MPO and Sepsis: Protective effects of sildenafil on the lung and extrapulmonary organs were exerted in a polymicrobial sepsis in rats where sildenafil increased total glutathione (GSH), and decreased an activation of MPO, and decreased malondialdehyde (MDA) as a marker of lipid peroxidase, and superoxide dismutase (SOD) in the lung and kidney of septic rats.