We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow, in healthy subjects, during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior blood flow, were continuously measured during an exercise trial, using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level. During both static and dynamic exercise, the PCA cerebrovascular conductance (CVC) index significantly decreased from rest (static and high intensity dynamic exercise; −11.5 ± 12.2% and −18.0 ± 16.8%; mean ± SD, respectively), despite no change in the CVC of VA. These results indicate that vasoconstriction occurred at PCA but not VA during exercise-induced hypertension. This discrepancy in vascular response to exercise between PCA and VA may be due to different cerebral arterial characteristics. Therefore, to determine the effect of exercise on posterior cerebral circulation, at least, we need to consider carefully which cerebral artery to measure, regardless of exercise mode.
- osterior cerebral circulation
- vertebral artery
- cerebral blood flow velocity
- Transcranial Doppler ultrasonography
- Copyright © 2016, American Journal of Physiology-Heart and Circulatory Physiology