F Xu, TF Fok, E Yung, JA Yin, KF To

Abstract

In a preterm rat model of hyperoxia-induced lung injury, we studied the lung antioxidant enzyme (AOE) activities and gene expression. After seven days of continuous exposure to >95% oxygen, severe injuries were found in the lungs with inflammation and edema. Manganese superoxide dismutase (MnSOD) mRNA level and SOD activities in lung tissues were significantly elevated when compared to the room air controls (p=0.002, p<0.001). There was no significant increase in the levels of glutathione peroxidase (GP), catalase (CAT) or their gene expression. These findings show that in the premature rat lung, oxygen-induced damage is associated with upregulation of SOD gene expression and increased SOD activities.