The Differences Between Hyperbaric Oxygen And High Concentrations Oxygen On The Retina And Lung Injuries In Neonatal Mice

Background: Using high concentration oxygen (HO) repeatedly could induce the retina and lung injuries, in which VEGF played an important role, but hyperbaric oxygen did not have such toxicity.Objective: To investigate the toxicity and the expression of VEGF in the retina and lung of normal neonatal mice after HBO and HO intervention, and investigate the toxicity of HO after VEGF was blocked by SU-5416.Methods: 1. Kun Ming (KM) mice were divided into four parts : (1) Control group (CON); (2) HBO group (HBO); (3) HO group (HO); (4) HO after the intervention of SU-5416 group (SU). The HBO group was administered with 3.0 ATA pressure of air and oxygen once per day which persisted a series of 5 days and then rose under normal pressure. The HO group was given high concentration oxygen (88%-92%) inhalation for 5 days and then raised under normal air. The SU group was injected with SU-5416 of a single-dose and was then exposed to the same as the HO group. The control group was given no intervention. All mice were killed at 17 days old. 2. Observate new retinal vessels of flattening retina on the slide by Chinese ink staining and pathologic examination for eyeballs and lungs under light microscope. Immunohistochemistry of VEGF: to quantitative the expression of VEGF in retina and lung.Results: Compared with the CON group, the number of nuclei of the new vessels of the HO group is much higher, but it was almost the same in the HBO group. The SU group, which was higher than the CON group, was much lower than the HO group. The changes of retinal vessels of flattening retina on the slide showed that the HO group increased significantly while there were fewer changes in the HBO and SU group. Immunohistochemistry of VEGF in retina showed the expression of VEGF, which increased in the HO group, was not so visible in the HBO and SU group. The ratio of the area of pulmonary alveoli of the HO group was lowest, for the structure of alveoli pulmonis was irregular, the normal structure disappeared and intralobular interstitial thickening was conspicuous. It was lower in the HBO and SU group than the CON group, but much higher than the HO group. Immunohistochemistry of VEGF in lung showed that the expression of VEGF decreased in the HO group compared with the CON group. There were no significant differences between the HBO and CON group. The expression decreased in the SU group, but it increased a lot compared with the HO group.Conclusions: 1) HO stimulated retina neovascular proliferation and caused pulmonary injury in normal neonatal mice which related to the expression changes of VEGF. 2) HBO did not induce the retina and lung injuries or change the expression of VEGF in normal neonatal mice. 3) SU-5416 had a protective effect on the HO-induced damages and alleviated both the increased expression of VEGF in retina and the decreased expression in lung of normal neonatal mice.