Erythropoietin promotes hepatic regeneration after extended liver resection in rats

Abstract Background and Aim: It has been proven in various animal studies that recombinant human erythropoietin (rHuEPO) protects renal, cardiac and neuronal, as well as hepatic, tissue from ischemia, and promotes regeneration of adult central nervous system neurons. To date, no data are available as to whether rHuEPO has the ability to stimulate liver regeneration after liver resection. Methods: Rats undergoing 70% or 90% hepatectomy received an intraportalvenous administration (i.p.) of rHuEPO prior to resection or a subcutaneous injection (s.c.) for 3 days postoperatively, control animals were treated with surgery and saline injection only. Regeneration capacity of remnant livers was studied over 7 days by histology and immunohistochemistry (Ki‐67, proliferating cell nuclear antigen [PCNA]). Polymerase chain reaction was carried out to measure transforming growth factor β (TGF‐β), hypoxia induced factor (HIF), signal transducing activator 3 and vascular endothelial growth factor. Results: Ten‐day survival in rats undergoing 90% hepatectomy significantly increased in i.p.‐pretreated animals. After 70% hepatectomy the mitotic index was significantly increased in both rHuEPO‐treated groups. These data were confirmed by PCNA and Ki‐67 expression, which was significantly increased in the treated groups 24 h and 2 days after liver resection. TGF‐β and HIF mRNA both were upregulated in control animals 3 h after surgery. Conclusion: rHuEPO effectively increased liver regeneration in rats after 70% liver resection and enhanced survival after 90% hepatectomy. Thus, rHuEPO may increase the regenerative capacity after major hepatectomy.