Objective：To explore the impact and significance of hypoxia preconditioning on the activation of serum endotoxin after orthotopic liver autotransplantation in rats.
Methods：A modified orthopotic liver autotransplantation model was used to study the ischemia reperfusion injury in liver transplantation.Sprague-Dawley rats were randomly divided into the following three groups: normal control(NC)group, autotransplantation (AT)group,and hypoxia preconditioning(HP)group; there were 24 rats in each group. HP Group was given an 8% oxygen-mixed gas for 90 minutes before the operation. At 1,6 and 12 hours after the operation, the rats were killed and the following tests were conducted: (1) blood was drawn to determine the levels of ALT and AST; (2)Intestinal tissue was sampled to observe the changes of the microstructure and ultrastructure of the intestinal cells under optical microscopy and transmission electron microscope;(3) ELISA kits were used to measure serum endotoxin.
Results：The serum levels of ALT, AST and  endotoxin of HP group were significantly lower than those of AT group (P＜0.05) at 1,6 and 12 hours after the orthopotic liver autotransplantation. Injury of the intestinal mucosal of HP group was significantly less than that of AT group, and injury of the mitochondria of HP group was significantly less than that of AT group.
Conclusions：HP can reduce the level of serum endotoxin in orthotopic liver autotransplantation in rats by protecting the intestinal mucosa, decreasing translocation of intestinal endotoxin, and thus mitigating the damage of transplanted liver.This may have some relation to reducing the injury of the mitochondria after ischemia and hypoxia, improving the energy supply of cells and improving the ability of cells to resist hypoxia.