超氧化物歧化酶在大鼠免疫性肝损伤中的作用

Effect of Superoxide Dismutase on Experimental Immunological Liver Injury in Rat.

目的 探讨超氧化物歧化酶(SOD)与免疫性肝损伤的关系及低铁负荷对肝细胞损伤的影响。方法 采用放血或去铁胺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、转铁蛋白、总蛋白含量及天门冬氨酸氨基转移酶(AST)活性,肝组织中丙二醛含量、SOD活性和铁含量的变化;留取肝组织做组织病理学检测。结果 ①低铁处理对照动物的血清铁均低于空白对照组;肝损伤动物的血清铁和转铁蛋白均低于其相应的对照组。②各损伤组动物AST活性均高于相应对照组,而总蛋白均低于相应对照组;低铁处理肝损伤动物的AST活性增高的幅度和总蛋白含量的降低幅度均小于单纯肝损伤组。③低铁处理对照动物的丙二醛小于空白对照组;各损伤组动物的丙二醛大于相应对照组,而SOD的活性均低于相应对照组。结论 肝组织SOD活性降低,脂质过氧化物清除障碍,是免疫性肝细胞损伤的主要原因之一;低铁负荷对肝细胞有保护作用。

Objective To investigate the relation between superoxide dismutase (SOD) to hepatocyte injury and influence of 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 Bacillus Calmette Guerin (BCG).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 in liver tissue extracts. Results ① The SI levels in the control group of iron low-load were lower than that of blank control group (P<0.05); the levels of SI and TFR in liver injury groups were lower than those of their own control.②The serum activities of AST in all injury groups were higher than those of their own controls, but the levels of TP in them were lower; 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 that of pure injury group (P<0.05).③The MDA levels in the control groups of iron low-load were lower than that of blank control group; the MDA levels in all injury groups were higher than those of their own controls, but the activities of SOD were lower. Conclusion That SOD activity reduces is one of the major reasons for the immunological liver injury in rat.Reduction in iron load can mitigate the severity of liver injury.