferents activities from active muscles on cardiovascular and hormonal responses during exercise

我们的目的是研究动脉压力反射和肌肉代谢反射、动脉压力反射和心肺压力反射之间的相互作用，它们各自对肌肉交感神经活动（MSNA）和血压的调节，并通过检查颈动脉压力反射诱导的肌肉交感神经活动（MSNA）、平均动脉血压（MAP）和心率（HR）的改变的时间过程。发生的对MSNA总活性控制的改变可能是对MSNA爆发发生率和爆发强度的压力反射控制改变的结果。这些结果表明，动脉压力反射和肌肉代谢反射相互作用，控制MSNA爆发的发生和强度2)此外，在代谢反射刺激下，颈动脉-压力反射的动态反应被调节，有助于在运动时维持较高的血压3)在轻度直立状态下，发生的对MSNA总活性控制的改变可能是对MSNA爆发发生率和爆发强度的压力反射控制改变的结果。这些结果表明，动脉压力反射和心肺压力反射相互作用，控制体位应激时MSNA爆发的发生和强度4)此外，在轻度体位应激时，颈动脉-压力反射的动态反应被调节，有助于维持血压和限制体位性低血压

We aimed to investigate the interactions between arterial baroreflex and muscle metabo-reflex, and between arterial baroreflex and cardiopulmonary baroreflex, each with respect to the regulation of muscle sympathetic nervous activity (MSNA) and blood pressure, and by examining the time course of the carotid baroreflex-induced alterations in muscle sympathetic nerve activity (MSNA), mean arterial blood pressure (MAP) and heart rate (HR) in humans1)During metaboreflex stimulation, the modification of the control of MSNA total activity that occurs could be a consequence of alterations in the baroreflex control of both MSNA burst incidence and burst strength. These results suggest that the arterial baroreflex and muscle metaboreflex interact to control both the occurrence and strength of MSNA bursts2)Also, during metaboreflex stimulation, carotid-baroreflex dynamic responses are modulated in ways that should help maintain higher blood pressure during exercise3)During mild orthostatic condition, the modification of the control of MSNA total activity that occurs could be a consequence of alterations in the baroreflex control of both MSNA burst incidence and burst strength. These results suggest that the arterial baroreflex and cardiopulmonary baroreflex interact to control both the occurrence and strength of MSNA bursts during orthostatic stress4)Also, during mild orthostatic stress, carotid-baroreflex dynamic responses are modulated in ways that should help maintain blood pressure and limit orthostatic hypotension