| Autor: |
Yu-Chieh Tzeng, Gregory S. H. Chan, Christopher K. Willie, Philip N. Ainslie |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
The Journal of Physiology. 589:3263-3274 |
| ISSN: |
0022-3751 |
| DOI: |
10.1113/jphysiol.2011.206953 |
| Popis: |
Non-technical summary Brain function is critically dependent on the regulation of cerebral blood flow (CBF) by cerebral blood vessels. We show that a mechanical blood vessel property called compliance plays an important role in determining the way cerebral blood vessels respond to changes in blood pressure. These results enhance our knowledge of how cerebral blood vessels regulate CBF, which is critical to understanding the causes and effects of cerebrovascular diseases such as stroke and dementia. Abstract The fundamental determinants of human dynamic cerebral autoregulation are poorly understood, particularly the role of vascular compliance and the myogenic response. We sought to 1) determine whether capacitive blood flow associated with vascular compliance and driven by the rate of change in mean arterial blood pressure (dMAP/dt )i s an important determinant of middle cerebral artery velocity (MCAv) dynamics and 2) characterise the impact of myogenic blockade on these cerebral pressure-flow velocity relations in humans. We measured MCAv and mean arterial pressure (MAP) during oscillatory lower body negative pressure (n =8) at 0.10 and 0.05 Hz before and after cerebral Ca 2+ channel blockade (nimodipine). Pressure-flow velocity relationships were characterised using transfer function analysis and a regression-based Windkessel analysis that incorporates MAP and dMAP/dt as predictors of MCAv dynamics. Results show that incorporation of dMAP/dt accounted for more MCAv variance (R 2 0.80-0.99) thanifonlyMAPwasconsidered(R 2 0.05-0.90).ThecapacitivegainrelatingdMAP/dt andMCAv was strongly correlated to transfer function gain (0.05 Hz, r =0.93, P |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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