Study of muscle metabolism by Magnetic Resonance Spectroscopy (31P-MRS) in healthy volunteers

Abstract

Phosphorus 31 Magnetic Resonance Spectroscopy (31P-MRS) is a powerful technique for evaluating human muscular metabolism. Some reports indicated the behavior of phosphorylated metabolites (PCr, ADP and Pi) and other indirect parameters (intracellular pH and [Mg2+]) in muscles at rest and after an exercise load. The aim of this work is a quantitative study of the phosphorylated metabolite levels in the calf muscle of normal subjects at rest and post-exercise, in order to create a normal control database. 31P spectra of seven volunteers were acquired in both conditions. Firstly, different quantification methodologies were evaluated to use the more reliable. The PCr metabolite was the more stable at rest and it had mono-exponential behavior after exercise. The Pi was the more sensible indicator of the physical activities. The time constants of the recuperation process are report for all the evaluated metabolites and parameters. Finally, the temporal behavior of phosphomonoesters was quantified.