Abstract
We compared UCP3 protein in rat cardiac, glycolytic and oxidative skeletal muscle and examined the effect of high-fat medium chain vs. long chain triacylglycerol feeding on UCP3 content in these tissues. Cardiac muscle displays the lowest basal levels of UCP3 protein. Increasing long chain - but not medium chain - fatty acid supply upregulates UCP3 in all muscles. Since plasma non-esterified fatty acids and the expression of two peroxisome proliferator-activated receptor (PPAR)-responsive genes, were not different between groups, we conclude that the differential upregulation of UCP3 is not merely PPAR-mediated. This study supports a role of UCP3 in export of non-metabolizable fatty acids.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptation, Physiological / drug effects
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Adaptation, Physiological / physiology
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Animal Nutritional Physiological Phenomena
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Animals
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Body Weight / drug effects
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Body Weight / physiology
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Carrier Proteins / biosynthesis*
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Energy Intake / drug effects
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Energy Intake / physiology
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Ion Channels
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Male
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Mitochondrial Proteins
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Muscle, Skeletal / metabolism
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Myocardium / metabolism
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RNA, Messenger / analysis
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RNA, Messenger / biosynthesis
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Rats
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Rats, Wistar
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Receptors, Cytoplasmic and Nuclear / genetics
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Receptors, Cytoplasmic and Nuclear / metabolism
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Transcription Factors / genetics
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Transcription Factors / metabolism
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Triglycerides / chemistry
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Triglycerides / metabolism*
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Triglycerides / pharmacology
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Uncoupling Protein 3
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Up-Regulation
Substances
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Carrier Proteins
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Ion Channels
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Mitochondrial Proteins
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RNA, Messenger
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Receptors, Cytoplasmic and Nuclear
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Transcription Factors
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Triglycerides
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UCP3 protein, human
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Ucp3 protein, rat
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Uncoupling Protein 3