Effect Of Stem Cells Transplantation Incorporated With Transmyocardial Revascularization In Repairing Infarcted Myocardium Of Rabbit

Objective:To investigate the feasibility and efficiency of MSCs (mesenchymal stem cells) transplantation incorporated with machine drilling TMR (transmyocardial revascularization) in repairing infracted myocardium of rabbit.Methods: MSCs from rabbit were abstracted, isolated, cultured and inducedby 5-azacytidine. The 22 rabbits were randomly and evenly divided into 2 groups: the experiment group (MI+Cell) and the control group (MI+ TMR + Cell). Half an hour after ligating of left anterior descending coronary artery(LAD), the control group (MI+ TMR +Cell) were treated with machine drilling. 10 minutes later, the MSCs transfected with blue fluorescent protein gene were injected into five different sites bordering the channel of mechanical TMR subsequently. The control group were only treated with MSCs. Cardiac function was tested by Doppler echocardiography 24 hours and 4 weeks after the modeling of myocardial infarction, to analysis the left ventricular ejection fraction(EF), fraction shorting(FS) and left ventricular end diastolic diameter (LVEDD). The rabbits were sacrificed 4 weeks later and the myocardium was harvested. Fluorescence tracing was used to determine the survival of the transplanted MSCs in the ischemic myocardium. Immunohistochemical staining was performed to assess the differentiation of the transplanted MSCs and myocardial capillary density of the infarcted areas.Results: 24 hours after, there is no difference about the cardiac functions of ejection fraction(EF), fraction shortening(FS), left ventricular end diastolic diameter (LVEDD) between the two groups (p>0．05) , but four weeks after, the EF, FS, LVEDD in experimental group were better than those in the control group (p<0．01) ; The implanted MSCs were found in the ischemic tissue by fluorescence microscope, the grafts in the experiment group distribute more wider than those in the control group; Donor cells maybe derived from MSCs demonstrate myogenic differentiation with the expression of troponin T. The density of capillaries in the experiment group was significant increased than that in the control group (p<0．05) .Conclusion: Bone mesenchymal stem cells transplantation incorporated with TMR enhance revascularization and viability of transplanted cells in infarction area, and improve eventually ventricle function.