[Glycogen phosphorylase activity in infarct-affected and nonaffected parts of the human myocardium after death].

Distinct differences in activity of glycogen phosphorylase were not observed in various parts of an intact human myocardium. This enzymatic activity vas considerably decreased in the left ventricle of the myocardium impaired by infarction; with prolongation of the infarction period the enzymatic activity decreased further. Isozymes of glycogen phosphorylase I, II and III were liberated from ischemic myocardium according to their quantitative ratio in the heart. The glycogen phosphorylase activity, which was observed in blood serum of patients with acute myocardial infarction, was apparently liberated into blood due to the myocardium impairment. Evaluation of the enzymatic activity in blood serum of the patients might serve as an index of the necrosis degree.