亚硒酸钠联合高压氧对创伤性颅脑损伤大鼠模型治疗作用的机制研究

The mechanism of sodium selenite and hyperbaric oxygen on the therapeutic effect of traumatic brain injury rats model

目的探讨亚硒酸钠联合高压氧对颅脑损伤大鼠模型治疗作用的机制。方法 30只雄性SD大鼠随机分为正常组、模型组(脑损伤组)、联合组(亚硒酸钠联合高压氧处理组)。然后建立大鼠闭合性颅脑损伤模型,以NSS评分将损伤程度统一为中度颅脑损伤程度。有高压氧的组别伤后0.5、24.0、48.0h做高压氧治疗,各组均以72h统一留取标本,组织匀浆检测MDA、SOD以及GSH的含量;提取组织总RNA,real-time PCR检测bcl-2以及caspase-3mRNA的表达;免疫组化检测皮质区和海马区的caspase-3表达及分布。结果 (1)与正常组相比,模型组MDA含量大量增加(P<0.05),SOD及GSH的含量均显著降低(P<0.05);与模型组相比联合组的大鼠MDA含量均显著下降,SOD和GSH含量均显著升高(P<0.05)。(2)与正常组相比,模型组bcl-2的mRNA表达明显降低(P<0.05),而caspase-3的mRNA则显著增加(P<0.05);与模型组相比,联合组的大鼠均提高了bcl-2的mRNA表达(P<0.05),降低了caspase-3的mRNA的表达(P<0.05)。免疫组化结果也显示在皮质区和海马区联合组的大鼠显著减少了caspase-3的阳性表达。结论亚硒酸钠联合高压氧治疗创伤性颅脑损伤(TBI)是通过降低氧自由基的生成,增加自由基清除剂的产生和凋亡抑制因子bcl-2的表达以及抑制细胞凋亡蛋白caspase-3的表达而实现的。

Objective To study the mechanisms of sodium selenite in combination with hyperbaric oxygen treatment of traumatic brain injury in rats.Methods 30 male SD rats were randomly divided into normal control group,model group(brain injury group),sodium selenite combined with hyperbaric oxygen treatment group.Then the establishment of rat model of closed head injury,injury severity score in NSS will be unified as a moderate degree of traumatic brain injury.Hyperbaric oxygen group rats received hyperbaric oxygen therapy in 0.5,24.0,48.0 hours after injury.All the rats were sacrificed after 72 hours,then detected the content of MDA,SOD and GSH in tissue homogenate;extracted of total RNA,real-time PCR analysised the expression of the bcl-2 and caspase-3 mRNA expression;immunohistochemical methods to detect the Caspase-3 expression and distribution in cortex and hippocampus.Results(1)Compared to the normal control group,content of MDA in model group increased significantly(P<0.05),SOD and GSH contents were significantly decreased(P<0.05),compared to the model group,MDA contents were significantly decreased,SOD and GSH contents were significantly elevated in the combined group(P<0.05).(2) compared to the normal group,model group,bcl-2 mRNA expression were significantly decreased and caspase-3 mRNA expression were significantly increased(P<0.05),compared to the model group,the rats in combined group were improved in bcl-2 mRNA expression,reduction of caspase-3 mRNA expression.Immunohistochemical results also showed that in the cortex and hippocampus,the positive expression of caspase-3 were significantly reduced(P<0.05),in combined group rats.Conclusion Sodium selenite combined with hyperbaric oxygen treat of TBI in rats are through the generation of oxygen free radical scavengers of free radicals,increase production and apoptosis inhibitory factor bcl-2 expression and inhibition of apoptosis protein caspase-3 expression pathways.