低氧预适应对自体原位肝移植大鼠血清内毒素的影响

目的 探讨低氧预适应(HP)对大鼠自体肝移植后血清内毒素的影响.方法 采用改良的自体肝移植模型进行研究.将SD大鼠随机分为正常对照组(NC)、自体肝移植(AT)和低氧预适应+AT(HP)3组,每组24只.HP组术前用8%氮氧混合气体处理90 min.各组分别于术后1,6,12 h处死大鼠取肠标本,抽血检测ALT和AST水平;在光镜及透射电镜下观察各组小肠黏膜损伤程度及线粒体超微结构改变;同时应用ELISA试剂盒测定大鼠血清内毒素水平的变化.结果 HP组血清ALT,AST及内毒素水平均显著低于AT组,但高于NC组,差异均有统计学意义(P＜0.05);光镜下 HP组小肠黏膜损伤程度明显低于AT组;透射电镜下HP组线粒体损伤较AT组明显减轻.结论 HP可减轻肝IRI对肠道黏膜的损伤,减少了肠道内毒素移位而降低肝移植大鼠血清内毒素水平,从而减轻内毒素对移植肝功能的影响,其机制可能与减轻线粒体结构损伤,减轻缺血缺氧后线粒体功能障碍,改善细胞的供能,提高细胞的抗缺氧能力有关.

Impact and significance of hypoxia preconditioning on serum endotoxin |in orthotopic liver autotransplantation in rats

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.