Abstract: 【Abstract】Objective To investigate the relationship between the molecules of aquaporin 1 (AQP1), transforming growth factor- β1 (TGF-β1) and vascular endothelial growth factor (VEGF) and the peritoneal transport function in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods A total of 40 CAPD patients treated in the First Affiliated Hospital of Xinxiang Medical University were enrolled in this study. The levels of AQP1, TGF-β1 and VEGF in serum and 4-hour peritoneal dialysis effluent (PDE) were measured. The CAPD patients were divided into groups according to the characteristics of peritoneal transport function, dialysis duration and ultrafiltration volume. The relationship between peritoneal transport function and the levels of AQP1, TGF-β1, VEGF and biochemical markers were analyzed. Result ①Daily ultrafiltration volume and serum urea nitrogen were significantly lower in the high-high-average peritoneal transporter (H-HA) group than in the low-low-average peritoneal transporter (L-LA) group (t=2.420, P=0.020; t=2.478, P=0.018). ②In H-HA group, TGF-β1 in serum and PDE were higher than those in L-LA group
(t=- 2.719, P=0.010; t=- 3.407, P=0.002), VEGF in serum and PDE were higher than those in L-LA group (t=- 2.977, P=0.005; t=- 2.553, P=0.015), but AQP1 in PDE was lower than that in L-LA group (t=2.391,P=0.022). ③In long-term dialysis group, TGF-β1 and VEGF in serum were higher than those in short-term dialysis group (F=4.025, P=0.026; F=4.197, P=0.023); VEGF in PDE was higher than that in short-term dialysis group (F=4.547, P=0.017). AQP1 in serum was lower in mid-term and long-term dialysis group than in short-term dialysis group (H=9.504, P=0.009). ④Correlation analyses showed that ultrafiltration volume was
positively correlated with AQP1 in PDE (r=0.776, P＜0.001), and was negatively correlated with TGF-β1 and VEGF in PDE (r= -0.825, P＜0.001; r=-0.385, P=0.014). ⑤Logistic regression analyses found that AQP1 in PDE was a protective factor for ultrafiltration (OR=0.514, 95% CI 0.280～0.946, P=0.033). Conclusion Higher TGF-β1 and VEGF in serum and PDE were present in long-term dialysis patients, and lower ultrafiltration volume was present in high-high-average peritoneal transporter (H-HA) patients, suggesting that peritoneal fibrosis and vessel proliferation may result in the increase of solute transportation and the decrease of ultrafiltration volume. AQP1 in PDE was a protective factor for ultrafiltration in CAPD patients.

Key words: Aquaporin 1, Transforming growth factor-β1, Vascular endothelial growth factor, Peritoneal dialysis, Peritoneal transport function