Endogenous plasma Na,K-ATPase inhibitory activity and digoxin like immunoreactivity after acute myocardial infarction.

The aim was to look for the presence of circulating factor(s) with Na,K-ATPase inhibitory properties and digoxin like immunoreactivity in patients after acute myocardial infarction. Venous blood samples were obtained when the patients were admitted and different methods were used to monitor the plasma concentrations of factor(s) with properties of digitalis. SUBJECTS - These were 26 patients of both sexes (mean age 57.7 years, range 40-72) during the first 24 h of a first transmural acute myocardial infarct, 11 male patients with unstable angina pectoris (52.5 years, 45-67), and 18 healthy male controls (25 to 50 years). There was significant inhibition of ouabain sensitive Na,K-ATPase in intact erythrocytes in patients with myocardial infarction [1.4(SEM 0.15)mumol Pi.mg-1.h-1] compared with patients with unstable angina pectoris [3.1(0.4), p less than 0.01] and healthy controls [3.4(0.25), p less than 0.01]. In myocardial infarction complicated by ventricular fibrillation (n = 5) Na,K-ATPase activity was significantly lower than in the other 21 patients [0.95(0.2) and 1.55(0.11) mumol Pi.mg-1.h-1 respectively, p less than 0.05]. There was no change in erythrocyte Na,K-ATPase activity in myocardial infarction complicated by ac...Continue Reading