CHANGE IN CHEMICAL-SHIFT AND SPLITTING OF P-31 GAMMA-ATP SIGNAL IN HUMAN SKELETAL-MUSCLE DURING EXERCISE AND RECOVERY

Proton decoupled P-31 in vivo NMR spectroscopy of the human finger fle xor muscles was performed during exercise and recovery using a 1.5 T w hole-body imager, Predominantly the gamma-ATP signal shows a splitting caused by different signal contributions with chemical shifts that va ry independently, Studies on the human gastrocnemius and biceps femori s muscle were undertaken to investigate the appearance of the splittin g in these muscles as well, In all cases more than one signal contribu tion was found which might represent the different muscle fibre types and their recruitment pattern following exercise, An analysis of the c hemical shifts (delta) of ATP results in changes of up to 0.4 ppm and 0.1 ppm for delta gamma- and delta beta-ATP, respectively, Based solel y on the chemical shifts of the ATP P-31 signals the tissue pH value f ollowing exercise was determined. The result was in good agreement wit h the value derived from delta P-i.