摘要
目的探讨藻蓝蛋白对大鼠局灶性脑缺血再灌注后COX-2及COX-2 mRNA表达的影响。方法用线栓法制作大鼠左侧大脑中动脉阻塞再灌注模型(MCAO),分别对假手术组、模型对照组、藻蓝蛋白组进行神经功能缺失评分,用TTC染色法测量脑梗死体积,应用免疫组化和原位杂交技术分别观察脑缺血再灌注后不同时间点COX-2及COX-2 mRNA在神经元中的表达情况。结果(1)假手术组和模型对照组非缺血侧脑组织可见到少量COX-2阳性细胞。模型对照组COX-2阳性细胞主要位于缺血周围区,而缺血中心区仅有少量阳性细胞出现,缺血再灌注后6h COX-2阳性细胞数开始增加,至再灌注24 h达高峰,2 d后阳性细胞逐渐减少,至14 d时仍有表达,略高于假手术组。藻蓝蛋白组COX-2阳性细胞也主要位于缺血周围区,阳性细胞数量相对较少,其变化规律与模型对照组相似,同一时间点相比较,藻蓝蛋白组周围区COX-2阳性细胞数均显著低于模型对照组。(2)假手术组和模型对照组非缺血侧脑组织可见到少量COX-2 mRNA的表达。模型对照组COX-2 mRNA阳性细胞主要位于缺血周围区,而缺血中心区阳性细胞明显减少。缺血再灌注6 h后COX-2 mRNA阳性细胞数逐渐增加,至再灌注12 h达高峰,持续24 h^3 d,然后开始下降,至14 d时仍有表达,略高于假手术组;藻蓝蛋白组COX-2 mRNA阳性细胞数量相对较少,其变化规律与模型对照组相似,与模型对照组同一时间点相比,差别有显著性意义(P<0.05)。结论脑缺血再灌注后,缺血周围区的神经元内COX-2及COX-2 mRNA均高表达,其在局灶性脑缺血再灌注损伤中起重要作用。藻蓝蛋白可能通过选择性抑制COX-2及COX-2 mRNA的表达来抵抗脑缺血损伤,对脑缺血再灌注损伤具有保护作用。
Objective To study the effects of phycocyanin on the expression of COX - 2 and COX - 2 mRNA after cerebral ischemia/reperfusion in rats. Methods A rat middle cerebral artery occlusion/reperfusion （MCAO） model was produced by using the intraluminal filament occlusion. The rats were divided into three groups ： sham operation group, model control group and phycocyanin group. After MCAO/reperfusion, the neurobehavioral testing of all rats was made. The infarction area was evaluated with the method of 2, 3, 7 - triphenyhetrazolium chloride （TTC） staining. The expression of COX - 2 was determined by immunohistochemical analyses, and the expression of COX - 2 mRNA was determined by in site hybridization. Results （ 1 ） In the sham operation group and the model control group, only a few COX - 2 positive cells were seen in the normal cerebral tissue. In the model control group, COX- 2 positive cells were mainly in the penumbral area （the cerebral cortex of MCAO）, but only a few can be seen in the ischcmic core （lateral striatum）. COX -2 positive cells increaced at 6 h after ischemia/reperfusion, reached a maximum at 24 h and subsided at 48 h, but still in higher level until 14 th day than the sham operation group. In the phycocyanin group, COX -2 positive cells were also mainly in the penumbral area, but the number of the cells were significantly lower than that of the model control group. The time - phase pattern of COX - 2 is similar to that of the model control group. （2） In the sham operation group and the model control group, only a few COX -2 mRNA positive cells were seen in the normal cerebral tissue. In the model control group, COX- 2 mRNA positive cells were mainly in the penumbral area, but only a few can be seen in the ischemic core. COX -2 mRNA positive cells increaced at 6 h after ischemia/reperfusion, reached a maximum at 12 h, lasted 24 h - 3 d, then subsided, but still in higher level until 14 th day than the sham operation group. In the phycocyanin group, the number of the COX - 2
出处
《中国全科医学》
CAS
CSCD
2006年第2期120-123,共4页
Chinese General Practice
基金
山东省自然科学基金资助项目(Y2001C04)
