Figure 7. Effect of diabetes on expression of VEGF and VEGF–associated genes. qRT-PCR analysis was performed on cDNA isolated from control and STZ-induced diabetic rat retinas after 4 and 12 weeks. Expression of each gene was normalized to acidic ribosomal phosphoprotein (P0) for each rat (A), and then scaled to the 4-week control rats for each gene (B; mean ± SEM). The retina expresses erythropoietin (EPO) at low levels, yet diabetes significantly increased EPO transcript levels (significant main effect for treatment factor; +, p<0.05). The transcriptional expression of VEGFA, the vascular endothelial growth factor (VEGF) receptors FLT1 and KDR, and erythropoietin receptor (EPOR) did not change with diabetes.