Murine BM and blood cells were collected to determine the apoptotic rate at day3 and 7 using flow cytometry analysis. Mice without limb ischemia were used as control. There was no significant change in the BM cell apoptotic rate at day 3 and day 7 after limb ischemia. However, the apoptotic rate of blood mononuclear cells was significantly decreased at day 7 following limb ischemia. When the mice were pre-treated with NAC, there was no significant change in the apoptotic rate in BM and blood mononuclear cells after limb ischemia compared with the control except decreased late apoptosis for BM mononuclear cells with NAC treatment. *Day3 or 7 vs Baseline, P <0.05, n≥8; $Day7 vs 3, P <0.05, n≥8.