Abstract: Objective Acute renal dysfunction is a frequent complication after cardiacsurgery with cardiopulmonary bypass (CPB). This experiment was designed to investigate the expressions of NF-κB P65 and ICAM-1 in renal tissue of rats undergoing cardiopulmonary bypass, and the protective mechanisms of erythropoietin(EPO). Methods 30 male Sprague-Dawley rats were randomly divided into three groups: sham, CPB, EPO (3000U/kg EPO). Blood samples were collected at the beginning(T0) and the end of CPB(T1), and 0.5(T2), 1 h(T3), 2 h(T4) and 24 h(T5) after CPB for assays of serum creatinine. Renal samples were obtained 24 h after the operation for the determination of NF-κB P65, ICAM-1，and for histologic examination. Results Compared with those of the CPB group, the levels of serum creatinine were lower in EPO group (P<0.05 )．EPO had effective inhibitory effects on the expression of NF-κB P65 and ICAM-1 in renal tissues 24 h post-CPB (P<0.05 ), Histopathologic ?ndings of the CPB group con?rmed that there was renal impairment by cast formation and tubular necrosis in the tubular epithelium.These changes were markedly reversed in EPO group. Conclusion The expression of NF- B and ICAM-1 increased obviously in renal tissue of rats undergoing cardiopulmonary bypass, EPO can attenuate renal injury by inhibiting the activation and expression of NF-κB P65 and reduce the expression of ICAM-1.

Key words: Key words Erythropoietin, Cardiopulmonary bypass, NF-κB P65, ICAM-1, Rat