Dystrophin-dependent efficiency of metabolic pathways in mouse skeletal muscles.
Muscles from the mdx mouse (X-linked genetic disorder similar to Duchenne muscular dystrophy) lack dystrophin-associated transsarcolemmal proteins and show reduced maintenance metabolic rates. Here, microcalorimetric comparisons of metabolic stimulation by exogenous substrates in isolated muscles revealed substrate-selective limitation of chemical reaction rates through both glycolytic and TCA-cycle pathways, identical in slow- and fast-twitch mdx muscles. This systemic approach, as opposed to comparisons of single-enzyme activities, sheds new light on the function of dystrophin and associated proteins. The in vivo efficiency of metabolic pathways may depend on stabilization of enzyme complexes by dystrophin-associated elements of the cytoskeleton.
Département de Physiologie, Centre Médical Universitaire, Geneva, Switzerland.
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Chinet
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Even
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Decrouy
D000818:Animals; D002952:Citric Acid Cycle; D003599:Cytoskeleton / Q000378:metabolism; D016189:Dystrophin / Q000502:physiology*; D004734:Energy Metabolism; D006019:Glycolysis; D051379:Mice; D008817:Mice, Mutant Strains; D009132:Muscles / Q000378:metabolism*; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*
D016189:Dystrophin