大鼠免疫性肝损伤的机制和低铁负荷的影响

目的　探讨超氧化物歧化酶 (SOD)在免疫性肝损伤中的作用以及低铁负荷的影响。方法　通过放血或去铁胺 (DFO)处理 ,建立低铁动物模型 ;采用卡介苗加脂多糖诱导法复制免疫性肝损伤模型 ;检测血清铁 (SI)、转铁蛋白 (TRF)、总蛋白 (TP)含量及天门冬氨酸氨基转移酶 (AST)活性 ;检测肝组织中丙二醛(MDA)含量、SOD活性和铁 (HIC)的变化。结果　与空白对照组比较 ,DFO对照组、放血对照组和肝损伤组SI显著降低。除DFO组外 ,其它组的TRF均降低。与其相应对照组比较 ,各损伤组AST增高 ,TP均降低 ;DFO损伤组和放血损伤组AST活性增高的幅度和TP含量的降低的幅度均小于单纯肝损伤组。与对照组比较 ,DFO对照组及放血对照组MDA均显著降低 ;各损伤组与其相应对照组比较 ,MDA含量均增高 ,SOD活性均降低。结论　在免疫性肝损伤时 ,肝组织SOD活性降低 ,脂质过氧化产物清除障碍 ,是肝细胞损伤的主要原因之一。低铁对肝细胞有保护作用 ,可能是由于铁催化的脂质过氧化过程减弱的结果

Putative mechanism of experimental immunological liver injury and influence of iron low-load on the injury in rat

Objective To investigate the effects of superoxide dismutase(SOD) and reducing iron load on experimental immunological liver injury in rat. Methods 48 male Wistar rats were divided into six groups randomly. The animal model of iron low-load was created by intravenation of deferoxamine(DFO) or phlebotomy respectively. Immunological liver damage model was reproduced by injection of lipopolysaccharide (LPS) and BCG (Bacilli Calmette Guein). The following parameters were determined such as serum iron (SI), transferrin (TRF) concentration, total proteins (TP) volume, the serum activities of asparatate aminotransferase (AST), and malondialdehyde (MDA) content, the activities of superoxide dismutase and iron deposition (HIC) in liver tissue extracts. Results In comparison with blank control group, the SI levels lowered (P<0.05) in pure DFO group, pure phlebotomy group and liver injury group. Compared with each own control groups, the serum activities of AST in all injury groups augmented and the levels of TP in them reduced significantly. The increased magnitude of the activities of AST and the decreased magnitude of TP levels in DFO injury group and phlebotomy injury group were less than those of pure injury group(P<0.05). In comparison with the control group, the MDA levels in pure DFO and phlebotomy groups declined significantly and the activities of SOD in them had no significant difference. Compared with each own control groups, the MDA levels augmented and the activities of SOD reduced significantly in all injury groups. Conclusion SOD activity reduces in immunological liver injury in rat. Iron low-load can mitigate the severity of liver injury.