Douglas E. Befroy1, Ryan G. Larsen2,
Michael A. Tevald2, Jane A. Kent-Braun2
Several
MRS methods have been developed to investigate muscle mitochondrial function
in-vivo. Although some studies have detected alterations in oxidative
metabolism in the elderly and type-2 diabetes, others have discerned no
effect. Resolving these disparities is confounded by differences in subject
selection and muscle metabolic phenotype between studies, and by methodological
differences between techniques. To establish whether correlated or
independent parameters of mitochondrial metabolism are assessed by these
methods, we have directly compared three 31P-MRS techniques:
resting Pi → ATP flux, ischemic PCr decline and
post-contraction PCr recovery, in a single muscle compartment in a group of
healthy male subjects.