高压氧治疗创伤性脑损伤的效用及机制研究

目的:研究高压氧(HBO)对大鼠创伤性脑损伤(TBI)治疗效用并观察脑组织星形胶质细胞活化及胶质细胞源性神经营养因子(GDNF)和神经生长因子(NGF)表达的变化以探讨作用机制。方法:SD雄性大鼠54只,随机分为3组(n=18):假手术组、TBI组和HBO治疗组。采用Feeney法建立大鼠TBI模型,假手术组只开放骨窗,不予打击。HBO治疗组大鼠于脑损伤后6 h采用动物高压舱,以3ATA压力纯氧治疗60 min。TBI后48 h测量神经功能,然后分离脑组织,其中18只用干湿法测定脑含水量;18只脑组织用于切片,部分进行尼氏染色后作形态学观察,部分进行免疫组织化学染色,检测星形胶质细胞标记物胶质纤维酸性蛋白(GFAP)、波形蛋白(vimentin)与S100蛋白的表达;另18只大鼠取伤侧脑半球,进行Western blot分析,观察GDNF和NGF的表达。结果:HBO治疗能减轻神经功能障碍,降低脑含水量,减少海马部位神经细胞丢失,进一步激活损伤侧皮质与海马部位GFAP、vimentin与S-100阳性表达星形胶质细胞,促进损伤侧脑组织GDNF与NGF的表达。结论:HBO对创伤性脑损伤有较好治疗效果,其机制与上调GDNF和NGF的表达有关。

Therapeutic efficacy of hyperbaric oxygen on traumatic brain injury in the rat and the underlying mechanisms

Objective: To investigate the effects of hyperbaric oxygen(HBO) treatment on the activation of astrocytes and the expression of glia-derived neurotrophic factor(GDNF) and nerve growth factor(NGF) in the brain after traumatic brain injury(TBI).Methods: 54 male SD rats were randomly divided into three groups(n=18): sham-operated,TBI and HBO treatment groups.TBI was induced with Feeney’s method,bone window was opened without strike on the brain tissue in the sham-operated group.HBO group rats received HBO treatment for 60 min in the hyperbaric chamber containing O2 100% at 3 ATA.When neurological functions were measured 48 h after TBI,rats were decapitated,the brain water content of 18 rats was measured,18 brains were sliced for the morphological observation after Nissl staining and for the immunohistochemistry staining of astrocyte markers glial fibrillary acidic protein(GFAP),vimentin and S100,and the other 18 brains of injured side were used for Western blot analysis of GDNF and NGF.Results: HBO treatment reduced the neurological deficit,brain water content and hippocampal neuronal loss.In the observed cortex and hippocampal area astrocytes were activated,the cell number of positive expression of astrocyte markers GFAP,vimentin and S100 was increased,and the expression of GDNF and NGF was elevated after TBI.However,these indices were all enhanced further after the HBO treatment.Conclusion: It is suggested that HBO may be an effective therapy for TBI and upre-gulation of the expression of GDNF and NGF may underly the effect of HBO.