Inhibition of Nox 4 expression by PPARα in OIR. (A) At P17, retinal Nox 4 was measured by Western blotting in WT RA and OIR mice treated with Veh or FA, semiquantified by densitometry, normalized by β-actin levels, and expressed as the ratio to that in the RA control (n = 6). (B) At P17, retinal Nox 4 was measured by Western blotting in PPARα−/− RA and OIR mice treated with Veh or FA and quantified as above (n = 6). (C) In P17 WT and PPARα−/− RA and OIR mice, retinal Nox 4 expression was measured as described above (n = 6). All values are mean ± SEM. *P < 0.05, **P < 0.01.