Figure 1. Effect of diabetes on the protein levels of AMPA receptor subunits. Total retinal extracts were obtained from rat retinas with diabetes for one, four, and 12 weeks (black bars) and from age-matched control rats (white bars). Extracts were assayed for (A) GluR1, (B) GluR2, (C) GluR2/3, and (D) GluR4 subunits immunoreactivity by western blot analysis. Representative western blots are presented above the bars for each time point tested. The densitometry of each band was analyzed. The results are expressed as percentage of age-matched controls and are presented as the mean±SEM, for the indicated number of animals. In each western blot analysis, a reprobing for detection of α-tubulin was performed to confirm that similar amounts of protein were applied to the gel. The asterisk indicates a p<0.05, the double asterisk indicates a p<0.01, and the triple asterisk indicates a p<0.001, significantly different from control, using the two-tailed Student’s t-test.