Abstract:Objective Rabbit endothelial progenitor cells were harvested from culturing bone marrow with EGM-2MV (n=10), and efficacy of the cells expansion was observed. Methods Three millimeter bone marrow of each rabbit was cultured with EGM-2MV medium in flasks coated with fibronectin. Morphology was observed with phase contrast microscopy, and a growth curve was constructed to evaluate the efficacy of expansion. Twelve days later, the attached cells were identified with immunocytochemical staining for CD133, CD34, vascular endothelial growth factor receptor 2(VEGFR-2). The function of cells was tested by evaluating the ability of incorporation of Dil-ac-LDL and combining FITC-UEA-1 lectin. Meanwhile the attached cells were selected with CD133 immunomagnetic beads. The percentage of CD133, CD34, and VEGFR-2, CD34/ VEGFR-2 and CD133/ CD34/ VEGFR-2 antigen-positive cells were calculated and compared using flow cytometry before and after immunomagnetic beads selection. Results The cluster-like or colony-like growth cells were found 48 h after bone marrow cultured. The cells were spindle, triangle or polygon shaped. The cells growth curve showed \"S\" type. About (1.51±0.29) ×106 attached cells were harvested from each sample twelve days later. The cells took up Dil-ac-LDL and combined with FITC-UEA-1 lectin. Immunocytochemistry showed that CD34, CD133, and VEGFR-2 were positive. The percentage of CD34+/ VEGFR-2+ and CD133+/CD34+/ VEGFR-2+ cells after immunomagnetic beads selection were 3.38 and 6.14 times higher than those of unselected cells, respectively. Conclusion Endothelial progenitor cells can be harvested directly from rabbit bone marrow in a simple and effective method.