Noninvasive assessment of sympathetic vasoconstriction in human and rodent skeletal muscle using near-infrared spectroscopy and Doppler ultrasound
Noninvasive assessment of sympathetic vasoconstriction in human and rodent skeletal muscle using near-infrared spectroscopy and Doppler ultrasound
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DOI：
10.1152/japplphysiol.01041.2003
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发表时间：
2004-04-01
影响因子：
3.3
通讯作者：
Thomas, GD
中科院分区：
文献类型：
--
作者：
Fadel, PJ;Keller, DM;Thomas, GD
交感神经系统在运动过程中调节骨骼肌血流量的确切作用一直难以在人类中定义，部分原因是可用于测量活动肌肉中血流量的技术有限。最近使用近红外（NIR）光谱测量组织氧合变化的研究提供了一种替代方法来评估运动肌肉中的血管反应，但这种方法尚未得到充分验证。在这项研究中，我们测试的假设，交感神经激活会引起平行的变化，在休息和运动肌肉的组织氧合和血流量。我们同时测量组织氧合与近红外光谱和血流多普勒超声在清醒的人（n = 13）和麻醉大鼠（n = 9）的骨骼肌。在人的静息前臂中，使用下体负压反射性激活交感神经产生组织氧合和血流量的分级降低，其高度相关（r = 0.80，P < 0.0001）。同样，在大鼠后肢静息状态下，电刺激交感神经引起组织氧合和血流速度的分级降低，两者高度相关（r = 0.93，P < 0.0001）。在节律性肌肉收缩期间，由交感神经激活引起的组织氧合和血流量的减少显著减弱（P，0.05 vs.休息），但在人类（r = 0.80，P < 0.006）和大鼠（r = 0.92，P < 0.0001）中保持高度相关。这些数据表明，在稳态代谢条件下，组织氧合的变化可用于可靠地评估静息和运动骨骼肌中的交感血管收缩。
The precise role of the sympathetic nervous system in the regulation of skeletal muscle blood flow during exercise has been challenging to define in humans, partly because of the limited techniques available for measuring blood flow in active muscle. Recent studies using near-infrared (NIR) spectroscopy to measure changes in tissue oxygenation have provided an alternative method to evaluate vasomotor responses in exercising muscle, but this approach has not been fully validated. In this study, we tested the hypothesis that sympathetic activation would evoke parallel changes in tissue oxygenation and blood flow in resting and exercising muscle. We simultaneously measured tissue oxygenation with NIR spectroscopy and blood flow with Doppler ultrasound in skeletal muscle of conscious humans (n = 13) and anesthetized rats ( n = 9). In resting forearm of humans, reflex activation of sympathetic nerves with the use of lower body negative pressure produced graded decreases in tissue oxygenation and blood flow that were highly correlated ( r = 0.80, P < 0.0001). Similarly, in resting hindlimb of rats, electrical stimulation of sympathetic nerves produced graded decreases in tissue oxygenation and blood flow velocity that were highly correlated ( r = 0.93, P < 0.0001). During rhythmic muscle contraction, the decreases in tissue oxygenation and blood flow evoked by sympathetic activation were significantly attenuated ( P , 0.05 vs. rest) but remained highly correlated in both humans ( r = 0.80, P < 0.006) and rats ( r = 0.92, P < 0.0001). These data indicate that, during steady-state metabolic conditions, changes in tissue oxygenation can be used to reliably assess sympathetic vasoconstriction in both resting and exercising skeletal muscle.