Effects of Hyperoxia on the Proliferation of Lung Fibroblasts and Synthesis of Type I Collagen in Newborn Rats with Chronic Lung Disease

Objective To explore the proliferation of lung fibroblasts and synthesis of type Ⅰ collagen in newborn rats with hyperoxiainduced chronic lung disease(CLD).Methods Full-term newborn rats were randomly divided into air control group and hyperoxia group.The rat pups were killed on postnatal days 3,7,and 14.The primary culture of lung fibroblasts was performed,and the cell cycle was detected by flow cytometry.The distribution of PCNA protein in lung fibroblasts was measured by immunohistochemistry.The expression of type Ⅰ collagen was determined by ELISA.Results In hyperoxia group,the proliferation of lung fibroblasts was promoted on postnatal days 7 and 14.Compared with air control group,the percentage of G1 phase cell was significantly higher and the expression of type Ⅰ collagen significantly increased in hyperoxia group on postnatal days 7 and 14(P 0.05).Conclusion Hyperoxia induces excessive proliferation of lung fibroblasts and increases synthesis of type Ⅰ collagen in newborn rats,leading to pulmonary fibrosis finally.