Abstract: Objective To investigate the role of anion exchange in nonspecific phagocytic process of human retinal pigment epithelial (RPE) cells. Methods Fluorescent latex beads were incubated with RPE cells at 37℃, flow cytometry was performed on RPE cells that had been challenged with fluorescent latex beads. The quantity of phagocytosis was expressed as a phagocytic index. Experiments were also performed in the presence of different concentration anion exchange blocker DIDS（1，10，100，200，300，500 and 1 000 μmol•L^-1）.Results Phagocyticindex of RPE cells was (35.1±1.6)% at 6 h of incubation without DIDS. Phagocytic index of RPE cells was (34.1±2.1)% in the presence of 1 μmol•L^-1 DIDS（P>0.05）. Phagocytic index of RPE cells was (28.7±1.9)% in the presence of 10 μmol•L^-1 DIDS，10μmol•L^-1 DIDS significantly inhibited the nonspecific phagocytic process of human RPE cells（P<0.05）, and DIDS inhibited the process in concentration-dependent manner. Phagocytic index of RPE cells was (23.0±1.2)%，(17.9±1.5)%，(12.0±1.6)%，(7.0±2.2)% and (5.0±2.5)% in the presence of 100，200，300，500 and 1 000 μmol•L^-1 DIDS (P<0.01).Conclusion The inhibition of anion exchange activity will result in the decrease of nonspecific phagocytosis in RPE cells, anion exchange maybe participate in the nonspecific phagocytic process of RPE cells.

Key words: phagocytosis, chloride-bicarbonate antiporters