清脑宣窍方有效组分对缺血性脑中风大鼠血脑屏障上P-糖蛋白表达的影响

目的比较正常及缺血损伤时大鼠血脑屏障上转运蛋白中P-糖蛋白(P-gp)时征表达及清脑宣窍方有效组分对其表达的影响。方法线栓法制备缺血性脑中风大鼠模型,按照不同再灌注时间,模型组再分为0、0.51、、26、、122、4 h,采用免疫组织化学法观察正常组与模型组大鼠脑皮质及海马缺血区P-gp的表达。除假手术组外,缺血动物于术后1 d,随机分为模型组、清脑宣窍方有效组分高、中、低剂量组、维拉帕米组,并于造模后1～5 d灌胃给予相应药物。末次给药后,处死动物,取材,检测大鼠脑皮质及海马区P-gp的表达。结果免疫组织化学染色结果显示,正常组与模型组大鼠脑皮质及海马缺血区均可见P-gp阳性染色。免疫组化半定量分析表明,与正常组比较,不同再灌注时间模型组P-gp表达量均有显著性差异(P<0.05),皮质及海马缺血区P-gp表达量均降低;与模型组比较,清脑宣窍方有效组分各剂量组及维拉帕米组对缺血性脑中风大鼠脑皮质及海马区P-gp表达量明显降低(P<0.05)。结论在缺血性脑中风病理状态下,大鼠脑血脑屏障上转运蛋白P-gp存在一定的时征表达,而且从一定程度上反映了特定病理状态下由于蛋白表达的改变而引起的血脑屏障通透性的变化。清脑宣窍方有效组分对缺血性脑中风大鼠脑皮质及海马缺血区P-gp表达具有显著的抑制作用。

Influence of effective components of Qingnao Xuanqiao Fang on expression of BBB P-glycoprotein in rats with ischemia stroke

Objective To compare the time-series expression of P-glycoprotein(P-gp) in transportprotein in blood brain barrier(BBB) and influence of Qingnao Xuanqiao Fang on this expression in normal rats and rats with ischemia injure.Methods The rat model of ischemia stroke was established by using thread approach and then all rats were randomly divided into normal group and model group.The model group was given reperfusion at different time points(0 h,0.5 h,1 h,2 h,6 h,12 h and 24 h).The expression of P-gp was observed in ischemia areas of cortex and hippocampus in two groups by using immunohistochemistry assay.After one day and except of sham-operation group,the rats were randomly divided into model group,high-dose,mid-dose and low-dose effective components of Qingnao Xuanqiao Fang groups(high-dose group,mid-dose group and low-dose group),and verapamil group(Ver group),and they were given corresponding medicinal 1 day to 5 days after modeling.After the final medicinal giving,the rats were sacrificed for collecting samples and the expression of P-gp was detected in cortex and hippocampus.Result The results of immunohistochemistry assay showed that there was P-gp positive staining observed in the ischemia areas of cortex and hippocampus in normal group and model group.The results of hemi-quantitative analysis showed that the expression of P-pg had significant difference at different time points of reperfusion,and decreased in the ischemia areas of cortex and hippocampus in model group compared with normal group(P<0.05).There was significant difference in P-pg expression between model group and high-dose group,mid-dose group or low-dose group(P<0.05).The expression of P-pg decreased significantly in ischemia areas of cortex and hippocampus in high-dose group,mid-dose group,low-dose group and Ver group.Conclusion There is time-series expression of P-pg in BBB under the pathological condition of ischemia stroke,which reflects the changes of BBB permeability induced by changes of protein expression under a specific pathological status.The effective components of Qingnao Xuanqiao Fang has significant inhibitory effect on P-gp expression in the ischemia areas of cortex and hippocampus in rats with ischemia stroke.