Original Article Erythropoietin protects against ischaemic acute renal injury

Background. Erythropoietin (EPO) has recently been shown to exert important cytoprotective and anti-apoptotic effects in experimental brain injury and cisplatin-induced nephrotoxicity. The aim of the present study was to determine whether EPO admin-istration is also renoprotective in both in vitro and in vivo models of ischaemic acute renal failure. Methods. Primary cultures of human proximal tubule cells (PTCs) were exposed to either vehicle or EPO (6.25–400 IU/ml) in the presence of hypoxia (1 % O2), normoxia (21 % O2) or hypoxia followed by normoxia for up to 24 h. The end-points evaluated included cell apoptosis (morphology and in situ end labelling [ISEL], viability [lactate dehydrogenase (LDH release)], cell proliferation [proliferating cell nuclear antigen (PCNA)] and DNA synthesis (thymidine incorporation). The effects of EPO pre-treatment (5000U/kg) on renal morphology and function were also studied in rat models of unilateral and bilateral ischaemia–reperfusion (IR) injury. Results. In the in vitro model, hypoxia (1 % O2) induced a significant degree of PTC apoptosis, which was substantially reduced by co-incubation with EP