Protection by pentoxifylline against graft failure from storage injury after orthotopic rat liver transplantation with arterialization

Abstract

Destruction of the endothelial cell lining and activation of Kupffer cells after reperfusion limits the safe storage of livers for transplantation surgery. Tumor necrosis factor-alpha (TNF) release by activated Kupffer cells may contribute to graft failure from storage injury. Accordingly, we evaluated whether pentoxifylline, which suppresses macrophage TNF release, would improve graft survival after orthotopic rat liver transplantation with arterialization. Livers from syngeneic Lewis rats were stored for 12–24 h in cold UW solution. Prior to implantation, the livers were flushed with cold Ringer's solution or warm Carolina rinse solution B. With either rinse, pentoxifylline treatment of graft recipients significantly improved graft survival. Combined use of pentoxifylline (50 mg/kg for 5 days) and Carolina rinse solution doubled the safe storage time to 24 h. Acidotic pH and antioxidants were essential components of Carolina rinse solution that acted synergistically with pentoxifylline. Pentoxifylline was also shown to suppress TNF release by lipopolysaccharide (LPS)-stimulated cultured rat Kupffer cells. Thus, pentoxifylline may protect against primary non-function and failure of grafts from storage injury by suppressing excessive TNF release by activated Kupffer cells. However, neutralization of TNF with excess anti-TNF antibody did not improve survival. This may mean that depletion of TNF is as deleterious as excess TNF production. Alternatively, other Kupffer cell secretions [e.g., interleukin-1 (IL-1), interleukin-6 (IL-6) and other cytokines] may be involved in the pathogenesis of graft failure. In conclusion, pentoxifylline could protect against graft failure from storage injury.