高氧致新生大鼠急性肝损伤及对肝组织中Nrf2表达的影响

Liver Injury and Nrf2 Expression in Neonatal Rats with Hyperoxia

目的研究持续吸入高浓度氧气对新生大鼠的肝损伤,探讨转录因子NF-E2相关因子2(Nrf2)在损伤肝组织中的动态表达及意义。方法足月SD新生大鼠100只随机分为空气组(N组)和高氧组(O组),每组50只。高氧组出生后立即置入氧体积分数>95%的持续高氧环境中饲养,正常对照组则持续空气中饲养。两组分别于暴露高氧或空气中4、7、14d随机抽取8只,麻醉后取肝组织,比较两组肝细胞凋亡指数,检测Nfr2在肝组织中的表达。结果肝细胞凋亡指数及Nrf2的表达于各时点高氧组均高于正常组(P<0.01)。高氧组7、14d与高氧组4d比肝细胞凋亡指数及Nrf2的表达差异有统计学意义(P<0.01)。结论持续高浓度氧气吸入可致新生大鼠肝损伤,Nrf2表达增加,启动机体自身抗氧化机制。

Objective To investigate the effect of continuous exposure to hyperoxia on livers and changes in nuclear factor erythroid 2-related factor 2（Nrf2）expression in hepatic tissues in neonatal rats.Methods 100 neonatal Sprague-Dawley rats were randomized divided into hyperoxia group（FiO2=95%,O group）and normal control group（FiO2=21%,N group）immediately after birth.Hepatic apoptotic index and Nrf2 expression were detected by immunohistochemical methods on 4d,7d,and 14 d.Results Rats with hyperoxia had higher levels of hepatic apoptotic index and Nrf2 expression compared with the controls（P〈0.01）.The levels of hepatic apoptotic index and Nrf2 expression in rats with hyperoxia were higher on 7dand 14 dthan those on 4d（P〈0.01）.Conclusion Continuous exposure to hyperoxia could result in hepatic damage to neonatal rats,with increased expression of Nrf2 as a mechanism of anti-oxidant.