大鼠缺血心肌中碱性成纤维细胞生长因子的动态变化及其对血管新生的影响

Changes of the Activity of Basic Fibroblast Growth Factor and Its Effect on Angiogenesis in Ischemic Myocardium of Rats

为观察心肌梗死后不同时期心肌中碱性成纤维细胞生长因子表达的变化规律 ,评价碱性成纤维细胞生长因子对血管新生的影响 ,采用免疫组织化学方法分别检测大鼠心肌梗死后 2 4h及 1、2、3和 4周时缺血心肌中碱性成纤维细胞生长因子蛋白质的表达情况 ;另将 6只心肌梗死大鼠给予碱性成纤维细胞生长因子中和抗体腹腔注射 ,2周后检测缺血心肌中毛细血管及小动脉密度的变化。结果发现 ,心肌梗死 2 4h后 ,缺血心肌中碱性成纤维细胞生长因子蛋白质的表达明显增加 ,1～ 2周达高峰 ,3周后开始下降 ,4周时下降更明显 ,但仍高于正常大鼠 ;心肌梗死 2周时缺血心肌中毛细血管密度和小动脉密度均显著增加 ,给予碱性成纤维细胞生长因子中和抗体后小动脉密度显著减少 ,毛细血管密度没有变化。结果提示 ,大鼠急性心肌梗死后缺血心肌中碱性成纤维细胞生长因子持续升高达 1月以上 。

Aim To investigate the changes of expression of basic fibroblast growth factor (bFGF) and to evaluate the effect of bFGF on angiogenesis in ischemic myocardium after acute myocardial infarction. Methods 30 male infarcted rats were divided into 24h group, 1w group, 2w group, 3w group and 4w group, expression of bFGF protein in ischemic myocardium was detected with immunohistochemical staining. Another 6 infarcted rats were treated with bFGF neutralizing antibody for 2 weeks. Capillary density and arteriolar density were detected in ischemic myocardium. Results Expression of bFGF protein in ischemic myocardium increased at 24 hours after acute myocardial infarction, and peaked at 1～2 weeks after acute myocardial infarction, while gradually decreased at 3 weeks after acute myocardial infarction. The expression of bFGF at 4 weeks after acute myocardial infarction still was above normal level. Capillary density and arteriolar density were significantly augmented at 2 weeks after acute myocardial infarction. Arteriolar density in ischemic myocardium was greatly decreased, but capillary density was in absence of change, after action of bFGF was blocked. Conclusions Expression of bFGF protein in ischemic myocardium after acute myocardial infarction was increased continuously for 1 months or more. bFGF mediates proliferation of arterioles in ischemic myocardium.