| Downregulation of ventricular contractile function during early ischemia is flow but not pressure dependent. | |
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MedLine Citation:
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PMID: 9815056 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The mechanism responsible for the abrupt fall in myocardial contractile function following coronary artery obstruction is unknown. The "vascular collapse theory" hypothesizes that the fall in coronary perfusion pressure after coronary artery obstruction is responsible for contractile failure during early ischemia. To test the role of vascular collapse in downregulating myocardial contractile force at the onset of ischemia, coronary flow of isolated rat hearts was abruptly decreased by 50, 70, 85, and 100% of baseline, and subsequent changes in coronary perfusion pressure and ventricular function were recorded at 0.5-s intervals. At 1.5 s after flow reductions ranging from 50 to 100%, decreases in contractile function did not differ, although perfusion pressure varied significantly from 45 +/- 1 to 20 +/- 2 mmHg. When function fell to 50% of baseline, perfusion pressures ranged from 35 +/- 0.5 to 2.5 +/- 1 mmHg for flow reductions ranging from 50 to 100%. Identical contractile function at widely differing coronary perfusion pressures is incompatible with the vascular collapse theory. |
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Authors:
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M X He; H F Downey |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The American journal of physiology Volume: 275 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1998 Nov |
Date Detail:
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Created Date: 1998-12-10 Completed Date: 1998-12-10 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: H1520-3 Citation Subset: IM |
Affiliation:
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Department of Integrative Physiology, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas 76107-2699, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure Coronary Circulation / physiology* Down-Regulation Heart Ventricles / physiopathology* Myocardial Contraction / physiology* Myocardial Ischemia / blood, physiopathology* Rats |
| Grant Support | |
ID/Acronym/Agency:
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HL-35027/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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