Glycyl-prolyl-p-nitroanilidase (GPNAase) activity in cardiovascular diseases

We have studied serum glycyl-prolyl-p-nitroanilidase (GPNAase) activity and its distribution in various parts of the body in patients with acute myocardial infarction, chronic ischemic heart disease, valvular heart disease with or without congestive heart failure and essential hypertension. Serum GPNAase activity in patients with acute myocardial infarction was significantly lower as long as 12 days after the onset as compared with normal controls. The serum enzyme activity in patients with congestive heart failure was also significantly lower than that of controls and there was a tendency of its gradual decrease with the progress of the disease. There was no significant difference between the activity in control group and that in age-matched patients with essential hypertension. There was no significant change of the activity in patients with chronic ischemic heart disease. The GPNAase activities in sera obtained from various parts of the body by cardiac catheterization were essentially similar.