AIM:To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS:The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution. RESULTS:In our isolated blood-perfused rat liver model,pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury,as judged by the elevated aspartate aminotransferase activity. In addition,P-selectin antibody treatment did not significantly reduced hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However,total bile production after 120 min of perfusion was signifi cantly greater in P-selectin antibody-treated livers,compared to control livers. No signifi cant difference in P-selectin and ICAM-1 mRNAs and proteins,GSH,GSSG,and nuclear NF-κB was found between control and P-selectin antibody-treated livers. CONCLUSION:In conclusion,we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model. AIM: To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS: The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution. RESULTS: In our isolated blood-perfused rat liver model, pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury, as judged by the elevated aspartate aminotransferase activity. In addition, P-selectin antibody treatment did not significantly reduce hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However, total bile production after 120 min o f perfusion was signifi cantly greater in P-selectin antibody-treated livers, compared to control livers. No signifiant difference in P-selectin and ICAM-1 mRNAs and proteins, GSH, GSSG, and nuclear NF-κB was found between control and P-selectin antibody-treated livers. CONCLUSION: In conclusion, we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model.