The optimal kidney preservation system and methods to ameliorate reperfusion injury are major factors in accomplishing successful graft function following transplantation. Ischaemia and reperfusion lead to cellular stress and the adaptive response may include the activation of genes involved in cellular protection and/or cell death by apoptosis. We investigated the expression of cytoprotective heme oxygenase-1 (HO-1), anti-apoptotic Bcl-2 and pro-apoptotic Bax after 6 h isolated organ perfusion in porcine kidneys that had been given 10 and 40 min warm ischaemic time. The level of HO-1 was shown to be significantly higher in the 10-min warm ischaemic group compared with 40-min group (0.90 +/- 0.03 vs. 0.83 +/- 0.03; P = 0.002). The levels of HO-1 showed a significant positive correlated with parameters of renal function, creatinine clearance, and renal blood flow and urine output (AUC; r = 0.8042, P = 0.03; r = 0.6028, P = 0.04; r = 0.6055, P = 0.04), demonstrating a possible protective role of this gene in this model of renal transplantation.