| Myocardial substrate metabolism influences left ventricular energetics in vivo. | |
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MedLine Citation:
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PMID: 10749732 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The myocardial oxygen consumption (MVO(2)) to left ventricular pressure-volume area (PVA) relationship is assumed unaltered by substrates, despite varying phosphate-to-oxygen ratios and possible excess MVO(2) associated with fatty acid consumption. The validity of this assumption was tested in vivo. Left ventricular volumes and pressures were assessed with a combined conductance-pressure catheter in eight anesthetized pigs. MVO(2) was calculated from coronary flow and arterial-coronary sinus O(2) differences. Metabolism was altered by glucose-insulin-potassium (GIK) or Intralipid-heparin (IH) infusions in random order and monitored with [(14)C]glucose and [(3)H]oleate tracers. Profound shifts in glucose and fatty acid oxidation were observed. Contractility, coronary flow, and slope of the MVO(2)-PVA relationship were unchanged during GIK and IH infusions. MVO(2) at zero PVA (unloaded MVO(2)) was 0.16 +/- 0.13 J x beat(-1) x 100 g(-1) higher during IH compared with GIK infusion (P = 0.001), a 48% increase. The study demonstrates a marked energetic advantage of glucose oxidation in the myocardium, profoundly affecting the MVO(2)-PVA relationship. This may in part explain the "oxygen-wasting" effect of lipid-enhancing interventions such as adrenergic drugs and ischemia. |
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Authors:
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C Korvald; O P Elvenes; T Myrmel |
Publication Detail:
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Type: 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: 278 ISSN: 0363-6135 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2000 Apr |
Date Detail:
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Created Date: 2000-04-27 Completed Date: 2000-04-27 Revised Date: 2008-11-21 |
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: H1345-51 Citation Subset: IM |
Affiliation:
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Department of Thoracic and Cardiovascular Surgery, University Hospital in Tromsø, N-9038 Tromsø, Norway. korvald@fagmed.uit.no |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adenosine Triphosphate
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metabolism Animals Anticoagulants / pharmacology Carbon Radioisotopes / diagnostic use Cardiac Volume / physiology* Energy Metabolism / drug effects, physiology* Fat Emulsions, Intravenous / pharmacology Fatty Acids, Nonesterified / metabolism Glucose / metabolism, pharmacology Heart Ventricles / metabolism Heparin / pharmacology Insulin / metabolism, pharmacology Male Muscle Fibers, Skeletal / metabolism Myocardial Contraction / drug effects, physiology Myocardium / cytology, metabolism* Oxygen Consumption / physiology* Potassium / metabolism, pharmacology Swine |
| Chemical | |
Reg. No./Substance:
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0/Anticoagulants; 0/Carbon Radioisotopes; 0/Fat Emulsions, Intravenous; 0/Fatty Acids, Nonesterified; 11061-68-0/Insulin; 50-99-7/Glucose; 56-65-5/Adenosine Triphosphate; 7440-09-7/Potassium; 9005-49-6/Heparin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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