Erythrocyte choline uptake after renal transplantation

Erythrocyte membrane choline transport is abnormally high in chronic renal failure. The aim of this study was to find out whether, and how quickly, this abnormality is reversed by renal transplantation. Ten adults with chronic renal failure were studied before and for up to 6 months after renal transplantation. Plasma creatinine concentration and erythrocyte uptake of radiolabelled choline were measured periodically for up to 6 months. The maximum rate of choline transport (Vmax) was abnormally high before transplantation and fell to normal values during the first week after transplantation. This fall matched that in plasma creatinine. A temporary rise in plasma creatinine in one patient, reversed by methylprednisolone treatment, was accompanied by a rise in choline flux, and graft failure in another patient was accompanied by a return to pretreatment rates of choline transport. Thus, the high rates of choline uptake in uraemia are rapidly reduced on recovery of renal function. The speed of the changes suggests the involvement of a plasma factor.