高氧致新生大鼠急性肝损伤及对肝组织中Nrf2表达的影响

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、14 d 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、14 d与高氧组4 d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。

Liver Injury and Nrf2 Expression in Neonatal Rats with Hyperoxia

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 4 d, 7 d, 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 7 d and 14 d than those on 4 d (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.