Abstract: Objective To investigate the influence of different dialysis models on plasma endothelin (ET) and serum endogenous digitalis-like substance (EDLS) in patients with chronic renal failure. Methods We enrolled 75 maintenance hemodialysis (MHD) patients to assign them randomly and equally into 3 groups: LFHD group in which patients were treated with low-flux hemodialysis, HFHD group in which they were treated with high- flux hemodialysis, and HDF group in which they were treated with hemodiafiltration. We also collected 20 healthy participants as controls. Plasma ET and serum EDLS were measured by radioimmunoassay in MHD patients before and after hemodialysis and controls. Results Plasma ET and serum EDLS were significantly higher in MHD patients than in the healthy controls (P<0.01). In LFHD group after treatment, plasma ET increased from 74.58±11.09pg/ml to 89.97±26.09pg/ml (P<0.01) and serum EDLS decreased from 246.59±25.73pg/ml to 211.96±25.01pg/ml (P<0.01). In HFHD group after treatment, plasma ET increased from 75.27±17.58pg/ml to 80.70±23.83pg/ml but without statistically difference (P>0.05), while serum EDLS decreased from 250.92±28.71pg/ml to 212.56±27.40pg/ml (P<0.01). In HDF group after treatment, plasma ET decreased from 76.66±17.53pg/ml to 68.69±17.48pg/ml (P<0.05), and serum EDLS decreased from 251.17±23.13pg/ml to 210.65±20.60pg/ml (P<0.01). Plasma ET increased in LFHD and HFHD groups after treatment, but decreased in HDF group after treatment (P<0.05, as compared with that in LFHD group). Serum EDLS decreased in LHFD, HFHD and HDF groups, but without statistical differences among the three groups (P>0.05). Conclusions Serum EDLS decreased significantly in LHFD, HFHD and HDF groups. In addition, plasma ET decreased preferably in HDF group.

Key words: Hemodiafiltration, Endothelin, Endogenous digitalis-like substance