STUDIES ON THE PASTEUR REACTION IN MUSCLE

1) The Pasteur reaction, in slices and extracts of rabbit muscle, was studied with the employment of glycogen, glucose+hexokinase, and all possible intermediary products of the anaerobic muscle glycolysis as the substrates of the reaction. The forma-tion of both lactic acid and all other products, the consumption of the substrates, and the oxygen uptake were compared under aerobic and anaerobic conditions.<br> 2) The Pasteur reaction was distinct when glycogen and hexosemonophosphates were treated with muscle slices, while the reaction was very slight or negligible in fructosediphosphate, triose-phosphate, phosphoglyceric acid, α-glycerolphosphoric acid, pyruvic acid, and lactic acid.<br> 3) The results obtained with the use of muscle extracts, in the presence of 2.6-diehlorphenolindophenol, were quite similar to those of muscle slices.<br> 4) In the earlier stage of the lactic acid production from glycogen, there remained a larger quantity of glycogen unchanged in the presence of oxygen than in its absence. In the later stage, the Pasteur reaction was accompanied by the accumulation of the Robison ester fraction.<br> 5) It was deduced from these findings that the cause of the Pasteur reaction in muscle could be mainly attributable to the retarding effect of oxygen on the following two reactions of glycolysis; Phosphorolysis of glycogen, and the conversion of fructose-monophosphate into fructose diphosphate. Thus, the Pasteur re-action is not caused by the oxidative removal of the glycolytic intermediates, but by the aerobic retardation of the production of the intermediates. This may suggest that the aerobic and anaerobic decomposition of carbohydrate might proceed along the same path.<br> 6) The Pasteur reaction was markedly inhibited by the addition of adenosinetriphosphate and muscle adenylic acid to the reacting system.<br> 7) The consumption of oxygen had no quantitative con-nection with the Pasteur reaction.