美托洛尔对大鼠缺血心肌血管新生及血管内皮生长因子表达的影响

The Effects of Metoprolol on Angiogenesis and Expresssion of VEGF in Ischemic Myocardium of Rats

目的:观察美托洛尔对大鼠缺血心肌血管新生和缺血心肌血管内皮生长因子(VEGF)表达的影响。方法:运用大鼠心肌缺血模型,随机分为给药组和模型组,并记录心率。用免疫组织化学方法检测缺血心肌中内皮细胞数、毛细血管密度、VEGF蛋白质的表达,用RT-PCR方法检测VEGF mRNA的表达。结果:(1)与模型组比较,给药组大鼠缺血心肌毛细血管密度和内皮细胞数均明显增加(P<0.01),其心率明显降低(P<0.01);(2)与模型组比较,给药组大鼠缺血心肌VEGF蛋白质及mRNA的表达均明显增加(P<0.01)。结论:(1)美托洛尔能促进大鼠缺血心肌的血管新生;(2)美托洛尔减慢心肌缺血大鼠的心率和上调VEGF的表达可能是其促大鼠缺血心肌血管新生的机制之一。

Objective： To observe the effects of metoprolol on angiogenesis and expresssion of vascular endothelial growth factor （VEGF） in ischemic m myocardium infarction were divided randomly into metoprolol group （ group A, treated with metoprolol, n=18） and model group （goup B, rats with ischemic myocardium but did not receive treatment,n = 18）, and their heart rates were recorded. Endothelial cells （EC）, capillary density （CD）, and VEGF protein expression were detected with immunohistochemical method, while RT-PCR method was adopted for the assay of VEGF mRNA. Results： （ 1 ） EC and CD of rats in group A were significantly higher than those of rats in group B （ P 〈 0.01 ） ; and the heart rate of rats in group A was obviously lower than that in group B（P 〈 0. 01 ）. （2） The protein expression and mRNA expression of VEGF were significantly higher in ischemic myocardium of group A than those of group B（P 〈0. 01 ）. Conclusions： Metoprolol may promote angiogenesis in ischemic myocardium of rats. One of the mechanisms might be that Metoprolol can decrease the heart rate and increase the expression of VEGF.