The distribution of blood flow in the carotid and vertebral arteries during dynamic exercise in humans
The distribution of blood flow in the carotid and vertebral arteries during dynamic exercise in humans
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DOI：
10.1113/jphysiol.2010.204461
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发表时间：
2011-06-01
影响因子：
5.5
通讯作者：
Sadamoto, Tomoko
中科院分区：
文献类型：
--
作者：
Sato, Kohei;Ogoh, Shigehiko;Sadamoto, Tomoko
非技术性总结：在最大增量动态运动期间，脑血流量的平台或相对减少的机制仍不清楚。我们发现，在分级动态运动，颈内动脉血流的调节是有限的，颈外动脉血流，其中一个功能是在剧烈运动时的体温调节的大幅增加。颈内动脉血流量的平台或减少的机制似乎部分是由于运动引起的动脉血流量重新分配到头部和大脑，在最大增量动态运动期间的平台或脑血流量（CBF）相对减少的机制尚不清楚。我们假设在高强度的动态运动中，由于颈动脉血流的重新分布，脑灌注受到限制。为了确定供应头部和大脑的动脉之间的血流分布，我们使用多普勒超声在动态运动期间评估颈总动脉（CCA）、颈内动脉（伊卡）、颈外动脉（ECA）和椎动脉（VA）的血流。10名受试者在半仰卧位进行分级骑自行车运动，每种工作量分别为峰值摄氧量的40%、60%和80%（），持续5 min。从休息到60%运动，伊卡血流量增加了23.0 +/- 4.6%（平均值+/- SE）。然而，在80%时，伊卡血流恢复至接近静息水平（9.6 +/- 4.7% vs.静息）。相比之下，ECA，CCA和VA血流量与工作量成比例增加。分级运动时伊卡血流变化与潮气末CO2分压相关（r = 0.72）。伊卡血流从60%到80%的变化与ECA血流的变化呈负相关（r = -0.77）。此外，有额头皮肤血管传导性和ECA血流量在运动过程中（r = 0.79）显着相关。这些结果表明，在高强度动态运动期间，伊卡血流量的平台或减少部分是由于ECA血流量的大幅增加，ECA血流量选择性地增加以优先进行体温调节。
Non-technical summaryThe mechanism underlying the plateau or relative decrease in cerebral blood flow during maximal incremental dynamic exercise remains unclear. We show that during graded dynamic exercise, the regulation of internal carotid artery blood flow was limited by a large increase in external carotid artery blood flow, one function of which is thermoregulation during heavy exercise. The mechanism of the plateau or decrease in internal carotid artery blood flow appears to be partly due to exercise-induced redistribution of arterial blood flow to the head and brain.The mechanism underlying the plateau or relative decrease in cerebral blood flow (CBF) during maximal incremental dynamic exercise remains unclear. We hypothesized that cerebral perfusion is limited during high-intensity dynamic exercise due to a redistribution of carotid artery blood flow. To identify the distribution of blood flow among the arteries supplying the head and brain, we evaluated common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and vertebral artery (VA) blood flow during dynamic exercise using Doppler ultrasound. Ten subjects performed graded cycling exercise in a semi-supine position at 40, 60 and 80% of peak oxygen uptake () for 5 min at each workload. The ICA blood flow increased by 23.0 +/- 4.6% (mean +/- SE) from rest to exercise at 60% . However, at 80% , ICA blood flow returned towards near resting levels (9.6 +/- 4.7% vs. rest). In contrast, ECA, CCA and VA blood flow increased proportionally with workload. The change in ICA blood flow during graded exercise was correlated with end-tidal partial pressure of CO2 (r = 0.72). The change in ICA blood flow from 60% to 80% was negatively correlated with the change in ECA blood flow (r = -0.77). Moreover, there was a significant correlation between forehead cutaneous vascular conductance and ECA blood flow during exercise (r = 0.79). These results suggest that during high-intensity dynamic exercise the plateau or decrease in ICA blood flow is partly due to a large increase in ECA blood flow, which is selectively increased to prioritize thermoregulation.