Abstract:

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) have the potential to differentiate into various cells. BMSCs induced by 5-azacytidine were transplanted into myocardium of rabbits after myocardial infarction. Whether transplanted stem cells could improve cardiac function in short or long time was unclear.
OBJECTIVE: To investigate the effects of BMSCs transplantation on cardiac function in rabbits after acute myocardial infarction (AMI).
METHODS: Rabbit BMSCs were purified and cultured in vitro. BMSCs were induced by 5-azacytidine, and labeled with DAPI at 4 weeks following induction. New Zealand rabbits were randomly divided into three groups. In sham operation group, the chest was opened for 1 hour and then closed. In BMSCs group, autologous BMSCs were infused into the surrounding infarct area at 4 points using a microsyringe at 1 hour following model induction by coronary artery ligation. In AMI group, an equal volume of saline was injected at the same region following model establishment. At 3 days and 4 weeks following transplantation, ultrasonic cardiography was used to determine changes in left ventricular end diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) in rats from each group.
RESULTS AND CONCLUSION: Fluorescence microscopy results demonstrated that DAPI-labeled BMSCs were distributed extensively in the myocardium of BMSCs group at 3 days and 4 weeks, arranged in parallel with the cardiac muscle fibers. At 3 days after transplantation, there were no significant differences in LVEDV, LVESV and LVEF between AMI and BMSCs groups. No significant improvement was found in cardiac function. At 4 weeks after transplantation, LVEDV and LVESV were significantly decreased, and LVEF was significantly increased in BMSCs group compared with AMI group.