MPO concentrations in lung homogenates from the reperfusion group were much higher than those of the NO inhalation group, ischemia, and sham groups (11.74 ± 1.63 vs. 10.29 ± 1.70 ng/mL, P < 0.05, 11.74 ± 1.63 vs. 9.08 ± 0.46 ng/mL, P < 0.05 and 11.74 ± 1.63 vs. 8.30 ± 2.13 ng/mL, P < 0.05, respectively) (Fig. 3-2). This evidence concerns the gene MPO and ischemia.