高压氧治疗对急性脑损伤大鼠神经行为学及ERK1／2表达的影响

Effects of hyperbaric oxygen treatment on expression of ERK1/2 and neurological function in rats with traumatic brain injury

目的探讨高压氧治疗对急性创伤性脑损伤（traumatic brain injury，TBI）大鼠神经行为学及细胞外信号调节激酶（extra—cellular signal regulated kinase1／2，ERKL／2）表达的影响，为临床应用高压氧治疗TBI提供实验依据。方法SD大鼠24只，随机数字表法分为假手术组、TBI组和高压氧治疗组，每组8只。假手术组仅行开颅手术不致TBI；TBI组采用Alice打击法以50g重锤自40cm垂直高度自由落体打击制作大鼠急性TBI模型；高压氧组在TBI基础上行高压氧治疗（1次／d，连续10d）。各组大鼠于处理后14d进行神经功能损伤评分（neurological severity scores，NSS）。随后处死动物，获取脑组织，用RT—PCR方法测定脑组织内ERK1／2mRNA的表达。免疫组化染色确定ERK表达的细胞定位，吸光度分析了解ERK蛋白变化。结果与TBI组比较，高压氧治疗组14dNSS评分明显降低（P〈0．01）。同时，高压氧治疗组ERK1／2mRNA和蛋白表达明显降低（P〈0．05）。结论高压氧治疗能明显降低急性TBI大鼠NSS评分及ERK1／2表达，提示高压氧治疗可能通过下调ERK1／2表达改善神经功能。

Objective To explore the effects of hyperbaric oxygen （HBO） treatment on expression of extra-cellular signal regulated kinase 1/2 （ERK1/2） and neurological function in acute traumatic brain injury （TBI） rats so as to offer trial support for clinical application of HBO in TBI. Methods Twenty-four adult Sprague-Dawley rats were randomly divided into sham-operation group, TBI group and HBO treatment group, with eight rats per group. The sham-operation group was free from TBI but skull was opened only but the TBI group was subjected to TBI according to Alice method. The HBo treatment group was treated with HBO for 10 days （one time per day） after TBI operation. On day 14, NSS rating was performed in all rats. Then, the rats were sacrificed and cortex of which was obtained to measure the expression of ERKI/2 by using reverse transcription-polymerase chain reaction （RT-PCR）. The localization of the expression of ERK was detected by immunohistochemical staining and the changes in ERK protein was analyzed by optical density. Results The NSS score in the HBO group was significantly decreased at day 14 after HBO treatment （P 〈0.01 ） and the expression of ERK1/2 in HBO group was also significantly decreased （P 〈 0.05） in comparison with the TBI group. Conclusions HBO treatment can significantly decrease NSS score and expression of ERK1/2 in acute TBI rats, indicating that HBO may improve neurological function through down-regulating expression of ERK1/2.