Objective To observe the impact of hypoxia/reoxygenation on myocardial cytoskeletal proteins (α-actinin protein,tubulin protein,desmin protein) and to investigate EPO lessening the damage of myocardial cytoskeleton proteins in rats proved by culturing hypoxia/reoxygenation injured myocardial cells in presence of EPO.Methods The rat model of asphyxia-induced cardiac arrest was performed by turning-off the ventilator and clamping the endotracheal tube.After asphyxia for 8 minutes,CPR was carried out.A total of 24 rats were divided into normal group,ischemia/resuscitation (I/R) group and the EPO group (n =8).The model of myocardial dysfunction was determined 2 hours after restoration of spontaneous circulation (ROSC).The rats of EPO group were given EPO 5000 U/kg after ROSC.The rat heart specimens were collected.Actinin,Tubulin and Desmin protein were observed by SABC immunohistochemistry.The cultured cardiomyocytes were taken from neonatal rats and were divided into three groups:the normal group,the hypoxia/reoxygenation (H/R) group (hypoxia 10 h/reoxygenate 4h),the EPO group (hypoxia 10 h/reoxygenate 4 h,plus 10 U/mL EPO).The changes of tubulin and actinin in cultured cardiomyocytes were observe by Immunofluorescence.Results From immunohistochemistry,there were no significant difference in the optical density of actinin,tubulin and desmin among the normal,I/Rand EPO groups.After H/R injury,the structures of the actinin,tubulin protein were destroyed,the network structure of both protein were unclear in cultured myocardial cells.The grades of fluorescence intensity of actinin and tubulin in H/R group were significant lower than those in normal group,but there was no significant difference between H/R group and EPO group.Conclusions The damage of cytoskeleton during ischemia/reperfusion may be time-dependent.EPO has no beneficial effect on the cytoskeleton after I/R injury.