Effects of NAC on MeHg-induced changes in the expression levels of apoptosis-related proteins in PC12 cells. (A) Western blotting demonstrated the dynamic changes in (B) Bcl-2/Bax ratio, and the protein expression levels of (C) Bax and (D) Bcl-2 in PC12 cells pretreated with 250 µmol/l NAC for 60 min followed by exposure to 2.5 µmol/l MeHg for 48 h. (E) Western blotting demonstrated the dynamic changes in the protein expression levels of (F) pJNK and (G) JNK in PC12 cells pretreated with 250 µmol/l NAC for 60 min followed by exposure to 2.5 µmol/l MeHg for 48 h. Protein band intensity was analyzed after normalization to the corresponding GAPDH levels, and the relative ratios were analyzed after normalization to the corresponding control group. Data are presented as the mean ± SD, n=3. **P<0.01 and ***P<0.001 vs. control group; #P<0.05 and ###P<0.001 vs. MeHg group. MeHg, methylmercury; DHA, docosahexaenoic acid; p, phosphorylated; NAC, N-acetyl-l-cysteine.