Dynamic carotid baroreflex control of the peripheral circulation during exercise in humans.
Dynamic carotid baroreflex control of the peripheral circulation during exercise in humans.
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人类运动期间外周循环的动态颈动脉压力反射控制。
DOI：
10.1113/jphysiol.2004.066183
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Smith,MichaelL
中科院分区：
文献类型：
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作者：
Wray,DWalter;Fadel,PaulJ;Keller,DavidM;Ogoh,Shigehiko;Sander,Mikael;Raven,PeterB;Smith,MichaelL
我们试图确定动态运动过程中颈动脉压力反射（CBR）介导的控制与骨骼肌脉管系统的局部控制之间的动态关系。在 12 名受试者（18-35 岁）中，以 0.1 Hz（即 5 秒开启，5 秒关闭）施加振荡颈压 (NP，+40 mmHg) 5 分钟，以确定 CBR 对静息和 7 W 动态期间心率 (HR)、动脉血压 (ABP)、肌肉交感神经活动 (MSNA)、股骨血流速度和骨骼肌组织氧合的控制程度膝关节伸展运动。对运动和非运动腿部的骨骼肌组织氧合测量进行了评估。对 5 分钟片段进行快速傅立叶变换，以计算 R-R 间期 (RRI)、ABP、MSNA、股动脉血流速度和组织氧合时间序列的谱功率，并比较低频（LF，0.085-0.115 Hz）功率谱，以评估每个变量的 CBR 介导的夹带程度。静息时，正弦 NP 显着增加了 RRI、ABP、MSNA 和股骨血流速度的低频频谱功率。运动期间，正弦 NP 引起 RRI 和 MSNA 光谱功率类似的增加，而 CBR 介导的 ABP 和股动脉血流速度的变化与休息时相比减弱。正弦 NP 期间，运动腿和非运动腿休息时骨骼肌组织氧合的光谱功率变化相似。然而，在运动过程中，运动腿的骨骼肌组织氧合能力的变化明显较小，而非运动腿的变化与休息时相似。我们已经证明了所有 CBR 终末器官测量的同时夹带，从心脏变时效应到骨骼肌微循环水平的改变。此外，我们还发现运动肌肉脉管系统中 CBR 介导的交感神经兴奋的终末器官反应性显着且特异性减弱。然而，尽管运动肌肉脉管系统转向更主要的局部控制，但全身动脉血压仍得到很好的保持。
We sought to determine the dynamic relationship between carotid baroreflex (CBR)‐mediated control and local control of the skeletal muscle vasculature during dynamic exercise. In 12 subjects (18–35 years old), oscillatory neck pressure (NP, +40 mmHg) was applied at 0.1 Hz (i.e. 5 s on, 5 s off) for 5 min to determine the degree of CBR control over heart rate (HR), arterial blood pressure (ABP), muscle sympathetic nerve activity (MSNA), femoral blood velocity and skeletal muscle tissue oxygenation at rest and during 7 W dynamic knee‐extension exercise. Skeletal muscle tissue oxygenation measurements of both the exercising and nonexercising leg were evaluated. Fast Fourier transformation was performed on 5 min segments to calculate spectral power of the R–R interval (RRI), ABP, MSNA, femoral blood velocity and tissue oxygenation time series, and the low‐frequency (LF, 0.085–0.115 Hz) power spectra were compared to evaluate the degree of CBR‐mediated entrainment for each variable. At rest, sinusoidal NP significantly increased LF spectral power of RRI, ABP, MSNA and femoral blood velocity. During exercise, sinusoidal NP provoked a similar increase in spectral power for RRI and MSNA, while CBR‐mediated changes in ABP and femoral blood velocity were attenuated compared to rest. Changes in spectral power of skeletal muscle tissue oxygenation during sinusoidal NP were similar between the exercising and nonexercising leg at rest. However, during exercise the changes in skeletal muscle tissue oxygenation power were significantly less in the exercising leg, while changes in the nonexercising leg were similar to rest. We have demonstrated simultaneous entrainment of all CBR end‐organ measurements, ranging from cardiac chronotropic effects to alterations at the level of the skeletal muscle microcirculation. Moreover, we have identified a significant and specific attenuation of end‐organ responsiveness to CBR‐mediated sympathoexcitation in the vasculature of the exercising muscle. However, despite a shift towards more predominant local control over the exercising muscle vasculature, systemic arterial blood pressure was well preserved.