Fig. 4.

Rapid degeneration of photoreceptors prevents diabetes-induced generation of superoxide by mouse retina. Photoreceptor degeneration was induced with IAA. (A) Compared with wild-type control N and D mice, essentially all photoreceptors were missing from mouse retina 7 d after i.p. injection of IAA. ∆, N wild-type; ■, D wild-type; ▲, N+IAA; □, D+IAA. (B) Likewise, the diabetes-induced increase in retinal superoxide production seen in control mice was essentially prevented in diabetic mice lacking photoreceptors as a result of IAA treatment. Data are expressed as a percent of the value of nondiabetic wild-type controls. Duration of diabetes was 2 mo at the time of this assay (n = 3–5 per group, 4 mo of age when killed).