Figure 2. Effects of vascular endothelial growth factor (VEGF) in oxidative stress induced cytotoxicity in retinal ganglion cell (RGC)-5 cells. A: Hydrogen p 258 eroxide dose response curve, following 24 h exposure, revealed 30%–35% reduction in cell numbers at 700 and 800 μM doses. Higher doses resulted in 80% reduction (*p-value<0.005). B: VEGF-mediated protection was evaluated in parallel wells, where hydrogen peroxide (800 μM)-treated cells are compared with cells treated with VEGF alone. There was a reduction in percentage decrease of cell numbers when cells were co-treated with VEGF and H₂O₂, compared with controls administered in a dose-dependent manner with increasing doses of VEGF. The maximum protection was provided at the 200 nM dose (p=0.001). C: Treatment with the glutathione reductase inhibitor buthionine sulfoxime (BSO) increased H₂O₂-mediated reduction in cell numbers by 22%. hVEGF165 at 200 ng/ml provided the greatest protection, increasing cell numbers by 8%, p<0.0005. Cell numbers were determined using a Water Soluble Tetrazolium (WST)-1 assay and are expressed as percent of control. H₂O₂: hydrogen peroxide.