Potassium flux of erythrocytes in chronic hemodialysis patients.

BACKGROUND

In chronic hemodialysis patients, hyperkalemia is frequently observed. In these patients, erythrocytes were examined to know whether they participate in the regulation of K(+) or not.

METHODS

Erythrocyte K(+) release (DeltaKr) was induced by the incubation of erythrocyte suspension at 4 degrees C for 24 h and the K(+) influx followed at 37 degrees C for 3 h. K(+) flux of erythrocytes or DeltaKi/DeltaKr ratio, which was reflected by Na(+)/K(+)-exchanging ATPase, was measured in chronic hemodialysis patients. K(+) concentration was measured by ion-selective electrode method.

RESULTS

Non-diabetic hemodialysis patients classified into three groups according to their serum levels were compared for various factors. Among them, the DeltaKi/DeltaKr ratios in medium- and high-serum K(+) groups were significantly lower than those in the low serum K(+) group. The effect of hemodialysis on erythrocyte K(+) flux was examined. After hemodialysis, the mean DeltaKi/DeltaKr ratio increased significantly compared with that before the treatment. Erythrocyte K(+) concentrations converted into a narrower range after hemodialysis.

CONCLUSION

The reduced K(+) flux in erythrocyte may play a part in the development of hyperkalemia in non-diabetic chronic hemodialysis patients.