缺血预处理对减体积肝移植大鼠缺血再灌注损伤的保护作用

目的探讨缺血预处理（IPC）对减体积肝移植大鼠缺血再灌注损伤的保护作用及其机制。方法将36只成年雄性SD大鼠行50%减体积肝移植,随机分为对照组（Control）组和IPC组,检测术后2、6、24 h血清丙氨酸转氨酶（ALT）水平变化。检测术后24 h肝组织形态学变化、丙二醛（MDA）和超氧化物歧化酶（SOD）含量;检测髓性过氧化物酶（MPO）活性以反映中性粒细胞浸润情况;ELISA法检测肝组织中肿瘤坏死因子α（TNF-α）水平。结果与Control组比较,IPC组术后6、24 h ALT水平显著下降（P〈0.01）;组织病理学显示,Control组肝细胞明显空泡样变性伴局部坏死,小叶结构破坏,门脉周围水肿、充血,炎症细胞浸润明显,而IPC组损伤减轻;与Control组比较,IPC组MDA水平显著下降而SOD含量则明显增加（P〈0.01）,肝组织中TNF-α和MPO亦显著降低（P〈0.01）。结论IPC明显减轻减体积肝移植术后再灌注损伤,其机制部分与增强抗氧化、抑制脂质过氧化、减轻炎症反应密切相关。

Protective effect of ischemic preconditioning on ischemia reperfusion injury in reduced-size rat liver transplantation model

Objective To investigate the protective effect of ischemic preconditioning（IPC） on ischemia reperfusion in reduced-size liver transplantation model and explore its mechanism.Methods 36 adult male SD rats were randomly divided into two groups： 50% sized liver transplantation group（control group） and ischemic preconditioning group（IPC group）.Serum ALT levels were examined at 2,6 and 24 h postoperatively.24 h after reperfusion,the histopathological changes,the content of MDA and SOD in liver grafts were detected.The myeloperoxidase（MPO） activity was assayed to reveal neutrophil infiltration into the grafts,and the TNF-α levels were determined with enzyme-linked immunosorbent assay（ELISA）.Results Compared with control group,serum ALT levels were significantly lower 6 and 24 h after reperfusion in IPC group（P〈0.01）.Histopathological analysis showed disruption of lobular architecture,apparent hepatocelluar degeneration accompanied by focal necrosis;significant edema,congestion and inflammatory cell infiltration in periportal area 24 hours after reperfusion in the control group,whereas the injury was attenuated in IPC group.In IPC group,as compared to the control group,the MDA level significantly decreased while SOD level significantly decreased（P〈0.01）.Likewise,hepatic TNF-α levels and MPO activity at 24 hours after reperfusion significantly decreased（P〈0.01）.Conclusion IPC evidently ameliorated ischemia reperfusion injury in reduced-size liver grafts,and the protective mechanisms might be closely mediated in part by the enhancement of antioxidant ability,inhibition of lipid peroxidation,and down-regulation of inflammatory reaction