Several authors described a significant decrease of erythrocyte membrane-enzyme activities in hepatological disease. There are no data, if deterioration of Na+/K+-ATPase activity is present in children, suffering in such a condition.

Twenty-two children with chronic liver disease were enrolled to the study. In 11 of them cholestasis was present. The Na+/K+-ATPase activity was measured on detergent pretreated erythrocytes (DPE) and on hemoglobin free red blood cell membranes (ghosts).

In all of the patients Na+/K+-ATPase activity in DPEs was lower (1823±717 vs. control 3183±754 nmolP/mlRBC/h, p<0.05). The non-cholestatic patients had higher Na+-K+ pump-activity compared to the cholestatic children (2134±787 vs. 1513±786 nmolP/mlRBC/h, p<0.05). The ghost Na+/K+-ATPase activity was depressed in all of the patients (224±119 vs control 399±120 nmolP/mg.prot/h, p<0.01). This case there was no difference between the cholestatic and non-cholestatic group.

These results indicate, that in children with chronic liver disease the Na+-K+ pump activity is depressed. In cholestatic state there might be some inhibitor(s) contributing to the depressed function of Na+/K+-ATPase, which are probably washed out during the preparation phase of ghosts. Further investigation is needed to elucidate this phenomenon.