31 P NMR studies of the metabolic changes in the prawns Palaemon serratus and P. elegans during exercise

In vivo 31P NMR (Nuclear Magnetic Resonance Spectroscopy) was used to examine the changes in phosphometabohtes in the abdominal muscle of 2 closely related prawns, Palaemon serratus and P. elegans, after exercise. Two types of exercise were produced by electrical stimulation: brief maximal exercise and exercise to exhaustion. ATP was extracted and analyzed by HPLC to calculate the absolute concentrations of metabolites measured by NMR. The main findings were: (1) At rest, P. serratus had lower muscle concentrations of phosphoarginine, arginine and ATP than P. elegans. (2) During exercise, the ATP concentration in P. serratus muscle decreased by 23 % from that at the start of the exercise, while that of P. elegans remained unchanged. (3) The patterns of post-exercise phosphometabolite recovery in the 2 species were similar. Thus, P. elegans, which is more tolerant of environmental anaerobiosis, is also more able to maintain its cellular energy state during bursts of muscular activity.