Abstract
This study was designed to determine the histological and metabolic effects of the administration of 5'-AMP-activated protein kinase (AMPK) activator 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) for 14 successive days. AICAR treatment caused a significant decrease in the percentage of type IIB fibers and the concomitant increase in the percentage of type IIX fibers in extensor digitorum longus (EDL) muscle. The capillary density and the capillary-to-fiber ratio were not altered by AICAR. AICAR treatment increased the glycolytic and oxidative enzyme activities but not the antioxidant enzyme activities. The AICAR treatment increased the uncoupling protein 3 (UCP3) level in EDL and the peroxisome proliferator-activated receptor-gamma coactivator-1alpha protein level in the soleus and EDL muscles, whereas the myogenin level was not altered by AICAR. These results seem to imply that the chronic activation of AMPK alters such muscle histochemical and metabolic characteristics.
MeSH terms
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AMP-Activated Protein Kinases
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Adipose Tissue / drug effects
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Adipose Tissue / physiology
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Aminoimidazole Carboxamide / analogs & derivatives*
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Aminoimidazole Carboxamide / pharmacology*
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Animals
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Antioxidants / metabolism
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Blotting, Western
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Body Composition / drug effects
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Body Composition / physiology
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Body Weight / drug effects
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Capillaries / drug effects
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Carrier Proteins / metabolism*
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Electrophoresis, Polyacrylamide Gel
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Enzyme Activators / pharmacology*
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Immunohistochemistry
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Ion Channels
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Male
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Mitochondrial Proteins
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Multienzyme Complexes / metabolism*
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Muscle Fibers, Skeletal / drug effects*
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Muscle, Skeletal / cytology
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Muscle, Skeletal / drug effects*
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Muscle, Skeletal / enzymology
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Physical Conditioning, Animal / physiology
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Protein Serine-Threonine Kinases / metabolism*
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Rats
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Rats, Wistar
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Ribonucleotides / pharmacology*
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Transcription Factors / metabolism*
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Uncoupling Protein 3
Substances
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Antioxidants
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Carrier Proteins
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Enzyme Activators
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Ion Channels
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Mitochondrial Proteins
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Multienzyme Complexes
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Ribonucleotides
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Transcription Factors
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Ucp3 protein, rat
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Uncoupling Protein 3
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peroxisome-proliferator-activated receptor-gamma coactivator-1
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Aminoimidazole Carboxamide
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Protein Serine-Threonine Kinases
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AMP-Activated Protein Kinases
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AICA ribonucleotide