脂多糖对化学诱癌大鼠抗氧化系统的选择性损害作用

目的：观察脂多糖对化学诱癌大鼠抗氧化系统的影响。方法：用０３ｇ／Ｌ硫代乙酰胺给大鼠饮用６个月，诱发肝硬化癌变模型。大鼠在实验前作脾切除造成肠源性内毒素血症或／和在肝硬化形成时给予外源性脂多糖。结果：无论是外源性或／和肠源性内毒素均可提高肝硬化大鼠内毒素血症水平和肝癌发生率增加趋势。肝内丙二醛（ＭＤＡ）含量、超氧化物歧化酶（ＳＯＤ）活性不同程度地增高、而谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）和过氧化氢酶（ＣＡＴ）活性呈降低趋势，并与ＭＤＡ浓度呈明显负相关（Ｐ＜００５）。结论：抗氧化酶类代谢紊乱、特别是ＣＡＴ活性降低可能与肝硬化癌变的发生发展有关

Selective impairment of lipopolysaccharide on antioxidant system in rat hepatocarcinogenesis induced by thioacetamide

AIM:To study the effect of lipopolysaccharide on antioxidant system in rat hepatocarcinogenesis.METHODS:Hepatocarcinoma in rats was induced by oral intake of 0.3 g/L thioacetamide(TAA) for six months.The TAA-induced rats were treated additionally with splenectomy before commencement of the experiment and/or administration of 8 mg/L lipopolysaccharide(LPS) underlying cirrhosis RESULTS:The intestinal endotoxin from splenectomy and/or exo-endotoxin from LPS oral administration elevated endotoxemia levels ( P <0 05) and increase hepatoma rate;The increased MDA content in liver was inversely correlated to the activities of GSH-Px and catalase (CAT) instead of SOD.CONCLUSION:The impaired GSH-Px and CAT possibly contributed to hepatocarcinogenesis in cirrhotic rats.