The effect of haemodialysis on tubular secretion of creatinine in residual nephrons.

In a group of 16 patients on regular haemodialysis treatment, inulin and creatinine clearance was examined before and 12 h after haemodialysis. Inulin clearance (CIn) decreased significantly (P less than 0.001) whereas creatinine clearance (CCr) did not change after haemodialysis. The CCr/CIn ratio increased significantly (P less than 0.05) as did calculated tubular secretion of creatinine (TCr) (P less than 0.01) and TCr/CIn 100 (P less than 0.001). The results suggest that uraemic sera contain dialysable substance(s) depressing tubular secretion of creatinine.