Effect of bradykinin on cultured retinal pigment epithelial cells

Inflammation plays a key role in the development of proliferative vitreoretinopathy (PVR). This study aimed to detect the effects of bradykinin (BK) on retinal pigment epithelium (RPE) cells, especially regarding inflammation and collagen formation, and to investigate the possible pathway, including the receptors and downstream molecules. We found that BK induced an increase in Ca2+ and the levels of COX-2 and iNOS. The collagen formation was decreased with 100 nM BK treatment on the ARPE-19 cells (0.840 +/- 0.030, P = 0.011). Moreover, in the B1R and B2R antagonistic groups, BK could improve the level of collagen compared with the BK-only-treated group (B1R antagonistic groups: 0.857 +/- 0.021, P = 0.007; B2R antagonistic groups: 0.907 +/- 0.015, P = 0.009). These results suggest the potential use of BK as a therapeutic agent to prevent the development of PVR.