Change of lung structure and expression of vascular endothelial growth factor protein in neonatal rats with hyperoxia

Aim To explore the changes of lung structure and expression of VEGF protein and factor Ⅷ,density of blood vessels and the correlation.Methods Seventy-two Sprague-Dawley neonatal rats were randomly continually exposed to hyperoxia(FiO2=95%)or room air(FiO2=21%,control group)30 minutes after birth.Histological study of the lung tissue and radical alveoli count(RAC)were carrided out,and VEGF protein and factor Ⅷ expressed in the lungs were determinded by immunohistochemical methods respectively 3,7 and 14 days after birth.Results Alveolarization gradually makes progress,radical alveolar counts and VEGF protein and factor Ⅷ expression increased with increasing postnatal age in the control group.In the hyperoxia exposure group alveolarization were arrested,The expression of RAC and VEGF protein and factor Ⅷ was significantly reduced.The level of VEGF was correlated with that of factor Ⅷ.Conclusions VEGF is associated with lung development in neonatal rats.The expression of VEGF protein and factor Ⅷ in lungs of neonatal rats is inhibited after exposed to hyperoxia.