AIM:To investigate the potential of differentiatng into myocytes of the granulocyte colony-stimulating factor(G-CSF)-mobilized CD34 + cells. METHODS: Three hours after intraperitoneal injecction of isoprenaline(ISO) to develop acute ischemic model, rats' bone marrow hematopoietic stem cells were mobilized to the site of myocardial infarction by G-CSF. The techniques of immunohistochemisty and HE stain were used to detect the infiltration of CD34 + cells and the regeneration of myocytes in the infarct zones. RESULTS: 24 hours after administration of ISO , a large amount of infiltrative monocytes and regenerative myocytes which were CD34 positive expression could be found in the infarct zones of the G-CSF treatment group, while majority of the infiltrative inflammatory cells in control group were neutrophils and there was no infiltrative cells and myocytes which were CD34 positive expressio, 2 weeks after administration of ISO, there were a plenty of scar in control group, but not in the G-CSF treatment group. CONCLUSION: G-CSF-mobilized CD34 + cells possess the potential to differentiate into myocytes and it may be used in treating acute myocardial infarction.

AIM: To investigate the effects of granulocyte colony-stimulating factor (G-CSF)-mobilized bone marrow stem cells on treatment of the myocardial infarction in experimental rats. METHODS: Three hours after injected with isoprenaline(ISO) interaperitoneally to develop acute ischemic model, rats' bone marrow stem cells were mobilized by G-CSF and migrated to the site of myocardial infarction. The hearts were harvested from 24 hours to 2 weeks after administration of ISO for histopathological examination. RESULTS: 24 hours after administration of ISO , myocardial infarct zones scattered in the pallium of the control group ,there were a large amoumt of inflammatory cells infiltration around the infarct zones and majority of them were neutrophils. The infarction in the G-CSF treatment group was milder, majority of the infiltrative cells were monocytoid; 48 hours after administration of ISO, infarct zones expanded greatly in control group, while that of the G-CSF treatment group increased just mildly; 2 weeks after administration of ISO, there was no significant scar in the G-CSF treatment group. We also found the regeneration of myocytes in the pallium. CONCLUSION: G-CSF treatment protected the ischemic myocardium and it may be used to treat the acute myocardial infarction.