碱性成纤维细胞生长因子及其受体在心肌梗死心脏组织中的分布

Distribution of basic fibroblast growth factor and its receptor in minipig heart after myocardial infarction

目的研究碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)及其受体(fibroblast growth factor receptor-1,FGFR-1)在正常及心肌梗死后心脏组织中的分布和变化情况,探讨bFGF在心肌梗死中对心脏的保护作用。方法普通级正常成年西双版纳微型猪11只,实验组(n=6)通过结扎成年微型猪的左冠状动脉前降支建立心肌梗死模型,对照组(n=5)模拟开胸手术过程,但不结扎冠状动脉,4周后取出心脏,采用免疫组化法和图像分析方法检测2组实验动物心脏组织中bFGF和FGFR-1的水平。结果①正常对照组的心房心肌细胞内bFGF和FGFR-1的蛋白表达水平高于心室(P<0.05)。②心肌梗死后,实验组左右室心肌组织的bFGF水平明显高于对照组(P<0.05),而以受累左室的增加最为明显。同时,受累左心室中的FGFR-1较对照组也升高(P<0.01),且以梗死边缘区最为显著(P<0.01)。③梗死区周围组织中的血管内皮细胞、平滑肌细胞内bFGF和FGFR-1表达较对照组增多(P<0.05)。结论心肌梗死后受累部位心肌bFGF明显增多,同时FGFR-1显著上调,推测bFGF在心肌梗死后的心脏血管新生、侧支循环建立、组织修复、心脏重构及改善心肌梗死预后方面可能起重要作用。

Objective To investigate the distribution and changes of basic fibroblast growth factor （bFGF） and fibroblast growth factor receptor-1 （FGFR-1） in normal heart or heart after myocardial infarction （MI）,and to explore beneficial effects of bFGF on heart after MI. Methods Eleven adult minipigs were randomly divided into 2 groups,control （n=5） and MI group （n=6）. MI was induced by ligating the left anterior descending coronary artery. Sham-operation was carried out on the animals of control. bFGF-like-immunoreactivity （bFGF-ir） and FGFR-1-like-immunoreactivity （FGFR-1-ir） in heart tissues were detected by immuno-histochemistry and image analysts in 4 weeks after surgery. Results In controls,bFGF-ir and FGFR-1-ir in the atrium showed a considerable high level compared with 2 ventricles （P0.05）. In the minipigs after MI,the levels of bFGF-ir and FGFR-1-ir in the left ventricle was significantly increased （P0.05）,especially in the area near to MI （P0.01）. The levels of bFGF-ir and FGFR-1-ir in the vascular endothelial cells （VEC） and vascular smooth muscle cells （VSMC） adjacent to the infarcted region also significantly increased compared with those in the controls （P0.05）. Conclusion bFGF and FGFR-1 mostly localize in the atrium in normal heart,and they significantly increase in the infarcted region after MI. The results suggest that bFGF might play an important pathophysiological role in neovascularization,collateral growth,tissue recovery and cardiac remodeling after MI.