清热化瘀Ⅱ号方对脑缺血预处理大鼠MAP1B表达的影响

Effect of Qingre Huayu PrescriptionⅡ on the Expression of Microtabule Associated Protein 1B after Focal Ischemic Preconditioning in Rats

目的观察清热化瘀Ⅱ号方对脑缺血预处理再灌注后大鼠脑内微管相关蛋白1B(MAP1B)的影响,探讨其对缺血性脑损伤神经元的保护作用机制。方法 SPF级SD大鼠126只,随机分为正常对照组(6只)、假手术组(30只)、脑缺血再灌注组(30只)、脑缺血预处理组(30只)、清热化瘀Ⅱ号方组(30只),除正常对照组外每组按照再灌注后3h、6h、12h、24h、48h5个时间点平均分为5个亚组,采用二次线栓法制备大鼠局灶性脑缺血预处理模型,用RT-PCR法检测各时间点MAP1B蛋白表达变化。结果正常对照组和假手术组均有MAP1BmRNA表达,但差异无统计学意义(P>0.05);脑缺血再灌注组在12h时缺血侧海马区MAP1BmRNA表达至高峰,随再灌注时间延长其表达逐渐下降,但与正常对照组相比仍明显升高(P<0.01);与脑缺血再灌注组相比,脑缺血预处理组在12h、24h、48h时表达均有明显的升高(P<0.01);与脑缺血预处理组相比,清热化瘀Ⅱ方组在48h时表达水平进一步增高(P<0.05)。结论缺血预处理可能通过上调MAP1B的表达发挥神经保护的作用,而清热化瘀Ⅱ号联合缺血预处理进一步增强其保护作用。

Objective To investigate the effect of Qingre Huayu prescription Ⅱ（QHPⅡ） on the expression of microtabule associated protein 1B（MAP1B） after focal ischemic preconditioning in rats.Methods One hundred and twenty-six Sprague-Dawley（SD） rats with healthy specific pathogen free（SPF） were randomly divided into five groups：Normal control group,sham operation（SO） group,ischemia-reperfusion（I/R） group,brain ischemia preconditioning（BIP） group and QHP Ⅱ group.Except the normal control group,other groups was further divided into 5 subgroups according to 3 h,6 h,12 h,24 h,and 48 h after I/R.The BIP models were established by twice occlusion with thread.The changes of MAP1B mRNA expression were measured by real-time polymerase chain reaction（RT-PCR）.Results In both the normal control group and SO groups,a few cells with expression of MAP1B mRNA appeared（P＆gt;0.05）.The expression of MAP1B mRNA on the ischemic side in hippocampus was strongest at 12 h.With the prolongation of I/R duration,the expression of MAP1B mRNA had decline trend in the I/R group.Comparing with the normal control group,the expression of MAP1B mRNA were increased significantly in I/R groups（P＆lt;0.01）.As compared with I/R groups,the expression of MAP1B mRNA at 12 h,24 h and 48 h after operation in BIP group were increased significantly（P＆lt;0.01）.QHPⅡ treatment could further increase the expression levels（P＆lt;0.05） compared with 48 h in BIP group.Conclusion Brain ischemia preconditioning might play a neuroprotective role through regulating MAP1B expression during cerebral ischemia and reperfusion.QHPⅡ had synergistic action on brain ischemic preconditioning in protecting neurons through up regulating the expression of MAP1B in rats.