| Stenosis differentially affects subendocardial and subepicardial arterioles in vivo. | |
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MedLine Citation:
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PMID: 11247779 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The presence of a coronary stenosis results primarily in subendocardial ischemia. Apart from the decrease in coronary perfusion pressure, a stenosis also decreases coronary flow pulsations. Applying a coronary perfusion system, we compared the autoregulatory response of subendocardial (n = 10) and subepicardial (n = 12) arterioles (<120 microm) after stepwise decreases in coronary arterial pressure from 100 to 70, 50, and 30 mmHg in vivo in dogs (n = 9). Pressure steps were performed with and without stenosis on the perfusion line. Maximal arteriolar diameter during the cardiac cycle was determined and normalized to its value at 100 mmHg. The initial decrease in diameter during reductions in pressure was significantly larger at the subendocardium. Diameters of subendocardial and subepicardial arterioles were similar 10--15 s after the decrease in pressure without stenosis. However, stenosis decreased the dilatory response of the subendocardial arterioles significantly. This decreased dilatory response was also evidenced by a lower coronary inflow at similar average pressure in the presence of a stenosis. Inhibition of nitric oxide production with N(G)-monomethyl-L-arginine abrogated the effect of the stenosis on flow. We conclude that the decrease in pressure caused by a stenosis in vivo results in a larger decrease in diameter of the subendocardial arterioles than in the subepicardial arterioles, and furthermore stenosis selectively decreases the dilatory response of subendocardial arterioles. These two findings expand our understanding of subendocardial vulnerability to ischemia. |
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Authors:
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D Merkus; I Vergroesen; O Hiramatsu; H Tachibana; H Nakamoto; E Toyota; M Goto; Y Ogasawara; J A Spaan; F Kajiya |
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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: American journal of physiology. Heart and circulatory physiology Volume: 280 ISSN: 0363-6135 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2001 Apr |
Date Detail:
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Created Date: 2001-03-15 Completed Date: 2001-04-19 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: United States |
Other Details:
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Languages: eng Pagination: H1674-82 Citation Subset: IM |
Affiliation:
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Department of Medical Physics, Cardiovascular Research Institute Amsterdam, Academic Medical Center, University of Amsterdam, 1100 DE Amsterdam, The Netherlands. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Arterioles / drug effects, physiology, physiopathology* Blood Pressure Coronary Circulation / drug effects, physiology* Coronary Disease / physiopathology* Dogs Endocardium / physiology, physiopathology* Heart / physiology, physiopathology* Heart Rate Hemodynamics / drug effects, physiology* Homeostasis Microscopy, Video Pacemaker, Artificial Pericardium / physiology, physiopathology* Reference Values Vascular Resistance omega-N-Methylarginine / pharmacology* |
| Chemical | |
Reg. No./Substance:
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17035-90-4/omega-N-Methylarginine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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