Figure 5.

Analysis of NOS protein expression and activity in STZ-induced diabetic and control rat retinas. Data shown is the mean ± SEM of six animals in the treated groups and nine animals in untreated groups. A: Analysis of maximal NOS activity by conversion of [³H]-l-arginine to [³H]-l-citrulline in tissue homogenates shows significant increases in NOS activity in diabetic retinas. Treatment of diabetic rats with L-NAME (50 mg/kg/day) or with uric acid (160 mg/kg/day) blocked the increased NOS activity. C, control; D, diabetic; *, P < 0.01 versus untreated control; #, P < 0.05 versus untreated diabetic. B: Western blot analysis shows a significant increase in eNOS expression in diabetic retinas, which is blunted by treatment with L-NAME (50 mg/kg/day) or uric acid (160 mg/kg/day). C: Western blot analysis shows a significant increase in nNOS expression in diabetic retinas, which is blocked by treatment with L-NAME (50 mg/kg/day) or uric acid (160 mg/kg/day).