Figure 4. Comparison of diabetes-induced changes in inflammatory molecules among rat strains. Diabetes of four months’ duration increased retinal expression of (A) inducible nitric oxide synthase (iNOS), (B) cyclooxygenase 2 (COX2), and (C) vascular endothelial growth factor (VEGF) in Sprague Dawley, Lewis, and Wistar rats. All diabetes-induced increases were statistically significant, except that COX2 expression only tended to increase in Lewis rats. Expression data are expressed as a ratio to expression of actin in the same sample. Groups contained six animals per group. Mean±SEM.