Gamma-Glutamyl-Transpeptidase in Myocardial Infarction

Abstract

The activity of γ-glutamyl-transpeptidase was determined serially in patients with acute myocardial infarction up to 32 days after the onset of chest pain. Peak enzyme activity was found in all patients between the eighth and eleventh day after infarction. Some patients showed a rise in serum activity 48 hr after infarction. In 33 mongrel dogs with experimental myocardial infarction, γ-glutamyl-transpeptidase activity was estimated in the homogenate of the normal and necrotic heart muscle as soluble and particle-bound enzyme activity. The changes of free and particle-bound activity showed different patterns. The soluble enzyme activity was highest during the first 4 days and approached normal level after 8 days. Particle-bound activity was significantly decreased after 24 hr and showed thereafter a continuous rise to 10 times the control values 10 days after the coronary artery occlusion. These studies indicate that several determinations of γ-glutamyl-transpeptidase activity in serum of patients with myocardial infarction may reflect the reparative processes taking place in the infarcted tissue.