The cerebrovasculature is more efficient at compensating for pharmacologically induced transient hypertension versus transient hypotension. Whether this phenomenon exists during non-pharmacologically hypertension and hypotension is currently unknown. We compared the % change in mean velocity in the middle cerebral artery (MCAvmean), per % change in mean arterial pressure (MAP) (%MCAVmean/%MAP) during transient hypertension and hypotension induced during squat-stand manoeuvres performed at 0.05 (20 second cycles) and 0.10 (10 second cycles) Hz in 58 male volunteers. The %MCAvmean/%MAP was attenuated by 25% (p=0.03; 0.05 Hz) and 47% (p<0.0001; 0.10 Hz) during transient hypertension vs. hypotension. Thus, these findings indicate the brain in healthy men is better adapted to compensate for physiologically relevant transient hypertension than hypotension.
- Cerebral blood flow
- Copyright © 2016, American Journal of Physiology-Heart and Circulatory Physiology