The effect of digoxin on 86rubidium uptake by erythrocytes from mothers and babies

1 The uptake of 86rubidium by erythrocytes from mothers and babies has been used as a model system to investigate possible differences in sensitivity to digoxin in the very young. 2 While total 86rubidium uptake was not significantly different between mothers and babies, the digoxin-sensitive proportion was higher in neonatal erythrocytes. Neonatal cells were less sensitive to digoxin, demonstrated by the requirement for a larger amount of digoxin to inhibit 86rubidium uptake and this was accompanied by an increase in numbers of specific erythrocyte binding sites for digoxin. 3 These results provide further evidence in support of the hypothesis of decreased sensitivity to digoxin in the very young.