Alterations of the Cl-/NaCO3- anion exchanger in erythrocytes of uraemic patients.

We have studied the transport activity of the erythrocyte anion exchanger by measuring the DIDS-sensitive Li+ influx in fresh red blood cells incubated in HCO3- medium. In addition, the amount of erythrocyte band 3 protein was determined by electrophoretic analysis. The study was performed in twenty uraemic patients on chronic haemodialysis (12 males and 8 females, mean age 47.9 years), and in 20 healthy controls (10 males and 10 females, mean age 44.7 years). Mean time on haemodialysis was 63.9 months (range 6-170 months). The DIDS-sensitive Li+ influx was decreased in erythrocytes from uraemic patients as compared to erythrocytes from controls (619.6 +/- 34.1 vs 761.2 +/- 36.6 mumol/l cell x h, P less than 0.01). The content of band 3 protein was decreased in erythrocytes from uraemic patients as compared to erythrocytes from controls (30.01 +/- 0.39 vs 32.12 +/- 0.48%, P less than 0.01). These results indicate that the Cl-/NaCO3- anion exchanger is altered in erythrocytes from uraemic patients in chronic haemodialysis, and suggest that the regulation of ion content may be compromised in the red blood cells of these patients.