Effects of NAC on oxidative stress. Data are presented as the mean ± standard error of the mean of three independent experiments (n=3 per group) ***P<0.001, SCI+VEH mice versus SHAM+VEH mice; ###P<0.001, SCI+NAC mice versus SCI+VEH mice; ΔΔΔP<0.001, SCI+NAC mice versus SHAM+NAC mice; πP<0.05, SHAM+NAC mice versus SHAM+VEH mice. (A) HO-1 expression by quantitative immunoblot analysis was performed at the indicated time points in SHAM and SCI mice treated with NAC or VEH. (B) Modified Perl’s staining was performed to detect non-heme iron in SHAM and SCI mice treated with NAC or VEH at 14 days. Scale bar indicates 500 μm. Accumulation of non-heme iron detected by Perl’s staining was analyzed using NIH Image J and expressed as integrated density measurements. (C) ELISA of SOD was performed at 24 h in SHAM and SCI mice treated with NAC or VEH. (D) ELISA of GSH-Px was performed at 24 h in SHAM and SCI mice treated with NAC or VEH. (E) Correlation between mitochondrial RCR and oxidative stress in injured spinal cord. NAC, N-Acetyl-Cysteine; VEH, vehicle; SCI, spinal cord injury; RCR, respiratory control ratio; SOD, superoxide dismutase; GSH-Px, glutathione peroxidase; HO-1, heme oxygenase-1.