Effects of xenon on the expression of EphB4 and EphrinB2 mRNA in neonatal rats with white matter damage / 中国新生儿科杂志

ABSTRACT

Objective To investigate the pathogenesis of white matter damage (WMD) and the effects of xenon intervention on the expression of EphB4 and EphrinB2 mRNA in the brain tissue of neonatal rats.Method Three-day-old SD rat pups (n =96) were randomly assigned into sham group (n =24),model group (n =24),xenon intervention group 1 (n =24) and xenon intervention group 2 (n =24).The WMD model was established by injected of lipopolysaccharide (LPS) 0.05 mg/kg combined with ligation of the right carotid artery for 1 h in the last three groups.Rats in xenon intervention group 1 inhaled 50％ xenon immediately for 3 h after modeling,while rats in xenon intervention group 2 inhaled 50％ xenon for 3 h at 2 h after modeling.After the completion of xenon intervention,6 rat pups in each groups were sacrificed at 0 h,24 h,48 h and 72 h.The pathologic examination of periventricular tissue was conducted with hematoxylin-eosin staining (HE) and the expression of EphB4 and EphrinB2 mRNA was assayed by real-time quantitative polymerase chain reaction (RT-PCR).Statistical analysis was then performed.Result (1)The structure of white matter in model group became loose,band net-like,with significant nucleus pyknosis.The pathological damages in xenon intervention group 1 and 2 were lighter at 24 h,48 h and 72 h than model group,with less karyopycnosis.(2) Compared with the sham group,the expressions of EphB4 and EphrinB2 mRNA at 0 h,24 h,48 h and 72 h were significantly higher in the model group and xenon intervention group 1 and 2 (P ＜ 0.05),except for the EphB4 mRNA in xenon intervention group 1 at 72 h (P ＞ 0.05).The expressions of EphB4 and EphrinB2 mRNA at each time point in xenon intervention group 1 and 2 were decreased significantly than the model group (P ＜ 0.05),except for the EphB4 mRNA in xenon intervention group 2 at 72 h (P ＞ 0.05).However,there was no statistically significant difference on EphB4 and EphrinB2 mRNA between two xenon intervention groups at each time point (P ＞ 0.05).Conclusion The expression of EphB4 and EphrinB2 mRNA are appreciably increased in brain tissue of neonatal rats with WMD,which indicates the reactive angiogenesis.The intervention with xenon may play a neuroprotective role through reducing the expressions of EphB4/EphrinB2 mRNA and angiogenesis,and early intervention may be better.