Abstract: Objective To investigate the feasibility of acute myocardial infarction(AMI)treated with transplantation of bone marrow mesenchymal stem cells(MSCs).Methods Fifty female Wistar rats were randomly divided into the transplant group and control group with 25 animals in each group.The AMI animal model was made by liquid nitrogen freezing.Rat MSCs cultured and induced repeatedly was prepared for transplantation and injected into the infarcted parts of the transplant group.The same volume of DMEM solution was injected into the infarcted parts of the control group.Echocardiography was applied one day preoperation,and one week and four weeks postoperation to evaluate cardiac function.The animals of the transplanted group were executed in the fourth week after operation and the tissues of transplant part were examined by BrdU immunofluorescent stain.Results Some transplant cells expressed the cardiac-specific proteins,α-actin and troponin T.The cardiac function of the transplant group had better than that of the control group(P>0.05)in the fourth week postoperation.The BrdU-labeled cells were found in the histological sections of the transplant parts.Conclusion Rat MSCs cultured generation by generation and repeatedly induced by 5-aza in vitro can differentiate into cardiomyocyte-like cells,which if transplanted into the rat infarcted cardiac muscles will survive and help to improve the host's cardiac function.

Key words: bone marrow, mesenchymal stem cells, allogeneic transplantation, acute myocardial infarction, tissue Doppler echocardiography