OBJECTIVETo evaluate the possibility that using intracoronary delivery of autologus bone marrow-derived mesenchymal stem cells (MSCs) to improve the cardiac function after acute myocardial infarction (AMI) in miniature pig.

METHODSMSCs were cultured in Dulbecco's modified Eagle's medium-F12 (DMEM/F12) medium. AMI model was made by blocking the blood stream of the first diagonal branch in miniature pig, and released the branch after 90 minutes. After 10-14 days, (4-6) x 10(7) culture-expanded autologus 4', 6-diamidino-2-phenylindole (DAPI)-labelled MSCs were transplanted into each host heart's AMI area through intracoronary way. Ultrasonic cardiography (UCG) was performed to observe the left ventricular function at 3 months after transplantation. The cellular transplanted hearts were harvested and investigated by immunohistochemical analysis.

RESULTSLeft ventricular function of the MSCs group was improved significantly 3 months later compared with the control group [(54.65 +/- 3.39) vs (43.98 +/- 4.21)%, (P < 0.01)]. Exogenous MSCs survived and site-differentiated into cardiomyocytes in infracted hearts.

CONCLUSIONMSCs can play a benificial role to repair damaged heart. Heart function can be improved after MSCs transplantation in porcine myocardial infarction model.