RESUMO
Background Stromal cell-derived factor-1_?(SDF-1_?)has been demonstrated to be essential for stern cell mobilization/homing.Recent evidence indicates that SDF-1_? has been expressed in injured carotid arter- ies.Besides,high SDF-1_? plasma levels are clinically associated with stable coronary artery disease.Objective To investigate whether SDF 1 involves in mobilization of endothelial progenitor cells(EPC)and reendothelialization after vascular injury.Methods SDF-1_? was detected by RT-PCR and Western blot in carotid arteries of mice at different time points after wire-induced injury.SDF-1_? determination in peripheral blood samples and BM was per- formed by SDF-1_? enzyme-linked immunosorbent assay(ELISA)kit.EPC in peripheral blood collected at different time points after vascular injury were quantified by flow cytornetry.In subgroup,blocking SDF-1 rnonoclonal anti- body was injected,peripheral blood EPC were quantified after vascular injury and reendothelialization of injured ar- teries was determined 14 days later.Results Expression of SDF-1_? was evident at day 1,and peaked at day 3 after arterial injury.A rise in plasmatic concentration of SDF-1_? and a significant reduction of SDF-1_? in bone marrow concentration was noticed at all time points following injury.The amount of circulating EPC was increased shortly after induction of vascular injury and persisted up to 7 days(P