Effect of inhaled N-acetylcysteine on the oxidative stress and content of proteases in lungs of newborn guinea pigs exposed to hyperoxia

Lung-protective pharmacotherapies preventing development of bronchopulmonary dysplasia (BPD) in infants are widely investigated. The aim of this study was to evaluate the influence of inhaled N-acetylcysteine (NAC) on the oxidative and protease imbalance in lungs of newborn guinea pigs under prolonged hyperoxia. The studied groups included: “hyperoxia” (n=12, 70% O2, 14 days), “hyperoxia+NAC” (n=6, 250 mg/kg of NAC introduced by nebulizer on alternate days on hyperoxia exposure), “control” (n=12, room air). Hyperoxia exposure resulted in enhanced production of reactive oxygen species (ROS) by bronchoalveolar lavage cells, 1,9-fold increased level of products reacting with thiobarbituric acid (TBARP), low glutathione peroxidase activity and glutathione (G-SH) in bronchoalveolar lavage fluid (BALF) (30% and 68% of controls respectively); elevated alpha1-antitrypsin (A1-AT), neutrophil elastase and matrix metalloproteases MMP2 and MMP9 in lung homogenates (141%, 286%, 132%, and 176% of controls respectively) (for all p