早期高压氧对缺血缺氧性脑损伤新生大鼠脑神经保护的效果探讨

Study on the effect of early hyperbaric oxygen in protecting brain nerves of neonatal rats with hypoxic ischemic brain damage

目的探讨早期高压氧对缺血缺氧性脑损伤(HIBD)新生大鼠脑神经保护的效果。方法将7日龄新生Wistar大鼠120只随机分为假手术组、HIBD组、高压氧组,每组各40只。将高压氧组再随机分为早期高压氧亚组和晚期高压氧亚组,每亚组各20只。对所有大鼠建立HIBD模型后(假手术组采用假手术处理),早期高压氧亚组在建模后1h内,晚期高压氧亚组在建模后48h实行高压氧治疗(2ATA,每次90min,24h1次,连续治疗7d)。各亚组治疗结束后处死大鼠,假手术组与HIBD组处死等量大鼠。利用免疫组织化学法对大鼠海马中神经巢蛋白(Nestin)的含量进行检测,利用Morris水迷宫实验对大鼠学习记忆功能进行检测。结果假手术组Nestin阳性细胞检出数量为(10.26±1.37)个/HP,早期高压氧亚组Nestin阳性细胞检出数量为(15.82±2.19)个/HP,晚期高压氧亚组Nestin阳性细胞检出数量为(32.64±4.83)个/HP,HIBD组Nestin阳性细胞检出数量为(36.18±4.02)个/HP。高压氧组和HIBD组Nestin阳性细胞检出数量显著高于假手术组,差异有统计学意义(P<0.05),晚期高压氧亚组显著高于早期高压氧亚组,差异有统计学意义(P<0.05),晚期高压氧亚组与HIBD组比较,差异无统计学意义(P>0.05);4组平均逃逸潜伏期差异有统计学意义(F=24.18,P<0.05),假手术组<早期高压氧组<晚期高压氧组<HIBD组;假手术组、早期高压氧组和晚期高压氧组3组大鼠在搜索耗时和搜索路程上组间比较,差异有统计学意义(F=21.05,P<0.05),假手术组>早期高压氧组>晚期高压氧组,而晚期高压氧组和HIBD组组间比较差异无统计学意义(P>0.05),各组搜索速度组间比较,差异无统计学意义(P>0.05)。结论早期高压氧对HIBD脑损伤具有保护功能,Nestin蛋白可能参与了脑神经的修复过程,早期高压氧还对HIBD引起的远期学习记忆功能障碍有改善作用。

Objective To investigate the effect of early hyperbaric oxygen（HBO）in protecting brain nerves of neonatal rats with hypoxic ischemic brain damage（HIBD）.Methods A total of 120 7-day old neonatal Wistar rats were randomly divided into sham operation group（control group）,hypoxic ischemic brain injury group（group HIBD）and hyperbaric oxygen group（HBO group）,with 40 rats in each group.The HBO group was randomly divided into early hyperbaric oxygen subgroups（EHBO subgroup）and late hyperbaric oxygen subgroups（LHBO subgroup）,with 20 rats in each group.After establishing the HIBD model for all rats（control group with sham operation）,hyperbaric oxygen treatment was performed in EHBO subgroup after 1h,and in LHBO subgroup after 48h（2ATA,every 90 minutes,24hours once,continuous treatment of 7day）.After treatment,the rats in subgroups were killed,and the same number of rats in the control group and HIBD group were also killed.Hippocampus Nestin in the nerve of rat was determined using immunohistochemical method,and learning and memory function in rats were tested using the Morris water maze test.Results In the control group Nestin positive cell detection rate was（10.26±1.37）/HP,in EHBO subgroup it was（15.82±2.19）/HP,LHBO subgroup（32.64±4.83）/HP,HIBD group（36.18±4.02）/HP.The detection rate of Nestin positive cells in the HBO group,and HIBD group was significantly higher than that of the control group（P〈0.05）,and in the LHBO subgroup it was significantly higher compared with that of the EHBO subgroups（P〈0.05）,while the LHBO subgroup and HIBD group had no significant difference（P〉0.05）;the four groups had significant differences in average EL（F=24.18,P〈0.05）;the rats in control group,EHBO and LHBO group had significant difference in the search time and search distance（F=21.05,P〈0.05）,but there was no significant difference between LHBO and HIBD groups and among the groups in search time（P〉0.05）.Conclusion Early BHO has protective effect on brain injury;Nestin protein may be involved in the repair of brain nerves;early HBO can improve the future learning and memory function which is impaired by HIBD.