the hypothesis that digitalis-induced arrhythmias occur when na , k-atpase inhibition exhausts the sodium pump reserve capacity , producing an accumulation of intracellular na+ , was tested by reducing the reserve capacity in isolated left atrial muscle of guinea pig heart and estimating specific digoxin binding and na , k-atpase activity in atrial muscle homogenized at the onset of digoxin-induced arrhythmias .
C0001473
atpase
C0001479
sodium pump