MPO and Sepsis: Levels of MPO in lung tissues in control group, sepsis group, sepsis+SO2 group, and SO2 group were 4.05 ± 3.084 U/g, 8.26 ± 0.637 U/g, 6.11 ± 0.195 U/g, and 6.88 ± 0.444 U/g, respectively.