Pyruvate dehydrogenase activation and kinase expression in human skeletal muscle during fasting

Spriet, Lawrence L., Tunstall, Rebecca J., Watt, Matthew J., Mehan, Kate A., Hargreaves, Mark and Cameron-Smith, David 2004, Pyruvate dehydrogenase activation and kinase expression in human skeletal muscle during fasting, Journal of applied physiology, vol. 96, pp. 2082-2087.

Attached Files
Name Description MIMEType Size Downloads

Title Pyruvate dehydrogenase activation and kinase expression in human skeletal muscle during fasting
Author(s) Spriet, Lawrence L.
Tunstall, Rebecca J.
Watt, Matthew J.
Mehan, Kate A.
Hargreaves, Mark
Cameron-Smith, David
Journal name Journal of applied physiology
Volume number 96
Start page 2082
End page 2087
Publisher American Physiological Society
Place of publication Bethesda, Md.
Publication date 2004-02-13
ISSN 8750-7587
1522-1601
Keyword(s) carbohydrate oxidation
fat oxidation
peroxisome proliferation-activated receptors
pyruvate dehydrogenase kinase isozymes
forkhead homolog in rhabdomyosarcoma
mRNA
Summary Fasting forces adaptive changes in whole body and skeletal muscle metabolism that increase fat oxidation and decrease the oxidation of carbohydrate. We tested the hypothesis that 40 h of fasting would decrease pyruvate dehydrogenase (PDH) activity and increase PDH kinase (PDK) isoform mRNA expression in human skeletal muscle. The putative transcriptional activators of PDK isozymes, peroxisome proliferator-activated receptor-α (PPAR-α) protein, and forkhead homolog in rhabdomyosarcoma (FKHR) mRNA were also measured. Eleven healthy adults fasted after a standard meal (25% fat, 60% carbohydrate, 15% protein) with blood and skeletal muscle samples taken at 3, 15, and 40 h postprandial. Fasting increased plasma free fatty acid, glycerol, and β-hydroxybutyrate concentrations and decreased glucose and insulin concentrations. PDH activity decreased from 0.88 ± 0.11 mmol acetyl-CoA · min-1 · kg wet muscle wt-1 at 3 h to 0.62 ± 0.10 (P = not significant) and 0.39 ± 0.06 (P < 0.05) mmol · min-1 · kg wet mass-1 after 15 and 40 h of fasting. Although all four PDK isoforms were expressed in human skeletal muscle, PDK-2 and -4 mRNA were the most abundant. PDK-1 and -3 mRNA abundance was ~1 and 15% of the PDK-2 and 4- levels, respectively. The 40-h fast had no effect on PDK-1, -2, and -3 mRNA expression. PDK-4 mRNA was significantly increased ~3-fold after 15 h and ~14-fold after 40 h of fasting. Skeletal muscle PPAR-α protein and FKHR mRNA abundance were unaffected by the fast. The results suggest that decreased PDH activation after 40 h of fasting may have been a function of the large increase in PDK-4 mRNA expression and possible subsequent increase in PDK protein and activity. The changes in PDK-4 expression and PDH activity did not coincide with increases in the transcriptional activators PPAR-α and FKHR.
Language eng
Field of Research 060104 Cell Metabolism
HERDC Research category C1 Refereed article in a scholarly journal
Copyright notice ©2004, American Physiological Society
Persistent URL http://hdl.handle.net/10536/DRO/DU:30008681

Document type: Journal Article
Collection: School of Exercise and Nutrition Sciences
Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 39 times in TR Web of Science
Scopus Citation Count Cited 38 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 442 Abstract Views, 0 File Downloads  -  Detailed Statistics
Created: Mon, 13 Oct 2008, 15:38:56 EST

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.