Abstract:

Abstract:Objective
 To investigate the effect of chloride transport in nonspecific phagocytic process of human retinal pigment epithelial(RPE) cells which was treated with DNDS and bumetanide,and to discuss the mechanism for chloride transport’s effort in nonspecific phagocytic process.Methods  Human RPE cells(ARPE-19) were cultivated using millicell cell culture inserts system,and flow cytometry was performed on ARPE-19 cells that had been challenged with fluorescent latex beads.The bumetanide of 1,5,10,50,100,500,1　000 μmol·L^-1 and DNDS of 0.01，0.10，0.50,1.00,3.00,5.00,10.00 mmol·L^-1  were used in the experiment as chloride transport pathway blockers for 6 h,then flow cytometry was used to detect the phagocytic index.Results Compared with control group,different concentrations bumetanide didn’t affect the nonspecific phagocytic process of RPE cells（P>0.05）；when the basal membrane of RPE was treated with  0.01 and 0.10 mmol·L^-1 DNDS,there were no significant differences of phagocytic index compared with control group (P>0.05)；however when treated with 0.50, 1.00,3.00,5.00 and 10 mmol·L^-1 DNDS,the phagocytic indexes were significantly decreased (P<0.05 or P<0.01),and as the concentration increased,the phagocytic indexes were decreased gradually;when the apical membrane of RPE was treated with above concentrations of DNDS,there were no significant differences of phagocytic index compared with control group(P>0.05).Conclusion Apical membrane bumetanide-sensitive Na⁺-K⁺-2Cl^－cotransporter doesn’t participate in the nonspecific phagocytic process of RPE cells,basal membrane DNDS-sensitive Cl－/HCO₃^－ exchange and chloride channel play important roles in the nonspecific phagocytic process of RPE cells.

Key words: retinal pigment epithelial cells;phagocytosis;sodium-potassium-chloride symporters;anion-exchange protein