Erythrocyte Sodium and Sodium Flux in Relation to Hypertension in Chronic Renal Failure

Erythrocyte sodium and sodium fluxes in plasma and in physiologicalbuffer solution were studied in normotensive and hypertensiveuraemic patients and normal subjects. Erythrocyte sodium wasreduced in the uraemic patients due primarily to low sodiuminflux, further supported by low passive membrane permeability.These differences were much more marked in normotensive patients.There was no evidence for sodium pump inhibition in the erythrocytes.The low erythrocyte sodium influx in the uraemic patients appearedto be due to a plasma factor which could be reversed in youngcells but not in old. However, erythrocyte sodium flux in bothplasma and physiological buffer was lower in normotensive thanin hypertensive uraemic patients. Therefore, a membrane changeto compensate for the effects of the plasma factor on sodiuminflux may be related to the development of hypertension inthe uraemic patients.