Fig. 2.

A mixture of antioxidants prevents progressive lipid peroxidation in the retinas of rd1 mice between P18 and P35. rd1 mice were killed at P18 or divided into two groups and given daily injections between P18 and P35 of vehicle or vehicle containing a mixture of four antioxidants, α-tocopherol, MnTBAP, ascorbic acid, and α-lipoic acid. Ocular sections were stained with an antibody that specifically recognizes acrolein–protein adducts (a biomarker for lipid peroxidation) and a secondary FITC-labeled antibody (column 2), rhodamine-conjugated PNA that stains cones (column 1), and Hoechst, which stains all cell nuclei (column 4; to conserve space, the outer nuclear layer is labeled cones, but there are still some rods remaining at P18). All of the sections shown in column 2 were stained at the same time, and the results were identical in two mice from each group. There was some mild staining for acrolein in P18 rd1 mouse retina (column 2, row 2), and it was increased in P35 rd1 mouse retina (column 2, row 3). There was no detectable acrolein staining in cones at P18, but there was strong staining in remaining cones at P35 (columns 2 and 3, row 3) and increased staining in the inner nuclear layer (INL). Treatment with antioxidants between P18 and P35 resulted in a marked decrease in acrolein staining in rd1 mouse retina at P35 (column 2, row 4). The cones in vehicle-treated retinas from P35 rd1 mice are yellow in merged images (column 3, row 3), indicating oxidative damage in cones, and the lack of yellow staining in antioxidant-treated P35 rd1 mice (column 3, row 4) indicates that the oxidative damage in cones was substantially reduced by the antioxidant treatment.