Abstract
Aim: Sympathetic regulation of the cerebral circulation remains controversial. Although intravenous phenylephrine (PE) infusion reduces the near-infrared spectroscopy (NIRS)-determined measure of frontal lobe oxygenation (ScO2) and increases middle cerebral artery mean blood velocity (MCA V-mean), suggesting alpha-adrenergic-mediated cerebral vasoconstriction, this remains unconfirmed by evaluation of arterial and venous cerebral blood flow.
Methods: We determined ScO2, MCA V-mean, and right internal carotid artery (ICA) and internal jugular venous (IJV) blood flow (duplex ultrasound) during infusion of PE in eight supine young healthy men [26 (3) years, 177 (7) cm and 74 (8) kg; mean (SD)].
Results: Compared with saline, during infusion of PE, mean arterial pressure increased 26 +/- 3% (mean +/- SE) and MCA Vmean by 4.8 +/- 1.9% (P
Original language | English |
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Pages (from-to) | 445-451 |
Number of pages | 7 |
Journal | Clinical physiology and functional imaging |
Volume | 31 |
Issue number | 6 |
DOIs | |
Publication status | Published - 1 Nov 2011 |
Keywords
- near-infrared spectroscopy
- internal jugular venous
- middle cerebral artery mean blood velocity
- frontal lobe oxygenation
- sympathetic nerve activity
- internal carotid artery