Figure 3.

Systemic administration of NaIO3 results in significant degeneration of the RPE and photoreceptors, which is prevented by pretreatment with the small peptide antagonist of the Fas receptor, Met12. (A) Low- and high-power photomicrographs of retinas from animals at various time points after systemic exposure to NaIO3. Eyes were pretreated with intravitreal injection of either Met12 (a1–d1, a2–d2) or an inactive, scrambled peptide, mMet12 (a3–d3, a4–d4). NaIO3 exposure resulted in significant disruption of the RPE by 7 days in the mMet12-treated eyes (b3, b4), which was prevented by Met12 treatment (b1, b2). By 1 month post exposure to the NaIO3, the overlying retina was severely degenerated in the mMet12-treated eyes (c3, c4, d3, d4) but not in the Met12-treated eyes (c1, c2, d1, d2). (B) There was a significant reduction in the number of retinal folds, or (C) extent of retina damaged as measured from the optic nerve after NaIO3 exposure in eyes that were pretreated with Met12 as compared to mMet12. *P < 0.05). Scale bars: low magnification images 200 μm, high magnification images 25 μm. GCL, ganglion cell layer; INL, inner nuclear layer; ONL, outer nuclear layer.