| Skeletal muscle pyruvate dehydrogenase activity during acetate infusion in humans. | |
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MedLine Citation:
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PMID: 7762627 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Pyruvate dehydrogenase activity (PDHa), acetyl group, and citrate accumulation were examined in human skeletal muscle at rest and during cycling exercise while acetate was infused. Eight subjects received 400 mmol of sodium acetate (Ace) at a constant rate during 20 min of rest, 5 min of cycling at 40% maximal O2 uptake (VO2max) and 15 min of cycling at 80% VO2max. Two weeks later experiments were repeated while 400 mmol of sodium bicarbonate was infused in the control condition (CON). Ace infusion increased muscle acetyl-coenzyme A (acetyl-CoA), citrate, and acetylcarnitine. A decline in resting PDHa during 20 min of Ace infusion (0.37 +/- 0.08 vs. 0.16 +/- 0.03 mmol.min-1.kg wet wt-1) coincided with an elevation in the acetyl-CoA-to-free CoA ratio (acetyl-CoA/CoASH; 0.28 +/- 0.04 to 0.73 +/- 0.14). After 20 min of CON infusion, resting PDHa (0.32 +/- 0.06 mmol.min-1.kg wet wt-1) was similar to PDHa before Ace infusion. During exercise, acetyl-CoA, citrate, and acetyl-CoA/CoASH were further elevated, and the differences that existed at rest were resolved. PDHa increased to the same extent in Ace and CON, in which it was 44-47% transformed after 5 min at 40% VO2max and completely transformed after 15 min at 80% VO2max. At rest PDHa was regulated by variations in acetyl-CoA/CoASH secondary to enhanced acetate metabolism. Conversely, during exercise PDHa regulation appeared independent of variations in acetyl-CoA/CoASH. The resting data are consistent with a central role for PDHa and citrate in the regulation of the glucose-fatty acid cycle in skeletal muscle, as classically proposed. However, in the present study Ace infusion was not effective in perturbing the glucose-fatty acid cycle during exercise. |
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Authors:
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C T Putman; L L Spriet; E Hultman; D J Dyck; G J Heigenhauser |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The American journal of physiology Volume: 268 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1995 May |
Date Detail:
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Created Date: 1995-06-29 Completed Date: 1995-06-29 Revised Date: 2006-11-15 |
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: E1007-17 Citation Subset: IM |
Affiliation:
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Department of Medicine, McMaster University Medical Centre, Hamilton, Ontario, Canada. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Acetates
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blood,
pharmacology* Acetyl Coenzyme A / metabolism Adult Blood / metabolism Coenzyme A / metabolism Female Humans Hydrogen-Ion Concentration Infusions, Intravenous Male Muscle, Skeletal / metabolism* Oxygen Consumption Pyruvate Dehydrogenase Complex / metabolism* |
| Chemical | |
Reg. No./Substance:
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0/Acetates; 0/Pyruvate Dehydrogenase Complex; 72-89-9/Acetyl Coenzyme A; 85-61-0/Coenzyme A |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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