Red blood cell membrane permeability of uremic and normal cells

Although there is extensive evidence that uremic red cells are more fragile and less deformable than normal cells, there are essentially no data on red cell membrane permeability in uremia. We have obtained data for creatinine and uric acid permeability of red cells from normal and uremic individuals (dialysis patients on EPO). The creatinine permeability of uremic cells was significantly less than that of normal cells (p < 0.02), while the uric acid permeability was significantly greater than that of normal cells (p < 0.01). Experiments with uremic and normal cells suspended in phosphate buffered saline, and with normal cells suspended in uremic plasma, indicated that uremia alters both the red cell membrane and the plasma, with an unknown plasma constituent affecting the permeability.