Hellström G, Fischer-Colbrie W, Wahlgren N G, Jogestrand T
Department of Neurology, Karolinska Hospital, Stockholm, Sweden.
J Appl Physiol (1985). 1996 Jul;81(1):413-8. doi: 10.1152/jappl.1996.81.1.413.
Factors controlling cerebral blood flow (CBF) during exercise are complex and incompletely known. Different techniques have shown partly contradictory results of changes in regional and global cerebral perfusion during dynamic exercise in healthy subjects. To elucidate the global CBF response to supine stepwise increasing physical exercise, we measured blood flow in the left common carotid artery (QCCA) and the left internal carotid artery (QICA) simultaneously with the blood flow velocity in the ipsilateral middle cerebral artery (VMCA) using duplex ultrasonography and transcranial Doppler ultrasonography. During moderate exercise intensity (60-67% of maximal capacity), the VMCA increased 14% (P < 0.001), the QICA 17% (P < 0.01), and the QCCA 33% (P < 0.001) compared with baseline values. High physical exercise intensity (80-90% of maximal capacity) tended to reduce VMCA and QICA compared with moderate exercise, in contrast to a continued increase in QCCA. The results indicate an increased global CBF during exercise. This increase was reduced during hard exercise due to a decrease of the arterial PCO2 secondary to hyperventilation.
运动期间控制脑血流量（CBF）的因素复杂且尚未完全明确。不同技术显示，健康受试者在动态运动期间局部和整体脑灌注变化的结果存在部分矛盾。为阐明仰卧位逐步增加体力运动时的整体CBF反应，我们使用双功超声和经颅多普勒超声同时测量了左颈总动脉（QCCA）和左颈内动脉（QICA）的血流量以及同侧大脑中动脉（VMCA）的血流速度。在中等运动强度（最大能力的60 - 67%）时，与基线值相比，VMCA增加了14%（P < 0.001），QICA增加了17%（P < 0.01），QCCA增加了33%（P < 0.001）。与中等运动相比，高强度体力运动（最大能力的80 - 90%）时VMCA和QICA有降低趋势，而QCCA持续增加。结果表明运动期间整体CBF增加。由于过度通气导致动脉PCO2降低，剧烈运动时这种增加有所减少。
