Expression of aquaporin-1 in human peritoneum and its effect on peritoneal dialysis patients with the different peritoneal transport characteristics

Objective To investigate the expression of aquaporin-1 (AQP1) in human peritoneum and its effect on peritoneal dialysis (PD) patients with the different peritoneal transport characteristics. Methods Peritoneal biopsies were obtained from the PD patients (n=30) at catheter insertion. Western blot and immunohistochemical staining were used to investigate AQP1 expression in peritoneal tissues. After catheter insertion, 4 week, peritoneal equilibrium test (PET) was used to decide peritoneal transport characteristics. Results Western blot revealed a major band at 28 kDa band. The expression of AQP1 index was 1.49±0.67 in the normal subjects, and 1.61±0.76 in the PD patients, and there was no significant difference. Positive deposition was distributed in mesothelial cells, endothelial cells of capillaries, and small veins. The index of AQP1 expression in endothelial cells of capillaries in normal subjects and PD patients were 2.12±0.18, and 2.50±0.81, respectively, and no significant difference was found. The index of AQP1 expression in mesothelial cells of capillaries in normal subjects and PD patients were 1.95±0.67, and 2.23±1.07, respectively, and no significant difference was found. Among PD patients, the level of AQP1 was significantly different. Conclusions The expression of AQP1 was different in the PD patients with different peritoneal transport characteristics. In the high and high average transport groups, the level of AQP1 was lower; the low transport group was higher. It reveals that AQP1 plays a role in the pathogenesis of transcellular water transport. Key words: Aquaporins/biosynthesis; Peritoneal dialysis; Peritoneum/metabolism; Immunohistochemistry; Blotting, Western