Murine BM and blood cells were collected for intracellular reactive oxygen species test after limb ischemia at day3 and 21. Mice without limb ischemia were used as control. Limb ischemia significantly increased intracellular reactive oxygen species production in BM and blood mononuclear cells that was effectively prevented by NAC treatment in mice. *Day3 or 21 vs Baseline, P <0.05, n≥8; $Day21 vs 3, P <0.05, n≥8; #ctrl vs NAC, P <0.05, n≥8.