奥美沙坦酯对急性心肌梗死大鼠心肌血管新生的促进作用

目的探讨奥美沙坦酯对急性心肌梗死（AMI）大鼠心肌血管新生的影响。方法结扎SD大鼠左冠状动脉前降支制作AMI模型。将术后24h存活的24只大鼠随机分为3组，每组8只：单纯心肌梗死组（AMI组）、奥美沙坦酯1mg·kg^-1·d^-1组（OML组）和奥美沙坦酯3mg·kg^-1·d^-1组（OMH组）。另设假手术组（Sham组）8只作为对照。术后24h始灌胃给药共2周。ELISA法测定血清血管内皮生长因子（VEGF）含量，以Ⅷ因子相关抗原抗体做内皮细胞免疫组化染色测定心肌微血管密度（MVD）。结果与Sham组比较，AMI组、OML组和OMH组血清VEGF含量均明显升高（P〈0．05），与AMI组比较，OML组和OMH组血清VEGF含量无明显变化（P〉0．05）；与Sham组比较，AMI组心肌微血管密度明显增加（P〈0，05），与AMI组相比，OML组和OMH组的心肌微血管密度明显增加（P〈0．05）。结论奥美沙坦酯能促进AMI大鼠心肌血管新生，此效应与VEGF途径无明显相关。

Enhancement of olmesartan medoxomil on myocardial neovascularization in rats with acute myocardial infarction

Objective To investigate the effect of olmesartan medoxomil on myocardial neovascularization in rats with acute myocardial infarction. Methods Myocardial infarction （MI） was induced by ligation of the left coronary artery in SD rats. Starting 24 h after ligation,sham-operated rats received vehicle treatment （the sham group, n=8 ）and surviving rats with MI were randomized to 2 weeks treatment by gavage with vehicle （the AMI group,n=8）or olmesartan medoxomil（the OMH group：3 mg·kg^-1·d^-1,n=8 or the OML group： 1 mg·kg^-1·d^-1,n=8）. Serum VEGF levels were determined by ELISA 2 weeks after MI. Left ventricles were cut along cross-sections immediately after the death of rats and then made into paraffin sections. Numbers of MVD were calculated by immunohistoehemical method using antibody of factor Ⅷ related antigen. Results 2 weeks after MI, Serum VEGF levels were significantly increased in the AMI,the OML and the OMH groups than in the Sham group （P〈0.05）, there was no difference in serum VEGF levels between the olmesartan-treated group and the AMI group（P〉0.05 ）; 2 weeks after MI,compared with the Sham group,the AMI group MVD of myocardium was significantly higher （P〈 0.05）.compared with the AMI group,the OML and the OMH groups MVD of myocardium increased significantly （P〈 0.05）. Conclusion Olmesartan medoxomil can enhance myocardial neovascularization independently on VEGF.