Glycogen phosphorylase activities in skeletal muscle and heart of genetically dystrophic Syrian hamster.

A simple, rapid and reliable procedure of tissue preparation was devised to estimate glycogen phosphorylase activity in cardiac and skeletal muscle of normal and genetically dystrophic Syrian hamsters of various ages. Total phosphorylase activities of dystrophic skeletal muscle, compared to normal, were reduced. Except for the case of heart from the younger dystrophic animals (45 days old), in which higher phosphorylase activity was noted, hearts from dystrophic hamsters, compared to normal, also showed reduced phosphorylase activities. There were, however, no significances in the ratios of phosphorylase alpha to total phosphorylase between the normal and dystrophic tissues.