Studies with a reconstituted muscle glycolytic system: The anaerobic glycolytic response to simulated tetanic contraction

Abstract

By using a reconstituted glycolytic system and a highly active adenosine triphosphatase (ATPase), the metabolism during muscular tetanic contraction was simulated and observed. With an ATPase activity somewhat greater than can be maintained in muscle tissue, phosphocreatine was rapidly and completely utilized, lactate production commenced about 5 sec after the ATPase was added and after 15 sec adenine nucleotides were lost through deamination to IMP. By 40 sec, all metabolism ceased because of complete loss of adenine mononucleotides. With a lower ATPase activity, glycolytic regeneration of ATP was capable of maintaining the ATP concentration at its initial value and even by 80 sec, only one half of the phosphocreatine had been utilized. No deamination occurred in this time. It is suggested that the metabolic events observed in the simulated system are basically the same as occur in muscle doing heavy work.