title: In vivo assessment of mitochondrial functionality in human gastrocnemius muscle by 31P MRS. The role of pH in the evaluation of phosphocreatine and inorganic phosphate recoveries from exercise.
abstract: In this study we compared the kinetics of phosphocreatine (PCr) and P(i) recovery, and their dependency on cytosolic pH in 38 normal individuals. Spectra were acquired during rest, work and recovery. A time resolution of 10 s was used to obtain detailed information. The kinetics of PCr and P(i) recovery almost overlapped when the lowest value of cytosolic pH reached during recovery (termed the minimum pH) was < 6.95, while they were completely dissociated when the minimum pH was > 6.95. This result is interpreted as indirect in vivo evidence of the kinetic control exerted by ADP on mitochondrial oxidation. Our results represent a rationale for new experimental conditions to be used in clinical routine studies of pathologies due to primary or secondary mitochondrial malfunction.
authors.affiliation: Istituto di Patologia Medica D. Campanacci, Università di Bologna, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Iotti
authors.forename: R
authors.initials: R
authors.lastname: Lodi
authors.forename: C
authors.initials: C
authors.lastname: Frassineti
authors.forename: P
authors.initials: P
authors.lastname: Zaniol
authors.forename: B
authors.initials: B
authors.lastname: Barbiroli
mesh_terms: D000328:Adult; D001711:Biotransformation; D003600:Cytosol / Q000378:metabolism; D005069:Evaluation Studies as Topic; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000378:metabolism / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism* / Q000493:pharmacokinetics; D010725:Phosphocreatine / Q000378:metabolism* / Q000493:pharmacokinetics; D010758:Phosphorus
chemical_list: D010710:Phosphates; D010725:Phosphocreatine; D010758:Phosphorus