title: [Muscle, fatigue, sports and infection].
abstract: OBJECTIVE
  Skeletal muscle can be considered as motors which convert chemical energy into mechanical energy. We can evaluate the intracellular pH and energy state of phosphate-containing metabolites in skeletal muscle of patients complaining fatigue or asthenia, using phosphorus MRS.
  
  
  RESULTS
  Acute infectious disease and extreme endurance exercise may induce a loss of oxidative capacity of muscle tissue. Muscle fatigue is not due only to an insufficient supply of ATP to the energy consuming mechanisms. Phosphorus MRS show a muscle production of toxic metabolites such as lactates, protons and ammonia. These metabolic features induced excessive intracellular acidosis of skeletal muscle and systemic hyperammonia, responsible of fatigue and asthenia.
  
  
  CONCLUSIONS
  Reversal of the excessive acidosis and improvement of the capacity for oxidative ATP synthesis might help to relieve the symptoms of exhaustion/fatigue in these patients.
authors.affiliation: Service de médecine interne, CHU Pitié-Salpêtrière, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Chérin
mesh_terms: D000818:Animals; D001247:Asthenia / Q000209:etiology* / Q000503:physiopathology; D004576:Electromyography; D015444:Exercise / Q000502:physiology; D006801:Humans; D007239:Infections / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D017240:Mitochondrial Myopathies / Q000378:metabolism / Q000503:physiopathology; D018763:Muscle Fatigue / Q000502:physiology; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology* / Q000648:ultrastructure; D051381:Rats; D013177:Sports
chemical_list: D009124:Muscle Proteins