Fig. 2

DADLE exerted cytoprotective effects in OGD/R cells and elevated postischemic DOR levels in vivo and vitro. The viability of SH-SY5Y cells exposed to gradient concentrations of DADLE in normal culture (a) and under OGD/R conditions (b) (N = 4 per group, three independent experiments). c The viability of SH-SY5Y cells treated with OGD/R and DADLE, naltrindole or DADLE + naltrindole (N = 4 per group, three independent experiments). d Western blot analysis of DOR expression in SH-SY5Y cells following OGD/R injury (N = 6 per group). e Western blot analysis of DOR levels in the rat hippocampus on day 3 after ischemia (N = 3 per group). The values are shown as the mean ± SEM. There were no significant differences between groups in a. Significant differences: the OGD/R group vs. the 10 μM, 20 μM and 30 μM DADLE groups (***p < 0.001) in b; the OGD/R group vs. the DADLE group (*p < 0.05) and the naltrindole group (p > 0.05, ns), the DADLE group vs. the DADLE + naltrindole group (***p < 0.001) in c; the OGD/R group vs. the DADLE group (*p < 0.05) and the naltrindole group (p > 0.05, ns), the DADLE group vs. the DADLE + naltrindole group (*p < 0.05) in d; the I/R group vs. the DADLE group (**p < 0.01) and the DADLE group vs. the DADLE + naltrindole group (**p < 0.01) in e. DAD DADLE, Nal naltrindole