FIGURE 7.
Increased oxidative stress in mice with increased intraocular IGF-I. Analysis of markers of oxidative stress in WT and Tg-IGF-I animals at different ages. A, levels of oxidized glutathione were higher in transgenic retinas at all ages studied. Values are expressed as the mean ± S.E. of five animals/group. *, p <0.05. B, up-regulation of Nrf2 expression in both young and old transgenic retinas, determined by quantitative PCR. Values are expressed as the mean ± S.E. of 4–5 animals/group. *, p <0.05. Retinal expression of the p67Phox (C) and p22Phox (D) regulatory subunits of the NADPH oxidase enzyme, assessed by quantitative RT-PCR. A marked up-regulation of both subunits was observed in transgenic mice at 3 and 7.5 months of age. E–G, retinal expression of the catalytic subunit of NADPH oxidase, which are expressed in different retinal cell types. E, Nox1; F, Nox2, and G, Nox4 were all markedly up-regulated in transgenic retinas at 7.5 months of age. nd, not detected. Values are expressed as mean ± S.E. of 4–5 animals/group. *, p <0.05. H, retinal expression by quantitative RT-PCR of the enzyme iNOS. There was a marked increase in iNOS expression in transgenic retinas at 7.5 months of age. Values are expressed as mean ± S.E. of 4–5 animals/group. *, p <0.05.