Effect of stimulation on phosphorylase levels of excised anterior tibial muscles of the mouse

The effect of electrical stimulation on the activation of phosphorylase in mouse muscle was investigated. Rapid interruption of chemical events was accomplished by simultaneously quick-freezing resting and stimulated paired muscles. Phosphorylase ( a/t) ratios (%) were found to be significantly increased after 1 1/2, 3, 15, and 30 sec of stimulation; the increase was not significant after 1/2 sec. The present study shows that phosphorylase is activated with sufficient priority to bring about increased rates of glycogenolysis relatively early during the tetanic contraction of mouse muscle.