Figure 1. Changes in NO-induced fluorescence (NO-IF) in the diabetic retina. A: NO-IF increased in the diabetic retina compared to control. NO-IF in processes from somata in the inner nuclear layer (INL) were present in control (white arrowhead) but absent in the diabetic. Treatment with insulin or aminoguanidine (AG) reduced NO-IF and insulin restored NO-IF in some the processes in the INL (white arrowheads). Scale bars represent 25 μm. Quantitative analysis of NO-IF in retinal regions is shown in dark-adapted unstimulated (B) and light-stimulated retinas (C) as compared to control (100%). The outer and inner plexiform layers (OPL and IPL) depict the percent intensity, while the inner nuclear layer (INL) and ganglion cell layer (GCL) depict the percent of NO-IF labeled somata. B, C: Like symbols indicate statistically significant differences between groups (* represents diabetic versus control OPL, # represents diabetes versus control IPL; p<0.05). Error bars represent SD.