Ogoh Shigehiko, Sato Kohei, Hirasawa Ai, Sadamoto Tomoko
Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama, 350-8585, Japan.
Tokyo Gakugei University, Tokyo, Japan.
J Physiol Sci. 2019 Mar;69(2):375-385. doi: 10.1007/s12576-018-0653-1. Epub 2019 Jan 2.
The present study examined the effect of muscle metaboreflex on blood flow in different cerebral arteries. Eleven healthy participants performed isometric, one-leg knee extension at 30% maximal voluntary contraction for 2 min. Activated muscle metaboreflex was isolated for 2 min by post-exercise muscle ischemia (PEMI). The contralateral internal carotid (ICA), vertebral (VA), and ipsilateral external carotid arteries (ECA) blood flows were evaluated using Doppler ultrasound. The ICA blood flow increased at the beginning of exercise (P = 0.004) but returned to the baseline level at the end of exercise (P = 0.055). In contrast, the VA blood flow increased and it was maintained until the end of the exercise (P = 0.011), while the ECA blood flow gradually increased throughout the exercise (P = 0.001). These findings indicate that isometric exercise causes a heterogeneous cerebral blood flow response in different cerebral arteries. During PEMI, the conductance of the VA as well as that of the ICA was significantly lower compared with the baseline value (P = 0.020 and P = 0.032, at PEMI90), while the conductance of the ECA was not different from the baseline (P = 0.587), suggesting that the posterior and anterior cerebral vasculature were similarly affected during exercise by activation of muscle metaboreceptors, but not in the non-cerebral artery. Since ECA branches from ICA, the balance in the different influence of muscle metaboreflex on ECA (vasodilation via exercise-induced hypertension) and ICA (vasoconstriction) may contribute to the decrease in ICA blood flow at the end of isometric exercise.
本研究考察了肌肉代谢反射对不同脑动脉血流的影响。11名健康参与者以最大自主收缩的30%进行单腿等长膝关节伸展2分钟。运动后肌肉缺血（PEMI）隔离激活的肌肉代谢反射2分钟。使用多普勒超声评估对侧颈内动脉（ICA）、椎动脉（VA）和同侧颈外动脉（ECA）的血流。运动开始时ICA血流增加（P = 0.004），但运动结束时恢复到基线水平（P = 0.055）。相比之下，VA血流增加并持续到运动结束（P = 0.011），而ECA血流在整个运动过程中逐渐增加（P = 0.001）。这些发现表明，等长运动在不同脑动脉中引起异质性脑血流反应。在PEMI期间，VA以及ICA的电导与基线值相比显著降低（PEMI90时，P = 0.020和P = 0.032），而ECA的电导与基线无差异（P = 0.587），这表明运动期间肌肉代谢感受器激活对大脑前后血管系统的影响相似，但对非脑动脉则不然。由于ECA从ICA分支而来，肌肉代谢反射对ECA（通过运动诱发的高血压引起血管舒张）和ICA（血管收缩）的不同影响之间的平衡可能导致等长运动结束时ICA血流减少。
