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Diminished baroreflex-induced vasoconstriction following alpha-2 adrenergic receptor blockade in humans.
- Source :
-
Autonomic neuroscience : basic & clinical [Auton Neurosci] 2008 Feb 29; Vol. 138 (1-2), pp. 114-7. Date of Electronic Publication: 2007 Dec 04. - Publication Year :
- 2008
-
Abstract
- The relative contribution of alpha adrenergic receptor subtypes in the transduction of sympathetic nerve activity (SNA) during carotid baroreflex (CBR) engagement is not well understood. Therefore, we compared the hemodynamic consequence of CBR-mediated sympatho-excitation via neck pressure (NP) before and after alpha-2 adrenergic blockade with intra-arterial yohimbine. Leg blood flow was measured using 2D and Doppler ultrasound, and arterial blood pressure was determined directly. NP caused the expected vasoconstriction, and this response was significantly reduced (by 50-60%) when NP was repeated after yohimbine. These data indicate that alpha-2 adrenergic receptors contribute significantly to CBR-induced vasoconstriction in the human leg under resting conditions.
- Subjects :
- Adrenergic alpha-Antagonists pharmacology
Adult
Baroreflex drug effects
Blood Pressure drug effects
Blood Pressure physiology
Carotid Sinus drug effects
Femoral Artery diagnostic imaging
Femoral Artery innervation
Humans
Leg blood supply
Leg physiology
Male
Pressoreceptors drug effects
Pressoreceptors physiology
Receptors, Adrenergic, alpha-2 metabolism
Regional Blood Flow drug effects
Regional Blood Flow physiology
Sympathetic Fibers, Postganglionic drug effects
Ultrasonography, Doppler, Color
Vasoconstriction drug effects
Yohimbine pharmacology
Adrenergic alpha-2 Receptor Antagonists
Baroreflex physiology
Carotid Sinus physiology
Femoral Artery physiology
Sympathetic Fibers, Postganglionic physiology
Vasoconstriction physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1566-0702
- Volume :
- 138
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Autonomic neuroscience : basic & clinical
- Publication Type :
- Academic Journal
- Accession number :
- 18054844
- Full Text :
- https://doi.org/10.1016/j.autneu.2007.11.002