| Triidothyronine and epinephrine rapidly modify myocardial substrate selection: a (13)C isotopomer analysis. | |
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MedLine Citation:
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PMID: 11595654 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Triiodothyronine (T(3)) exerts direct action on myocardial oxygen consumption (MVO(2)), although its immediate effects on substrate metabolism have not been elucidated. The hypothesis, that T(3) regulates substrate selection and flux, was tested in isovolumic rat hearts under four conditions: control, T(3) (10 nM), epinephrine (Epi), and T(3) and Epi (TE). Hearts were perfused with [1,3-(13)C]acetoacetic acid (AA, 0.17 mM), L-[3-(13)C]lactic acid (LAC, 1.2 mM), U-(13)C-labeled long-chain free fatty acids (FFA, 0.35 mM), and unlabeled D-glucose (5.5 mM) for 30 min. Fractional acetyl-CoA contribution to the tricarboxylic acid cycle (Fc) per substrate was determined using (13)C NMR and isotopomer analysis. Oxidative fluxes were calculated using Fc, the respiratory quotient, and MVO(2). T(3) increased (P < 0.05) Fc(FFA), decreased Fc(LAC), and increased absolute FFA oxidation from 0.58 +/- 0.03 to 0.68 +/- 0.03 micromol. min(-1). g dry wt(-1) (P < 0.05). Epi decreased Fc(FFA) and Fc(AA), although FFA flux increased from 0.58 +/- 0.03 to 0.75 +/- 0.09 micromol. min(-1). g dry wt(-1). T(3) moderated the change in Fc(FFA) induced by Epi. In summary, T(3) exerts direct action on substrate pathways and enhances FFA selection and oxidation, although the Epi effect dominates at a high work state. |
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Authors:
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J J Krueger; X H Ning; B M Argo; O Hyyti; M A Portman |
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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: American journal of physiology. Endocrinology and metabolism Volume: 281 ISSN: 0193-1849 ISO Abbreviation: Am. J. Physiol. Endocrinol. Metab. Publication Date: 2001 Nov |
Date Detail:
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Created Date: 2001-10-11 Completed Date: 2001-12-04 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 100901226 Medline TA: Am J Physiol Endocrinol Metab Country: United States |
Other Details:
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Languages: eng Pagination: E983-90 Citation Subset: IM |
Affiliation:
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Division of Cardiology, Department of Pediatrics, University of Washington, School of Medicine, Seattle 98195, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acetoacetates
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administration & dosage,
metabolism Acetyl Coenzyme A / metabolism Animals Citric Acid Cycle Epinephrine / pharmacology* Fatty Acids, Nonesterified / administration & dosage, metabolism Glucose / administration & dosage, metabolism Heart / drug effects Lactic Acid / administration & dosage, metabolism Magnetic Resonance Spectroscopy Male Myocardium / metabolism* Oxygen Consumption / drug effects Rats Rats, Sprague-Dawley Triiodothyronine / pharmacology* Ventricular Function, Left / drug effects |
| Grant Support | |
ID/Acronym/Agency:
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R01-HL-60666/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Acetoacetates; 0/Fatty Acids, Nonesterified; 50-21-5/Lactic Acid; 50-99-7/Glucose; 51-43-4/Epinephrine; 541-50-4/acetoacetic acid; 6893-02-3/Triiodothyronine; 72-89-9/Acetyl Coenzyme A |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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