The effect of erythropoietin on myocardial cytoskeletal proteins after hypoxia/reoxygenation injury / 中华急诊医学杂志

ABSTRACT

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 groupsthe 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.