Assessment of intracellular magnesium depletion in rat striated muscle by in vivo 31P NMR.

Previous in vivo studies have demonstrated that alpha, beta, and gamma ATP chemical shifts measured by 31P NMR spectroscopy can be used to determine intracellular magnesium in erythrocytes, but up to now such results have not been confirmed in striated muscle in vivo. We report beta ATP chemical-shift in vivo measurements revealing the depletion of free intracellular magnesium in striated muscle of rats fed a magnesium deficient diet.