Objective: To investigate the protective effect and mechanism of Qishen Yiqi drop pills on myocardial injury in rats with myocardial ischemia based on angiogenesis theory. Method: The 160 Sprague Dawley (SD) rats were divided into sham operation group

model group

high dose Qishen Yiqi drop pills group

and low dose Qishen Yiqi drop pills group. Myocardial ischemia models were established by ligating left anterior descending coronary artery in rats. Hematoxylin-eosin (HE) staining was used to detect cardiac pathological changes

platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31)

and α-smooth muscle actin (α-SMA) on days 3

7

14 and 28

immunohistochemical staining was used to detect the blood vessel density in ischemic border zone. Real-time PCR method was used to detect the expression levels of vascular endothelial growth factor (VEGF)

vascular endothelial growth factor receptor 2 (KDR)

basic fibroblast growth factor (bFGF)

angiopoietin (Ang)-1

Ang-2 and platelet derived growth factor-B (PDGF-B) and platelet derived growth factor receptor-beta (PDGFR-β) mRNA. Result: After 3 days of infarction

the infarction area was obviously seen in heart

on days 7~28

with left ventricular dilation

the infarct zone wall was thinning; on days 3~28

new blood capillaries were seen in ischemic border zone; CD31 positive and α-SMA positive blood vessel densities were increased than those in sham operation group. As compared with the model group

high and low dose Qishen Yiqi drop pills could decrease the myocardial infarct size and promote the blood vessels in the border zone at different time points

and could inhibit ventricular dilatation at days 7~28 (P<0.05). PCR results showed that in the early stage of miocardial infarction

angiogenesis and stability related factors were increased; in the late stage of miocardial infarction

vascular maturation related factors were increased (P<0.05). On day 3 of Qishen Yiqi drop pills treatment

the expression levels of VEGF and Ang-1 mRNA were increased

but bFGF mRNA expression level was reduced (P<0.05)

on day 7

the expression levels of VEGF and bFGF mRNA were increased (P<0.05)

on day 14

the expression levels of VEGF

Ang-1

bFGF and PDGFR-β mRNA were increased (P<0.05)

on day 28

the expression level of bFGF mRNA was increased

but VEGF

KDR

Ang-1

and Ang-2 mRNA expression levels were reduce (P<0.05). Conclusion: Qishen Yiqi drop pills can protect the myocardium in myocardial infarction model of rats

and the mechanism may be related to the regulation of angiogenesis and maturation-related factors in ischemic border zone.