Intracellular ion metabolism in erythrocytes and uraemia: The effect of different dialysis treatments

1. The present report focuses on some aspects of the intra-erythrocytic cation metabolism (e.g. the maximal velocity of the Na⁺–Li⁺ countertransport and Na⁺/K⁺/Cl⁻¹ cotransport) in uraemic patients on different dialysis treatments.

2. Patients undergoing dialysis treatment [continuous ambulatory peritoneal dialysis (CAPD) or haemodialysis (HD)] overall showed higher Na⁺–Li⁺ countertransport than controls. With regard to Na⁺/K⁺/Cl⁻¹ cotransport, CAPD patients and controls did not differ and both showed, on average, higher values than HD patients.

3. A subgroup of HD patients was studied before and after dialysis. No significant overall changes were detected as a result of the dialysis process with regard to Na⁺/K⁺/Cl⁻¹ cotransport. Na⁺-Li⁺ countertransport was significantly reduced by dialysis and a distinctly different response to dialysis was evident according to predialysis values. Patients with high values of Na⁺–Li⁺ countertransport showed a significant reduction in this parameter while patients with normal values showed no effect. No distinct association was detected between alteration in either Na⁺–Li⁺ countertransport or Na⁺/K⁺/Cl⁻¹ cotransport and the clinical characteristics of the patients.

4. It is concluded that uraemia and/or dialysis influences the maximal velocity of the parameters under investigation. The effect on Na⁺–Li⁺ countertransport seems to be similar for both CAPD and HD, while Na⁺/K⁺/Cl⁻¹ cotransport is not altered in CAPD patients.