| Flow-mediated dilatation following wrist and upper arm occlusion in humans: the contribution of nitric oxide. | |
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MedLine Citation:
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PMID: 11724650 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Flow-mediated dilatation (FMD) of the brachial artery assessed by high-resolution ultrasound is widely used to measure endothelial function. However, the technique is not standardized, with different groups using occlusion of either the wrist or the upper arm to induce increased blood flow. The validity of the test as a marker of endothelial function rests on the assumption that the dilatation observed is endothelium-dependent and mediated by nitric oxide (NO). We sought to compare the NO component of brachial artery dilatation observed following wrist or upper arm occlusion. Dilatation was assessed before and during intra-arterial infusion of the NO synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) following occlusion of (i) the wrist (distal to ultrasound probe) and (ii) the upper arm (proximal to ultrasound probe) for 5 min in ten healthy males. Dilatation was significantly greater after upper arm occlusion (upper arm, 11.62+/-3.17%; wrist, 7.25+/-2.49%; P=0.003). During L-NMMA infusion, dilatation after wrist occlusion was abolished (from 7.25+/-2.49% to 0.16+/-2.24%; P<0.001), whereas dilatation after upper arm occlusion was only partially attenuated (from 11.62+/-3.17% to 7.51+/-2.34%; P=0.006). The peak flow stimulus was similar after wrist and upper arm occlusion. We conclude that dilatation following upper arm occlusion is greater than that observed after wrist occlusion, despite a similar peak flow stimulus. L-NMMA infusion revealed that FMD following wrist occlusion is mediated exclusively by NO, while dilatation following upper arm occlusion comprises a substantial component not mediated by NO, most probably related to tissue ischaemia around the brachial artery. FMD following wrist occlusion may be a more valid marker of endothelial function than dilatation following upper arm occlusion. |
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Authors:
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S N Doshi; K K Naka; N Payne; C J Jones; M Ashton; M J Lewis; J Goodfellow |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Clinical science (London, England : 1979) Volume: 101 ISSN: 0143-5221 ISO Abbreviation: Clin. Sci. Publication Date: 2001 Dec |
Date Detail:
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Created Date: 2001-11-28 Completed Date: 2002-01-07 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7905731 Medline TA: Clin Sci (Lond) Country: England |
Other Details:
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Languages: eng Pagination: 629-35 Citation Subset: IM |
Affiliation:
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Department of Pharmacology, Cardiovascular Sciences Research Group, Wales Heart Research Institute, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, UK. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Arm / blood supply* Brachial Artery / physiology Constriction Dose-Response Relationship, Drug Endothelium, Vascular / physiology* Enzyme Inhibitors / pharmacology Humans Male Nitric Oxide / physiology* Nitric Oxide Synthase / antagonists & inhibitors, physiology Reproducibility of Results Vasodilation / physiology* Wrist / blood supply omega-N-Methylarginine / pharmacology |
| Chemical | |
Reg. No./Substance:
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0/Enzyme Inhibitors; 10102-43-9/Nitric Oxide; 17035-90-4/omega-N-Methylarginine; EC 1.14.13.39/Nitric Oxide Synthase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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