Shotaro Saito1, Takuro Washio1, Hironori Watanabe1, Keisho Katayama2, Shigehiko Ogoh3,4. 1. Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama, 350-8585, Japan. 2. Research Center of Health, Physical Fitness, and Sports, Graduate School of Medicine, Nagoya University, Nagoya, Japan. 3. Department of Biomedical Engineering, Toyo University, 2100 Kujirai, Kawagoe-shi, Saitama, 350-8585, Japan. ogoh@toyo.jp. 4. Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK. ogoh@toyo.jp.
Abstract
PURPOSE: Change in cardiac output (Q) contributes to cerebral blood flow (CBF) regulation at rest and even during steady-state exercise. At the onset of cycling exercise, Q increases acutely and largely via muscle pump. The purpose of the present study was to examine whether onset exercise-induced a large increase in Q contributes to CBF regulation at the onset of exercise. METHODS: In 20 young healthy participants (10 males and 10 females), Q, mean arterial pressure (MAP), and mean blood velocities of middle and posterior cerebral arteries (MCA Vm and PCA Vm) were continuously measured during light cycling exercise for 3 min. RESULTS: At the onset of exercise, Q increased acutely to the peak (P < 0.001), while the CBF peak responses were not significantly higher than the values during the steady-state exercise (MCA Vm and PCA Vm; P = 0.183 and P = 0.101, respectively). The change in Q was correlated with that of MCA Vm or PCA Vm from resting baseline to the steady-state exercise (r = 0.404, P < 0.001 and r = 0.393, P < 0.001, respectively). However, the change in Q was not correlated with that of MCA Vm or PCA Vm at the onset of exercise (P = 0.853 and P = 0.893, respectively). Any sex differences in the onset response of peripheral and cerebral hemodynamics to exercise were not observed. CONCLUSION: These findings suggest that the acute change in Q does not contribute to CBF regulation at the onset of exercise for protecting cerebral vasculature against a large and acute elevation in Q at the onset of exercise.
PURPOSE: Change in cardiac output (Q) contributes to cerebral blood flow (CBF) regulation at rest and even during steady-state exercise. At the onset of cycling exercise, Q increases acutely and largely via muscle pump. The purpose of the present study was to examine whether onset exercise-induced a large increase in Q contributes to CBF regulation at the onset of exercise. METHODS: In 20 young healthy participants (10 males and 10 females), Q, mean arterial pressure (MAP), and mean blood velocities of middle and posterior cerebral arteries (MCA Vm and PCA Vm) were continuously measured during light cycling exercise for 3 min. RESULTS: At the onset of exercise, Q increased acutely to the peak (P < 0.001), while the CBF peak responses were not significantly higher than the values during the steady-state exercise (MCA Vm and PCA Vm; P = 0.183 and P = 0.101, respectively). The change in Q was correlated with that of MCA Vm or PCA Vm from resting baseline to the steady-state exercise (r = 0.404, P < 0.001 and r = 0.393, P < 0.001, respectively). However, the change in Q was not correlated with that of MCA Vm or PCA Vm at the onset of exercise (P = 0.853 and P = 0.893, respectively). Any sex differences in the onset response of peripheral and cerebral hemodynamics to exercise were not observed. CONCLUSION: These findings suggest that the acute change in Q does not contribute to CBF regulation at the onset of exercise for protecting cerebral vasculature against a large and acute elevation in Q at the onset of exercise.
Authors: Thales C Barbosa; Igor A Fernandes; Nisval Magalhães; Ismar L Cavalcanti; Niels H Secher; Antonio C L Nóbrega; Lauro C Vianna Journal: Exp Physiol Date: 2015-02-09 Impact factor: 2.969
Authors: Sandra A Billinger; Jesse C Craig; Sarah J Kwapiszeski; Jason-Flor V Sisante; Eric D Vidoni; Rebecca Maletsky; David C Poole Journal: J Appl Physiol (1985) Date: 2017-03-09