内毒素对体外培养肝细胞脂质过氧化损伤的作用

In vitro study of endotoxin effects on lipid peroxidation injury of hepatocytes of rats

本研究通过体外实验,探讨了内毒素对肝细胞脂质过氧化损伤的作用以及SOD的保护效应。用分离的大鼠肝细胞与内毒素(500ng/ml)共同孵育,6h肝细胞MDA、LDH和SOD水平均显著上升(P<0.05～0.01),而且LDH和SOD升高早于MDA;预先将PMN经内毒素处理后,再与肝细胞共孵,激活的PMN能显著损伤肝细胞,引起肝细胞MDA升高和LDH释放增加(P<0.01),SOD活性下降(P<0.05)。给予SOD治疗能部分抑制PMN对肝细胞的损伤作用。上述结果提示,内毒素对PMN引起肝细胞的损伤具有增强作用,内毒素亦可直接诱导肝细胞脂质过氧化损伤,但其机制尚待进一步阐明。

The effects of endlbtoxin on lipid peroxidation injury of rat hepa-tocytes and the protective effects of exogenous superoxide dismutase (SOD) were studied in vitro.It was found that after the isolated rat hepatocytes and endotoxin (500 ng/ml) were incubated together for 6 hours,there was an obvious increase of malondialdlehyde (MDA) level and lactic dehydrogenase (LDH) and SOD activities,and the increase of LDH and SOD activities occurred earlier than that of MDA level.Polymorphonuclear neutrophils (PMN) after activated by endotoxin could destroy the hepatocytes and increase MDA level and LDH and SOD activities which could partially be inhibited with the pretreatment of exogenous SOD.These findings suggest that endotoxin can intensify the injurious effects of PMN on hepatocytes and it can also directly induce lipid peroxdatipn injury on hepatocyes but the mechanism was not clear.