【摘要】 目的:观察黄芩素甙对脑缺血后大鼠海马CA1区神经元GluR2蛋白及其mRNA表达的影响。方法:SD雄性大鼠25只,体重250～300g,随机分成5组(n=5):假手术组(Ⅰ组)、缺血再灌注2天组(Ⅱ组)、缺血再灌注4天组(Ⅲ组)、黄芩素甙2天组(Ⅳ组)和黄芩素甙4天组(Ⅴ组)。后两组在缺血前30min给予黄芩素甙45mg/kg腹腔注射,其余各组在相应时间点给予等容量生理盐水。采用四血管阻断法制作大鼠全脑缺血再灌注模型,脑缺血时间10min。再灌注后2和4天再次麻醉动物,断头处死并分离海马CA1区,采用Western blot和RT-PCR技术分别测定GluR2及其mRNA的表达情况,并计算各自条带的灰度值。结果:与Ⅰ组比较,Ⅱ组和Ⅲ组的GluR2及其mRNA表达下调(P<0.01);与Ⅱ组和Ⅲ组比较,Ⅳ组和Ⅴ组的GluR2及其mRNA表达上调(P<0.01)。结论:黄芩素甙可能通过抑制脑缺血后海马CA1区神经元GluR2蛋白及其mRNA的下调而发挥脑保护作用。更多还原

【Abstract】 Objective:To investigate the effects of breviscarpin on GluR2 protein and mRNA expression in hippocampal CA1 neurons of rats following transient forebrain ischemia.Methods:Twenty-five male SD rats weighed from 250～300 g were randomly divided into 5 groups(n=5 each):groupⅠ(sham operation),groupⅡ(ischemia /reperfusion for 2 days),group Ⅲ(ischemia /reperfusion for 4 days),group Ⅳ(breviscarpin combined with ischemia/reperfusion for 2 days),groupⅤ(breviscarpin combined with ischemia/reperfusion for 4 days).The rats of Ⅱ,Ⅲ,Ⅳand Ⅴgroup were subjected to transient but severe forebrain ischemia by permanently occluding the vertebral arteries and 24 hours later temporarily occluding the common carotid arteries for 10 minutes.GroupⅠ animals were treated identically,except that the carotid arteries were not occluded.The rats of Group Ⅳ and Ⅴ were injected with breviscarpin(45 mg /kg) in abdominal cavity at 30 min before ischemia.The other groups were injected with equal 0.9% NaCl saline at the corresponding time.For quantization of GluR2 protein /GluR2 mRNA expression,rats were anesthetized and decapitated and the hippocampal CA1 were removed 2 days and 4 days after cerebral ischemia.GluR2 protein expression was assessed by Western Blot.RT-PCR was performed to assess the expression of GluR2 mRNA.The density of the bands was analyzed.Signal intensities were normalized against the internal standard(Western blot by GAPDH,RT-PCR by β-actin).Results:The GluR2 protein and mRNA expressions of group Ⅱand Ⅲ were both lower than those of groupⅠ(P < 0.01).But the expressions of group Ⅳ and Ⅴwere higher than those of groupⅡand Ⅲ at the corresponding time(P < 0.01).Conclusion:Breviscarpin attenuates down-regulation of GluR2 protein and mRNA after forebrain ischemia,which may be one of the inportant reasons rescuing hippocampal CA1 neurons after forebrain ischemia by breviscarpin.更多还原