Document Detail


Chronic AMP-activated protein kinase activation and a high-fat diet have an additive effect on mitochondria in rat skeletal muscle.
MedLine Citation:
PMID:  20522731     Owner:  NLM     Status:  In-Process    
Abstract/OtherAbstract:
Factors that stimulate mitochondrial biogenesis in skeletal muscle include AMP-activated protein kinase (AMPK), calcium, and circulating free fatty acids (FFAs). Chronic treatment with either 5-aminoimidazole-4-carboxamide riboside (AICAR), a chemical activator of AMPK, or increasing circulating FFAs with a high-fat diet increases mitochondria in rat skeletal muscle. The purpose of this study was to determine whether the combination of chronic chemical activation of AMPK and high-fat feeding would have an additive effect on skeletal muscle mitochondria levels. We treated Wistar male rats with a high-fat diet (HF), AICAR injections (AICAR), or a high-fat diet and AICAR injections (HF + AICAR) for 6 wk. At the end of the treatment period, markers of mitochondrial content were examined in white quadriceps, red quadriceps, and soleus muscles, predominantly composed of unique muscle-fiber types. In white quadriceps, there was a cumulative effect of treatments on long-chain acyl-CoA dehydrogenase, cytochrome c, and peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) protein, as well as on citrate synthase and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activity. In contrast, no additive effect was noted in the soleus, and in the red quadriceps only beta-HAD activity increased additively. The additive increase of mitochondrial markers observed in the white quadriceps may be explained by a combined effect of two separate mechanisms: high-fat diet-induced posttranscriptional increase in PGC-1alpha protein and AMPK-mediated increase in PGC-1alpha protein via a transcriptional mechanism. These data show that chronic chemical activation of AMPK and a high-fat diet have a muscle type specific additive effect on markers of fatty acid oxidation, the citric acid cycle, the electron transport chain, and transcriptional regulation.
Authors:
Natasha Fillmore; Daniel L Jacobs; David B Mills; William W Winder; Chad R Hancock
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural     Date:  2010-06-03
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  109     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-08-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  511-20     Citation Subset:  IM    
Affiliation:
Department of Physiology and Developmental Biology, Birgham Young University, Provo, UT 84602, USA.
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MeSH Terms
Descriptor/Qualifier:
Grant Support
ID/Acronym/Agency:
AR-051928/AR/NIAMS NIH HHS

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