Expressions of VEGF and Ang-1 in neonatal rats with hyperoxia-induced BPD and its effects on lung development

Objective To investigate the expressions of VEGF and Ang-1 in neonatal rats with hyperoxiainduced BPD and its effects on lung development. Methods 48 SD neonatal rats(2 or 3 days old) were randomly divided into two group and raised under hyperoxia or air for 1, 3 and 7 days, respectively. Real-time RT-PCR and Western blot were used to determine the level VEGF and Ang-1 mRNAs and proteins in lung tissues of the two groups. HE staining was used to observe the changes of lung morphology. Results The levels of VEGF and Ang-1 mRNAs in the lung on the 7th day in the control group were 0.722 ± 0.372 and 0.828 ± 0.462, respectively, and those in hyperoxia group were 0.239 ± 0.293 and 0.327 ± 0.184, respectively. The levels of VEGF and Ang-1 proteins on the 7th day in the control group were 0.632 ± 0.289 and 0.573 ± 0.436, respectively, and those in hyperoxia group were 0.358 ± 0.128 and 0.204 ± 0.068, respectively. Comparing to the control group, the levels of VEGF and Ang-1 mRNAs and proteins on the 7th days significantly decreased in the hyperoxia groups(P 0.05). The lung tissues of the hyperoxia group display dysplastic features with, alveolar simplification, reduced alveolar numbers and retardation on microvascular development. Conclusion VEGF and Ang-1, functioning as an important regulators for pulmonary vascular development, are involved in the pathogenesis of BPD and the lung development.