title: 31P NMR spectroscopy and ergometer exercise test as evidence for muscle oxidative performance improvement with coenzyme Q in mitochondrial myopathies.
abstract: Two patients with mitochondrial encephalomyopathy due to complexes I and IV deficiencies received 150 mg/d of coenzyme Q10 (CoQ). We studied them with a bicycle ergometer exercise test and 31P NMR spectroscopy before and after 10 months of treatment. Before treatment, we observed a low phosphocreatine/inorganic phosphate (PCr/P(i)) resting value along with abnormally high resting lactate concentration. During exercise, there was a pronounced acidosis with delayed kinetics of postexercise recovery for blood lactate, pH, PCr, and PCr/P(i) ratio. Oxygen uptake during exercise was reduced while the lowering of the ventilatory threshold indicated an early activation of glycolysis. After treatment, the bicycle ergometer exercise test indicated a significant improvement with a decrease in resting blood lactate level, an increase in oxygen consumption during exercise, and an increase in the kinetics of lactate disappearance during the recovery period. A shift of the ventilatory threshold to higher workload was present. 31P NMR spectroscopy confirmed the improvement, showing a significant increase in the PCr/P(i) ratio at rest and in the kinetics of recovery for pH, PCr, and PCr/P(i) ratio following exercise in patient 1. For patient 2, we observed a less pronounced acidosis correlated with a lesser amount of Pi produced during exercise. These observations indicate an improvement of mitochondrial function and a shift from high to low glycolytic activity in both patients consequent to CoQ treatment.
authors.affiliation: Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Marseille, France.
authors.forename: D
authors.initials: D
authors.lastname: Bendahan
authors.forename: C
authors.initials: C
authors.lastname: Desnuelle
authors.forename: D
authors.initials: D
authors.lastname: Vanuxem
authors.forename: S
authors.initials: S
authors.lastname: Confort-Gouny
authors.forename: D
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: J F
authors.initials: JF
authors.lastname: Pellissier
authors.forename: G
authors.initials: G
authors.lastname: Kozak-Ribbens
authors.forename: J
authors.initials: J
authors.lastname: Pouget
authors.forename: G
authors.initials: G
authors.lastname: Serratrice
authors.forename: P J
authors.initials: PJ
authors.lastname: Cozzone
mesh_terms: D000293:Adolescent; D000328:Adult; D005080:Exercise Test; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008931:Mitochondria, Muscle; D009132:Muscles / Q000378:metabolism*; D009135:Muscular Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D010084:Oxidation-Reduction; D010758:Phosphorus; D014451:Ubiquinone / Q000627:therapeutic use*
chemical_list: D014451:Ubiquinone; D010758:Phosphorus