Effects of methylprednisolone and its liver-targeted dextran prodrug on ischemia-reperfusion injury in a rat liver transplantation model

Purpose. To evaluate the effectiveness of a liver-targeted dextran prodrug (DMP) of methylprednisolone ( MP) in cold preservation-warm reperfusion injury associated with liver transplantation. Methods. The effects of donor pretreatment with single 5 mg/kg doses of MP or DMP on ischemia reperfusion damage to the liver were studied after 8 or 24 h of cold preservation in both isolated perfused rat liver (IPRL) and syngeneic orthotopic rat liver transplantation (OLT) models. Results. In IPRL studies, donor pretreatment with DMP, and to a lesser degree MP, significantly improved the uptake of hyaluronic acid (HA), a marker of endothelial cell function, following 8 h of cold preservation. However, neither pretreatment was protective after 24 h of preservation. In the OLT model using 24-h-preserved livers, the seven-day survival of untreated grafts was 50%. DMP pretreatment of donors significantly improved graft survival to 100%, whereas MP pretreatment was ineffective. Additionally, only DMP significantly increased the blood glucose concentrations and decreased the plasma concentrations of tumor necrosis factor-alpha after OLT. Other measured markers of liver injury were not affected by either pretreatment. Conclusions. Selective delivery of methylprednisolone to the liver as a donor pretreatment strategy improves 24-h preserved graft survival in the OLT model.