[Effect of acetylcholine on phosphorylase from skeletal muscle]

Abstract

Acetylcholine (1-10(-5) g/ml) was shown to increase the content of active form of phosphorylase A in homogenate of cat skeletal muscle. Atropine (1-10(-5) g/ml) diminished acetylcholine-induced increase in the phosphorylase activity from 22% to 5.28%. Activating effect of acetylcholine was observed also in superatant (105000 g), although it was 2-fold decreased. No acetylcholine-induced phosphorylase activation was observed in the presence of Mg2+. Addition of Ca2+ (2.2-10(-14) M) did not affect considerably the activation process. It is concluded that the mechanism of acetylcholine-induced phosphorylase activation is different from the effect of adrenaline on phosphorylase.