Erythropoietin improves cardiovascular function in adult rats after acute hemorrhage

Erythropoietin (EPO) has been linked to cardioprotective effects. However, its effects during the aging process are little known. We investigated the effect of EPO administration on hemodynamic parameters, cardiac function, oxidative damage, and EPO receptor (EPOR) expression pattern in hypovolemic state. EPO was administered (1000 IU/kg/3 days) and then acute hemorrhage (20% blood loss) was induced in young and adult rats. There was no difference in plasmatic EPO in either age group. Hemodynamic basal condition was similar, without alterations in renal function and hematocrit, in both age groups. After bleeding, both EPO treated age groups had increased blood pressure at the end of the experimental protocol, being greater in adult animals. EPO attenuated the tachycardic effect. Ejection fraction and fractional shortening were higher in adult EPO treated rats subjected to hemorrhage. In the left ventricle, young and adult EPO treated rats subjected to bleeding showed an increased EPOR expression. A different EPOR expression pattern was observed in the adult right atrial tissue, compared to young animals. EPO treatment decreased oxidative damage to lipids in both age groups. EPO treatment prior to acute hemorrhage improves cardiovascular function during the aging process which is mediated by different EPOR pattern expression in heart tissue.