局灶脑缺血时碱性成纤维生长因子和内皮生长因子的表达及其关系

Expressions of bFGF and VEGF in focal cerebral ischemic rats and their relationship

目的:就血管内皮生长因子(vascularendothelialgrowthfactor,VEGF),碱性成纤维细胞生长因子(basicfibroblastgrowthfactor,bFGF)和VEGF-mRNA在局灶脑缺血不同时间和不同部位的表达和变化及他们之间的关系进行探讨。方法:SD大鼠48只。根据缺血时间和再灌时间分为9组,采用线栓并环扎的方法建立局灶脑缺血再灌模型,采用单片脑组织四氮唑(TTC)染色定位的方法确定中心区和边缘区。LSAB法免疫组化染色观察缺血中心区和边缘区VEGF,bFGF免疫阳性表达。RT-PCR法检测VEGF-mRNA动态变化。结果:在缺血3～6h,缺血中心区与边缘区VEGF,bFGF免疫阳性反应同时达高峰。单纯缺血组6h中心区和边缘区VEGF-mRNA转录水平达高峰,分别为0.86±0.07,1.00±0.11,24h基本降至正常水平。而假手术组和24h组中心区分别为0.20±0.04,0.22±0.04。缺血再灌组6h中心区和边缘区也在6h达高峰,分别为0.60±0.02,0.62±0.07,24h基本降至正常水平。假手术组和24h组中心区分别为0.20±0.037,0.31±0.04。结论:VEGF,bFGF早期的高表达在缺血损伤中起重要的作用,可能与神经细胞和内皮细胞的自身保护作用有关,VEGF,bFGF有相互促进表达的作用。

AIM:To study the expressions and changes of vascular endothelial growth factor(VEGF),basic fibroblast growth factor(bFGF),and VEGF and mR-NA in different ischemic cerebral areas and at different time and to study their relationships.METHODS:Fifty-four SD rats were divided into9groups according to is-chemic and reperfusion time.The isc hemic models were established with t he methods of thread occlusion and cerc lage.Triphenyl tetrazolium chloride method(TTCM)was used to definite the center and ma rginal zone.LSAB immunohistochemica staining was used to observe the positive expressio n of VEGF and bFGF in the center and margin al zone after ischemia.RESULTS:At 3-6hours of ischemia,the positiv e reactions of VEGF and bFGF simultaneously reached the peak in ischemic centers and marginal zones,and in the simple ischemic gro up the transcriptional levels of VEGF-mRNA in ischemic center and marginal zone were increased to the peak at 6hours after ischemia,which were(0.86±0.07)and(1.00±0.11),and reduced to the normal level at 24h ours.The transcriptional levels of VEGF-mRNA were 0.20±0.04f or the control group and 0.22±0.04for the 24h group in the ischemic centers,and those of the 6h ischemic reperfusion group were increased to the peak,which were 0.60±0.02and0.62±0.07in the ischemic center and marginal zone respectively,and reached to the normal level at 24hour s.