Meeting Abstract

P2.68  Friday, Jan. 4  Creatine increases intensity of muscle power in early vertebrates SOKOLOWSKY, K P*; ROOT, R G; Lafayette College; Lafayette College robroot@lafayette.edu

The phosphagens creatine and arginine act in the form of their phosphorylated counterparts, phosphocreatine (PCr) and phosphoarginine (PA), as quick energy sources and ATP buffers during anaerobic respiration. A simple model was developed based on the chemical equations ADP + Pi ATP and PX + ADP + H+ X + ATP where X is the phosphagen and PX the phosphorylated compound. By altering the forward rate constant and equilibrium rate constant of the phosphagen reaction to depict either creatine or arginine, the model can portray the effects of either phosphagen on ATP metabolism. The differences between creatine and arginine as shown by the model suggest why early vertebrates may have developed a creatine, as opposed to arginine, phosphagen system. Comparing concentrations [ATP] versus [PCr] and [ATP] versus [PA] shows that PCr creates and maintains a higher [ATP] while PA can maintain a lower [ATP] but for a longer time period. These observations align with the hypothesis that early vertebrates needed muscle metabolism to support short power bursts to escape predators or catch prey and began using a creatine phosphagen system to do so.