| Flow-mediated dilation of the radial artery is offset by flow-induced reduction in transmural pressure. | |
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MedLine Citation:
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PMID: 21502570 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Flow-mediated dilation of the brachial or radial artery in response to transient hyperaemic flow, the most widely used test of endothelial function, is only manifest after flow decays back to baseline. We examined whether this dissociation of flow and diameter might be explained by a reduction in transmural pressure generated by high flow. Studies were performed in healthy subjects 20 to 55 years of age. Flow-mediated dilation was measured in the radial artery using a standard protocol and after flow interruption at peak hyperemia during brachial artery infusion of saline and the NO synthase inhibitor N(G)-monomethyl-L-arginine (8 μmol/min). Flow interruption 20 seconds after cuff release (during high flow but no dilatation) produced an immediate increase in radial artery diameter of 5.36±2.12%, inhibited by N(G)-monomethyl-L-arginine to 1.09±0.67% (n=8; P<0.001). Mean intra-arterial radial blood pressure and, hence, transmural pressure fell after cuff release by a mean of 26±1.8 mm Hg (n=6; P<0.0001) at the time of peak hyperemic flow. Modulation of transmural pressure within the brachial artery by cuff inflation around the artery demonstrated that this fall is sufficient to reduce arterial diameter by an amount similar to flow-mediated dilation. These results suggest that flow-dependent, NO-dependent dilation is offset by a flow-induced fall in local arterial pressure and, hence, in transmural pressure. Shear related NO release is likely to play a greater role in the short-term regulation of arterial tone than that suggested by flow-mediated dilation. |
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Authors:
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Benyu Jiang; Mike Seddon; Henry Fok; Ann Donald; Phil Chowienczyk |
Publication Detail:
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Type: Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't Date: 2011-04-18 |
Journal Detail:
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Title: Hypertension Volume: 57 ISSN: 1524-4563 ISO Abbreviation: Hypertension Publication Date: 2011 Jun |
Date Detail:
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Created Date: 2011-05-19 Completed Date: 2011-07-22 Revised Date: 2011-10-21 |
Medline Journal Info:
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Nlm Unique ID: 7906255 Medline TA: Hypertension Country: United States |
Other Details:
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Languages: eng Pagination: 1145-50 Citation Subset: IM |
Affiliation:
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King's College London, British Heart Foundation Centre, London, United Kingdom. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adrenergic alpha-Antagonists
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pharmacology Adult Analysis of Variance Blood Pressure / drug effects, physiology* Brachial Artery / drug effects, physiology Endothelium, Vascular / drug effects, metabolism, physiology* Enzyme Inhibitors / pharmacology Humans Hyperemia / physiopathology Male Middle Aged Nitric Oxide / metabolism Nitric Oxide Synthase / antagonists & inhibitors, metabolism Phentolamine / pharmacology Radial Artery / drug effects, physiology* Vasodilation / drug effects, physiology* Young Adult omega-N-Methylarginine / pharmacology |
| Grant Support | |
ID/Acronym/Agency:
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//British Heart Foundation |
| Chemical | |
Reg. No./Substance:
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0/Adrenergic alpha-Antagonists; 0/Enzyme Inhibitors; 10102-43-9/Nitric Oxide; 17035-90-4/omega-N-Methylarginine; 50-60-2/Phentolamine; EC 1.14.13.39/Nitric Oxide Synthase |
| Comments/Corrections | |
Comment In:
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Hypertension. 2011 Jun;57(6):1049-50
[PMID:
21502565
]
Hypertension. 2011 Oct;58(4):e21; author reply e22 [PMID: 21844491 ] |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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