创伤性脑损伤后高血糖对脑神经元损害作用的研究

The damage of hyperglycemia to the neurons following traumatic brain injury

目的:探讨大鼠创伤性脑损伤后高血糖对神经元的损害作用。方法:成年雄性SD大鼠随机分成正常对照组,创伤性脑损伤(Traumatic brain injury,TBI)组和胰岛素治疗组。每组伤侧及健侧皮层设立自身对照。分别测定各组伤前伤后各时间点血糖值,逆转录-聚合酶链反应(RT-PCR)测定伤后伤侧及健侧皮层葡萄糖转运蛋白3(Glucose transporter3,GLUT-3)基因表达,Western-blot法测定伤后伤侧及健侧皮层GLUT-3蛋白表达,免疫荧光法测定伤后各组伤侧及健侧皮层单个神经元神经特异性烯醇化酶(Neuronspecificenolase,NSE)表达量和NSE阳性染色细胞数,longa评分、平衡木试验、网屏试验综合评定伤后各组神经功能。结果:正常对照组各时间点血糖值,GLUT-3表达量,单个神经元NSE表达量及NSE阳性细胞数均未见明显变化;TBI组动物伤后血糖升高,伤侧皮层GLUT-3表达增加,单个神经元NSE表达量增加而NSE阳性染色细胞数明显减少神经瘫裂较重;胰岛素治疗组伤后血糖变化不明显,伤后12、24、48、72hGLUT-3表达量,单个神经元NSE表达量及NSE阳性染色细胞数均明显多于TBI组神经瘫裂程度明显轻于TBI组。各组健侧皮层GLUT-3和单个神经元NSE表达量,NSE阳性染色细胞数均未见明显变化。结论:TBI后高血糖可加重神经元损伤,其机制可能与TBI后高血糖抑制伤后神经元GLUT-3的表达,增加伤后神经元葡萄糖代谢障碍有关。

Objective：To explore the damage of hyperglycemia to the neurons.Methods：Adult male SD rats were randomly divided into 3 groups：normal control group,traumatic brain injury group and insulin treated group,the blood glucose concentrations of the rats were measured before injury and when they were killed.The method of RT-PCR was applied to detect the expression of GLUT-3 genes.The change of GLUT-3 protein was detected by western-blot.The changes of NSE and NSE positive-Staining cells were examined by immunofluorescence staining Longa,balance test and screen test score were used to assess neural fnuctional defect.Results：The blood glucose concentration only increased markedly in traumatic brain injury group.through the expression of GLUT-3 and single cell NSE increased in the injured cortical both in traumatic brain injury group and insulin treated group,there was much more expression of GLUT-3 and single cell NSE but less NSE positive-Staining cells and neural functional defect in the insulin treated group at 12,24,48,72 h after injury.Meanwhile there were no changes were found in the uninjured side of each group.Conclusion：The hyperglycemia after traumatic brain injury increased the damage to the neurons by decreasing the expression of GLUT-3.