[Effect of mesenchymal stem cells transplantation on heart function after acute myocardial infarction].

OBJECTIVE: To investigate whether mesenchymal stem cells (MSCs) transplantation after acute myocardial infarction (AMI) can improve heart function and decrease infarct size in rabbits and their correlation. METHODS: Twenty-four rabbits were randomly divided into AMI group and MSCs group, each n=12. Exogenous MSCs labeled with bromodeoxyuridine (BrdU) were injected into the border and central area of the ischemic myocardium. Heart function was assessed with echocardiography before transplantation of MSCs and in 6th week after the transplantation. Surviving MSCs in infarcted myocardium were identified by immunohistochemistry. Infarct size was measured histologically. Correlation of heart function and infarct size were analysed. RESULTS: Immunohistochemical stain revealed that BrdU-positive cells were seen in the infarcted myocardium in MSCs group but not in AMI group. Transplantation of MSCs was associated with a significant diminution of left ventricular end-diastolic dimension (LVEDD), and left ventricular end-systolic dimension (LVESD, both P<0.05), and left ventricular ejection fraction (LVEF) and fractional shortening (DeltaFS%)increased (both P<0.05) as compared with AMI group. Infarct size as measured histologically was significant smaller in MSCs group than AMI group (P<0.05). There were negative correlations between LVEF and infarct size in two groups (both P<0.01). CONCLUSION: Exogenous MSCs transplantation can improve heart function by decreasing infarct size and therefore it might be beneficial in the treatment of AMI.