Sato Kohei, Moriyama Mayumi, Sadamoto Tomoko
Research Institute of Physical Fitness, Japan Women's College of Physical Education, Tokyo, 157-8565, Japan.
Exp Physiol. 2009 Nov;94(11):1139-46. doi: 10.1113/expphysiol.2009.048587. Epub 2009 Jul 31.
This study evaluated the role of central command in the regulation of common carotid artery blood flow and middle cerebral artery mean flow velocity (V(MCA)) at the onset of arm exercise. Eleven young women performed 2 min voluntary elbow flexion and extension exercise with no load (VOL) that was considered to activate both central command and the muscle mechanoreflex, and 2 min passive elbow flexion and extension exercise (PAS) that was considered to activate only the muscle mechanoreflex. Immediately before the onset of VOL, and V(MCA) began to increase from the baseline and peaked 5 s thereafter (mean +/- s.d.; 20 +/- 5 and 14 +/- 5%, respectively; P < 0.05). Also, VOL increased heart rate (9 +/- 2%; P < 0.05) and cardiac output (16 +/- 3%; P < 0.05). Indexes of the cerebrovascular resistance (MAP/ and MAP/V(MCA)) were reduced at the onset of VOL (13 +/- 4 and 12 +/- 4%, respectively; P < 0.05). However, there were no significant changes in these parameters during PAS. These results suggest that central command plays an important role in the increase of cerebral blood flow at the onset of voluntary exercise.
本研究评估了中枢指令在手臂运动开始时对颈总动脉血流和大脑中动脉平均血流速度（V（MCA））调节中的作用。11名年轻女性进行了2分钟无负荷的自愿性屈肘和伸肘运动（VOL），该运动被认为可激活中枢指令和肌肉机械反射；以及2分钟的被动屈肘和伸肘运动（PAS），该运动被认为仅激活肌肉机械反射。在VOL开始前即刻，V（MCA）开始从基线水平升高，并在随后5秒达到峰值（平均值±标准差；分别为20±5%和14±5%；P<0.05）。此外，VOL使心率升高（9±2%；P<0.05）和心输出量增加（16±3%；P<0.05）。在VOL开始时，脑血管阻力指标（MAP/V（MCA）和MAP/）降低（分别为13±4%和12±4%；P<0.05）。然而，在PAS期间这些参数无显著变化。这些结果表明，中枢指令在自愿运动开始时脑血流量增加中起重要作用。
