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Tissue-specific changes in fatty acid oxidation in hypoxic heart and skeletal muscle
Citation
Morash, AJ and Kotwica, AO and Murray, AJ, Tissue-specific changes in fatty acid oxidation in hypoxic heart and skeletal muscle, American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, 305, (5) pp. R534-R541. ISSN 0363-6119 (2014) [Refereed Article]
Copyright Statement
Copyright 2014 Amer Physiological Soc
DOI: doi:10.1152/ajpregu.00510.2012
Abstract
Exposure to hypobaric hypoxia is sufficient to decrease cardiac PCr/ATP and alters skeletal muscle energetics in humans. Cellular mechanisms underlying the different metabolic responses of these tissues and the time-dependent nature of these changes are currently unknown, but altered substrate utilization and mitochondrial function may be a contributory factor. We therefore sought to investigate the effects of acute (1 day) and more sustained (7 days) hypoxia (13% O2) on the transcription factor peroxisome proliferator-activated receptor α (PPARα) and its targets in mouse cardiac and skeletal muscle. In the heart, PPARα expression was 40% higher than in normoxia after 1 and 7 days of hypoxia. Activities of carnitine palmitoyltransferase (CPT) I and β-hydroxyacyl-CoA dehydrogenase (HOAD) were 75% and 35% lower, respectively, after 1 day of hypoxia, returning to normoxic levels after 7 days. Oxidative phosphorylation respiration rates using palmitoyl-carnitine followed a similar pattern, while respiration using pyruvate decreased. In skeletal muscle, PPARα expression and CPT I activity were 20% and 65% lower, respectively, after 1 day of hypoxia, remaining at this level after 7 days with no change in HOAD activity. Oxidative phosphorylation respiration rates using palmitoyl-carnitine were lower in skeletal muscle throughout hypoxia, while respiration using pyruvate remained unchanged. The rate of CO2 production from palmitate oxidation was significantly lower in both tissues throughout hypoxia. Thus cardiac muscle may remain reliant on fatty acids during sustained hypoxia, while skeletal muscle decreases fatty acid oxidation and maintains pyruvate oxidation.
Item Details
Item Type: | Refereed Article |
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Keywords: | fatty acids, heart, hypoxia, metabolism, mitochondrial respiration |
Research Division: | Biomedical and Clinical Sciences |
Research Group: | Medical biochemistry and metabolomics |
Research Field: | Metabolic medicine |
Objective Division: | Expanding Knowledge |
Objective Group: | Expanding knowledge |
Objective Field: | Expanding knowledge in the health sciences |
UTAS Author: | Morash, AJ (Dr Andrea Morash) |
ID Code: | 94194 |
Year Published: | 2014 |
Web of Science® Times Cited: | 22 |
Deposited By: | Research Division |
Deposited On: | 2014-09-02 |
Last Modified: | 2014-09-23 |
Downloads: | 0 |
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