Effects Of Recombinant Human Erythropoietin On Postresuscitation Cardiac Function In Rabbits

Objective Postresuscitation myocardial dysfunction contributes to the high fatality rate following successful resuscitation. The purpose of this animal research was to observe the effects of recombinant human erythropoietin (rhEPO) on postresuscitation cardiac function in the rabbits and further explore the underlying mechanism by which rhEPO exert protective effects on ischemia reperfusion injury myocardium.Methods After setting up rabbit model of cardiopulmonary resuscitation,18 rabbits were randomly divided into three groups,group A:operation-control group, only anesthesia, surgery, endotracheal intubation, but was not induced ventricular fibrillation; group B:epinephrine group, administration of the standard dose of epinephrine (30μg/kg) during CPR; group C:epinephrine and rhEPO group, on the base of group B,administration of rhEPO(5000IU/kg)after restoration of spontaneous circulation (ROSC) 5 minutes. The left ventricular end-diastolic pressure (LVEDP) and peak first derivative of left ventricular pressure (±dp/dt) were observed. The ischemia reperfusion-induce apoptosis and the apoptosis inducing factor(AIF) were detected by TUNEL and the immunochemical method respectively,and compared the apoptosis index(AI) and the percent of the AIF each groups.The ultrastructure of myocytes was observed by electron telescope.Results①The LVEDP and peak±dp/dt of group A before and after resuscitation in the recovery of all observation time points were no significant differences(P>0.05).②Compared with group A, the LVEDP of the remaining groups gradully increased in ROSC immediately(P<0.05 or P<0.01), but decreased after ROSC60th,whereas the decreasing in group C was lower than in group B at the time of ROSC 120th(P<0.01).③Compared with group A,the peak±dp/dt of the remaining two groups gradully decreased in ROSC immediately(P<0.05 or P<0.01), whereas the peak±dp/dt in group C began to increase in ROSC 60th until ROSC 120th(P<0.01).④The AIs in three groups were (6.4±2.3)%,(31.2±2.4)%and(12.0±3.2)%,respectively.And compared with each of groups were all having the significant differences(P<0.01).⑤The percentages in three groups were (7.4±2.7)%,(30.2±1.8)%and(18.5±4.7)%,respectively.And compared with each of groups were all having the significant differences(P<0.05or P<0.01).⑥The ultrastructure in group B was protected better than those of group C.Conclusions rhEPO administered after resuscitation improved postresuscita-tion hemodynamics. It inhibited the expressing of apoptosis inducing factor,the cardiocyte apoptosis and alleviated cardiac ultrastructure damage at the early stage of cardiopulmonary resuscitation after CPR from cardiac arrest,and imporoved postresuscitation myocardial dysfunction.