Objective   To investigate the possible mechanisms of transplanting adipose tissue-derived mesenchymal stem cells (ADMSCs) on the angiogenesis in acute myocardial infarction (AMI) rabbits. Metheds

A total of 30 health rabbits were randomly divided into 3 groups: shameoperation group

acute myocardial infarction (AMI) group

and AMI+ADMSCs transplantation group. AMI model was induced by ligating the anterior interventricular branch. 4’

6-diamidio-2-phenylindole (DAPI)-labeled ADMSCs at passage 3 which were primarily cultured from rabbit greater omentum fat tissues and identified with flow cytometry for expressions of CD34

CD45

CD44 and CD71 were injected into the center and edge of infracted area of AMI+ADMSCs group with 5 sites (0.2 ml

1×10

6

/L for each site)

and the same dose of phosphate buffered solution (PBS) was given to the AMI group. Echocardiography was performed to evaluate the cardiac function before operation and 4 weeks after operation. Then the animals were sacrificed and their hearts were resected. The regeneration of microvessel was examined with immunohistochemical technique for microvessel density (MVD)

and the expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in ischemic region were detected with transcription-polymerase chain reaction (RT-PCR).  Results  The labeled cells were visible in the recipient heart

and some of them were differentiated into cardiac-like cells. Echocardiography showed heart function in ADMSCs group was better than that of AMI group in 4 weeks after surgery

with obviously improved left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (FS)

and significantly shorter left ventricular end-diastolic inner diameter (LVEDd) and left ventricular end-systolic inner diameter (LVEDs) (P0.05). AMI+ADMSCs transplantation group had an obviously higher MVD in the infarction regions than in AMI group (20.00±2.65 vs 7.75±2.12

P0.05). The expressions of bFGF and VEGF in the myocardial tissue of ADMSCs group were significantly higher than those in AMI group (0.590±0.028 vs 0.569±0.021

0.913±0.030 vs 0.886±0.049

P0.05).  Conclusion  Transplantation of ADMSCs promotes the revasculariza

tion in infarcted regions

and improves the heart function by enhancing VEGF and bFGF synthesis.