Abstract: Objective To study the promoting effect of Shenmai injection on myocardial angiogenesis in myocardial infarction(MI) rats. Methods Forty-one MI model rats were divided into model group, low and high-dose groups, with 10 rats each, and 11 rats in the positive group. Low and high-dose groups were treated with 1, 2 mol/kg of Shenmai injection injected intraperitoneally, positive group was treated with 2 mg/kg enalapril. HE staining was used to observe the pathological changes of myocardial tissue in each group. Immunohistochemical staining was used to observe the capillary density in the infarct area. Western blot was used to detect the relative expression of PI3K, AKT, p-AKT and VEGF protein. Results The pathological changes of the low and high-dose groups and the positive group were reduced. Compared with the sham operation group, the capillary density and arteriole density, the expression of PI3K and VEGF protein, and p-AKT/AKT in the model group were increased (P＜0.05). Compared with the model group, the capillary density and arteriole density, the expression of PI3K and VEGF protein, and p-AKT/AKT in the low and high-dose groups and the positive group were increased (P＜0.05). Conclusions Shenmai injection may promote myocardial angiogenesis in MI rats in a dose-dependent manner. It is speculated that the mechanism of this drug is related to the activation of PI3K/AKT signaling pathway.

Key words: myocardial infarction, Shenmai injection, myocardial angiogenesis, phosphatidylinositol 3-kinase, protein kinase B