Figure 11. Inhibition of ERK activation using MEK inhibitor U0126 led to decreased accumulation of RIP3 but not of RIP1 in the IR-injured rat retina. A: The amount of phosphorylated ERK protein (p-ERK) at 12 h post-ischemia reperfusion (IR) decreased in the animals treated with 0.4 or 0.8 mM U0126 relative to the solvent- (5% DMSO) or saline-treated animals. The decreased amount of p-ERK protein in the animals treated with 0.8 mM U0126 was significant compared to the groups treated with saline, solvent (5% DMSO), or 0.4 mM U0126. B: The amount of accumulated RIP3 protein at 12 h post-IR decreased in the animals treated with 0.4 or 0.8 mM U0126 when compared with the solvent- (5% DMSO) or saline-treated animals. The decreased amount of RIP3 in the animals treated with 0.8 mM U0126 was significant compared to the groups treated with saline, solvent (5% DMSO), or 0.4 mM U0126. C: There was no difference in the accumulation of the RIP1 protein at 12 h post-IR in the animals treated with 0.8 mM U0126 compared to the groups treated with saline, solvent (5% DMSO), or 0.4 mM U0126. Data are presented as mean ± standard error of the mean (SEM). *p<0.05, ***p<0.001.