As for the expression levels of these enzymes in whole retina extracts, they also corresponded to the alterations observed in the protein levels (Fig. 5D and 7B): there were no variations at 7 days of diabetes induction, while at 30 days there was a significant decrease in the expression levels of AK [0.85±0.06 fold decrease from control (p<0.05)] and ADA [0.68±0.12 fold decrease from control (p<0.05)]. This evidence concerns the gene ADA and diabetes mellitus.