Objective: To investigate the effect of heme oxygenase 1 (HO-1) on the ischemic reperfusion injury (IRI) of bile duct in rat models after liver transplantation. Methods: 320 SD rats were equally and randomly divided into 5 groups, which were group A receiving injection of 3 x 10(8)/pfu/ml adenovirus (adv), group B with donor receiving Adv-HO-1 and recipient receiving Adv-HO-1-siRNA, group C with donor and recipient both receiving AdvHO-1, group D with donor receiving Adv-HO-1-siRNA and recipient receiving Adv-HO-1, and group E with donor and recipient both receiving Adv-HO-1-siRNA at 24 h before liver transplantation. Donor liver was stored in UW liquid at 4>degrees C followed by measuring HO-1 level by western blot before transplantation. On d1, d3, d7 and d14, serum and liver was isolated for analysis of liver function, inflammatory cell infiltration by H&E staining, ultrastructure of liver by transmission electron microscopy as well as the expression of HO-1, Bsep, Mrp2 and Ntcp by western blot. Results: Compared with group D and E, group B and C displayed improved liver function as demonstrated by lower level of ALT. AST, LDH, TBIL, ALP and GGT, increased secretion of TBA and PL as well as expression of transporter proteins (Bsep, Mrp2 and Ntcp), reduced inflammatory cells infiltration and liver injury. Conclusion: Our study demonstrated that overexpression of HO-1 in donor liver can ameliorate the damage to bile duct and liver, and improved liver function, suggesting HO-1 might be a new therapeutic target in the treatment of IRI after liver transplantation. (C) 2017 Elsevier Masson SAS. All rights reserved.