N-acetylcysteine inhibits peroxynitrite-mediated damage in oleic acid-induced lung injury

Abstract

Since oleic acid (OA) induces morphologic and cellular changes similar to those observed in human acute lung injury (ALI) and acute respiratory distress syndrome, it has become a widely used model to investigate the effects of several agents on pathogenesis of lung injury. The antioxidant and anti-inflammatory properties of N-acetylcysteine (NAC) has been documented in many lung injury models. In this study, we evaluated the role of NAC in an OA-induced lung injury model by measuring myeloperoxidase (MPO) activity, malondialdehyde (MDA) and 3-nitrotyrosine (3-NT) levels in lung tissue. Five groups labelled Sham, NAC, OA, Pre-OA–NAC and Post-OA–NAC were determined. ALI was induced by intravenous administration of OA. The pre-OA–NAC group received iv NAC 15 min before OA infusion and the post-OA–NAC group received iv NAC 2 h after OA infusion. In both of the NAC treatment groups' blood and tissue samples were collected 4 h after OA infusion, independent from the time of NAC infusion. The MPO activity, MDA and 3-NT levels in lung homogenates were found to be increased in OA group and the administration of NAC significantly reduced tissue MPO, MDA and 3-NT levels ( p=0.0001). Lung histopathology was also affected by NAC in this OA-induced experimental lung injury model.