OBJECTIVETo investigate the effect of Qidan Liquid (QL) on myocardial angiogenesis in rats after acute myocardial infarction (AMI) and explore its possible molecular mechanism.

METHODSAMI model was established by ligating the left anterior descending (LAD) coronary artery in Wistar rats, and intervened with QL in high, medium and low doses (QLh, QLm and QL1 group), and isosorbide dinitrate (ID group) respectively. Meanwhile, the model group, the sham group and the normal group were also set up. On the 7th (d7) and 14th day (d14) after modeling, mRNA and protein expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were detected with RT-PCR and immunohistochemistry, factor VIII expression in endothelial cells was examined, and microvascular density (MVD) in ischemic myocardium was calculated.

RESULTSMVD in the model rats increased significantly, higher than that in the normal and the sham group (P < 0.01), on d7 and d14, it was lower in the model group than that in the high and medium dose of QL groups and the ID group (P < 0.05). On d7, VEGF protein expression in the model group was higher than that in the normal group (P< 0.05), equivalent to that in the other groups, on d14, it was lower than that in the high and medium dose of QL groups and the ID group (P < 0.05 or P < 0.01). On d7 and d14, the protein expression of bFGF in the model rats increased significantly, higher than that in the normal and the sham group (P < 0.01), it decreased along the time progress between the two time points (P < 0.05), and lower than that in the high dose of QL group and ID group (P < 0.01). The mRNA expressions of VEGF and bFGF were higher in the model group than those in the normal and sham group, but lower than those in all the treated groups on d7 and d14. Comparison of the strips on d7 and d14 among various groups showed that the bFGF mRNA expression in the model group showed a descending trend as the time goes on, but in all the treated groups it was unchanged, while the change of VEGF mRNA expression didn't show any definite tendency.

CONCLUSIONQL could up-regulate the protein and gene expressions of VEGF and bFGF persistently and increase MVD in ischemic myocardium to promote the development of collateral circulation in AMI rats.