Yamaguchi Yuji, Ikemura Tsukasa, Hayashi Naoyuki
Graduate School of Human-Environment Studies, Kyushu University, Kasuga, Fukuoka 816-8580, Japan ; Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8852, Japan.
Graduate School of Human-Environment Studies, Kyushu University, Kasuga, Fukuoka 816-8580, Japan ; Graduate School of Decision Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8852, Japan ; Faculty of Sports Sciences, Waseda University, Tokorozawa, Saitama 359-1192, Japan.
Biomed Res Int. 2015;2015:671063. doi: 10.1155/2015/671063. Epub 2015 Mar 19.
Neurovascular coupling (NVC) is assessed as an increase response to visual stimulation, and is monitored by blood flow of the posterior cerebral artery (PCA). To investigate whether exhaustive exercise modifies NVC, and more specifically, the relative contributions of vasodilatation in the downstream of PCA and the pressor response on NVC, we measured blood flow velocity in the PCA (PCAv) in 13 males using transcranial Doppler ultrasound flowmetry during a leg-cycle exercise at 75% of maximal heart rate until exhaustion. NVC was estimated as the relative change in PCAv from the mean value obtained during 20-s with the eyes closed to the peak value obtained during 40-s of visual stimulation involving looking at a reversed checkerboard. Conductance index (CI) was calculated by dividing PCAv by mean arterial pressure (MAP) to evaluate the vasodilatation. At exhaustion, PCAv was significantly decreased relative to baseline measurements, and the PCAv response to visual stimulation significantly decreased. Compared to baseline, exhaustive exercise significantly suppressed the increase in MAP to visual stimulation, while the CI response did not significantly change by the exercise. These results suggest that exhaustive exercise attenuates the magnitude of NVC by blunting the pressor response to visual stimulation.
神经血管耦合（NVC）通过对视觉刺激的增加反应来评估，并通过大脑后动脉（PCA）的血流进行监测。为了研究力竭运动是否会改变NVC，更具体地说，是PCA下游血管舒张和压力反应对NVC的相对贡献，我们在13名男性进行腿部循环运动时，使用经颅多普勒超声血流仪测量了PCA中的血流速度（PCAv），运动强度为最大心率的75%，直至力竭。NVC通过PCAv从闭眼20秒期间获得的平均值到观看反转棋盘的40秒视觉刺激期间获得的峰值的相对变化来估计。通过将PCAv除以平均动脉压（MAP）来计算传导指数（CI），以评估血管舒张。力竭时，PCAv相对于基线测量值显著降低，对视觉刺激的PCAv反应也显著降低。与基线相比，力竭运动显著抑制了对视觉刺激的MAP升高，而运动后CI反应没有显著变化。这些结果表明，力竭运动通过减弱对视觉刺激的压力反应来减弱NVC的幅度。
