Epidermal dipeptide: a new regulatory factor in proliferative vitreoretinopathy.

Proliferative vitreoretinopathy (PVR) is the most severe complication of retinal detachment surgery, occurring approximately in one out of ten operated eyes. The proliferation of retinal pigment epithelial (RPE) cells and fibroblasts is a cornerstone in the pathogenesis of PVR. Since inhibitory peptides may take a part in the feedback mechanism underlying this proliferation, we assessed the effect of synthesized epidermal dipeptide, pyroglu-glyOH (EDP), on the proliferation of RPE cells and fibroblasts in vitro. The maximum inhibitory effect of EDP on the RPE cells was reached at concentrations ranging from 1.0710(-13) to 1.0710(-15) M. Its inhibitory effect on fibroblasts followed a similar pattern at all concentrations applied, 1.0710(-6) to 1.0710(-15) M. These results enhance the possibility that PVR may be due to an imbalance of inhibition/disinhibition mechanism under participation of several regulatory molecules like EDP. EDP might have the potential for reducing the risk of PVR.