Tetrahydrobiopterin-dependent preservation of nitric oxide–mediated endothelial function in diabetes by targeted transgenic GTP–cyclohydrolase I overexpression
J. Clin. Invest. Nicholas J. Alp, et al. 112:725 doi:10.1172/JCI17786 [Go to this article.]

Figure 5
Oxidation of glutathione stores and superoxide generation in aorta from diabetic GCH-Tg and WT mice. (a) The GSH/GSSG ratio was reduced in diabetic WT mice as compared with control WT mice (*P = 0.02, n = 3), but diabetes did not alter the GSH/GSSG ratio in GCH-Tg mice. (b) Lucigenin-enhanced chemiluminescence. Superoxide production in control WT aortas was similar to that in GCH-Tg aortas. Superoxide production was increased more than twofold in diabetic WT aortas as compared with control (*P < 0.05), but this increase was significantly smaller in diabetic GCH-Tg aortas (*P < 0.05 as compared with control and with diabetic WT, n = 4–6). RLU, relative light units. (c) DHE staining for whole-vessel superoxide production. Representative sections are shown (×10), with total red DHE fluorescence expressed in arbitrary units. Aortic DHE fluorescence was increased two- to threefold in both diabetic WT and GCH-Tg mice as compared with their respective controls (**P < 0.01, n = 3). Scale bar: 100 μm. (d) DHE staining for endothelial cell superoxide production. Representative sections are shown (×60), with specific endothelial cell red DHE fluorescence (arrowheads) expressed in arbitrary units. Endothelial DHE fluorescence was increased by more than 17-fold in diabetic WT aorta, whereas endothelial superoxide production in diabetic GCH-Tg aorta was increased only 3.5-fold as compared with control (**P < 0.01, n = 3). Elastic laminas exhibit green autofluorescence. Scale bar: 20 μm.