Repair Of Infarcted Myocardium By Intramyocardial Transplantation Of Mobilized Autologous Bone Marrow Stem Cells

Objective To investigate the effects of recombinant human Granulocyte colony Stimulating factor(rhG-CSF)-mobilized bone marrow stem cells on treatment of acute myocardial infarction in rats. Methods 90 rats were randomly divided into 2 groups: control group and treatment group. Under sterilization,a rat model was made by opening chest and ligating the left anterior descending (LAD) coronary artery.Three hours after LAD ligation , the rates of treatment group were treated with Filagrastim (rhG-CSF,10μg/kg.d-1) for 5 days and those of control group were received saline. Heart fuction (±dp/dt max )were quantified 24 hours ,48 hours and 2 weeks after LAD ligation then hearts were harvested for histopathological examinatio and infarcted zone were quantified. Immunohistochemisty and HE stain were used to detect infiltration of CD34+ monocytes and the regeneration of myocytes in the infarction zone.After 2 weeks of LAD ligation then shortening fraction (SF) and ejection fraction (EF) were quantified by echocardiography before the above mentioned examinations. Results The value of ±dp/dt max of treatment group were higher than that of contol group(P<0.01).Compared with control group ,treatment group had higher EF(P<0.01)and FS(P<0.01)and smaller infarcted zone(P<0.01)after 2 weeks of LAD ligation. Large number of infiltrative monocytes and some regenerative myocytes with positive expression of CD34+ were found in the infarct zones of the treatment group,while majority of the infiltrative inflammatory cells in control group were neutrophils and there were no infiltrative cells and myocytes with positive expression of CD34+. Conclusions In situ transplantation of autologous bone marrow stem cells mobilized by G-CSF can repair the infarcted myocardium,reduce infarction size and improve cardiac founction.