Contraction of unstriated muscle without fission of adenosinetriphosphate or creatine phosphate

Summary

1. The fission of ATP and phosphocreatine in frog’s stomach muscle has been studied.

2. In winter, there is no decrease in the concentration of ATP or phosphocreatine due to contraction induced by potassium chloride.

3. In summer, when the muscle is more active and shows frequent spontaneous contractions, there is breakdown of phosphocreatine, but if these muscles are cooled to 0°C.; then there is no change in phosphocreatine content.

4. These experiments suggest that ATP is not the primary substance that supplies energy for contraction in unstriated muscle.