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

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- cotransport) in uraemic patients on different dialysis treatments. 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- cotransport, CAPD patients and controls did not differ and both showed, on average, higher values than HD patients. 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- 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- cotransport and the clinical characteristics of the patients. 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- cotransport is not altered in CAPD patients.