1H NMR Determination of lactate 13C-enrichment in skeletal muscle: Using a double quantum filter for the simultaneous editing of 13C-coupled and 13C-uncoupled methyl protons resonance

¹H NMR simultaneous editing of ¹³C-coupled and ¹³C-uncoupled methyl protons resonance, using the selection of double quantum coherences by a gradient pulse, was analyzed in vitro and demonstrated in situ on the hindlimb of an exercised rat model postmortem. In vitro calibration showed agreement with theoretical analysis. High-resolution NMR of muscle extract confirmed the accuracy of the lactate ¹³C-enrichment calculated using the in situ NMR data and the calibration factor obtained in vitro.