高频重复经颅磁刺激预处理对全脑缺血大鼠再灌注损伤的影响

Effects of high frequency repetitive transcranial magnetic stimulation preconditioning on rats after cerebral ischemia-reperfusion injury

目的研究高频重复经颅磁刺激(rTMS)预处理对脑缺血再灌注大鼠神经功能缺损、血脑屏障以及脑源性神经营养因子(BDNF)、磷酸化酪氨酸激酶受体B(pTrkB)的影响。方法将40只雄性SD大鼠按随机区组法分为对照组、模型组、rTMS预刺激3次组、rTMS预刺激7次组,每组10只。采用改良四血管阻断法(4-VO)制作全脑缺血再灌注损伤模型,改良神经功能缺损评分(mNSS)测量神经功能缺损,Western blotting检测脑组织BDNF和pTrkB蛋白表达。结果rTMS预处理3次组和7次组大鼠的mNSS评分分别为(7.42±1.76)分、(5.38±1.91)分,较模型组的(9.87±1.23)分明显降低,差异均有统计学意义(P<0.05);rTMS预处理7次组伊文思蓝含量为(17.538±1.984)μg/g,较模型组的(29.829±8.633)μg/g明显下降,BDNF和pTrkB蛋白表达分别为23.247±1.782、16.876±1.873,较模型组的12.093±1.289、4.211±0.078明显增加,差异均有统计学意义(P<0.05);rTMS预处理3次组大鼠的BDNF和pTrkB蛋白表达分别为16.683±1.492、8.830±1.142,较模型组的12.093±1.289、4.211±0.078明显增加,差异均有统计学意义(P<0.05);rTMS预处理7次组大鼠的mNSS评分为(5.38±1.91)分,较rTMS预处理3次组的(7.42±1.76)分明显降低,BDNF和pTrkB蛋白表达分别为23.247±1.782、16.876±1.873,较rTMS预处理3次组的16.683±1.492、8.830±1.142明显增加,差异均有统计学意义(P<0.05)。结论高频rTMS预处理可以改善全脑缺血再灌注大鼠血脑屏通透性,上调BDNF和pTrkB蛋白表达,降低缺血再灌注神经功能损伤。

Objective To study the effect of high frequency repetitive transcranial magnetic stimulation(rTMS)preconditioning on neurological deficit,brain-brain barrier(BBB),brain-derived neurotrophic factor,and phosphorylated tyrosine kinase receptor B of rats after cerebral ischemia-reperfusion injury.Methods With randomized blocks design,forty male SD rats were divided into control group,model group,rTMS pretreatment three times group,and rTMS pretreatment seven times group,with ten rats in each group had.The global cerebral ischemia rat models were made by modified four-vessel occlusion.Neurological deficit was assessed with modified Neurological Severity Score(mNSS).Western blotting was used to detect the expression of brain-derived neurotrophic factor and phosphorylated tyrosine kinase receptor B of ischemic brain tissue.Results The mNSS score in the rTMS pretreatment three times group and seven times were(7.42±1.76)points,(5.38±1.91)points,respectively,which were significantly lower than(9.87±1.23)points in the model group(all P<0.05).The evans blue content in rTMS pretreatment seven times group was(17.538±1.984)μg/g,which was significantly lower than(29.829±8.633)μg/g in the model group(P<0.05).The expression of BDNF and pTrkB in rTMS pretreatment seven times group were 23.247±1.782 and 16.876±1.873,respectively,which were significantly higher than 12.093±1.289 and 4.211±0.078 in the model group(all P<0.05).The expression of BDNF and pTrkB in rTMS pretreatment three times group were 16.683±1.492 and 16.876±1.873,respectively,which were significantly higher than 12.093±1.289,4.211±0.078 in the model group(all P<0.05).The mNSS score in the rTMS pretreatment seven times group was 5.38±1.91,significantly lower than 7.42±1.76 in the rTMS pretreatment three times group(P<0.05).The expression of BDNF and pTrkB in the rTMS pretreatment seven times group were 23.247±1.782 and 16.876±1.873,respectively,which were significantly higher than 16.683±1.492 and 8.830±1.142 in the rTMS pretreatment three times group(all P<0.05).Conclusion High frequency rTMS preconditioning can improve the permeability of BBB,upregulate the expression of BDNF and pTrkB,and reduce neurological impairment in rats after cerebral ischemia-reperfusion injury.