硒对大鼠肝脏超氧阴离子和羟自由基的作用

Effects of selenium on superoxide anion and hydroxyl free radical in rat liver

目的研究离体和在体染毒条件下亚硒酸钠对大鼠肝组织超氧阴离子 (·O-2 )和羟自由基 (·OH)生成的影响。方法 选用雄性Wistar大鼠。体外实验时 ,制备肝匀浆 ,在反应体系中加入亚硒酸钠使剂量分别达到 2 185 ,8 75 0和 35 0 0 0 μmol/L。采用常规方法测定·O-2 和·OH。体内实验时 ,用 0 75 ,1 5 0和 3 0 0mg/kg的亚硒酸钠 ,腹腔注射染毒。采用电子自旋共振测定·O-2 和·OH。结果 在体外染毒时 ,2 185 μmol/L的亚硒酸钠对大鼠肝组织产生抗氧化应激作用 ,使过氧化脂质 (MDA)、·O-2 和·OH的生成量明显下降 ,但 8 75 0和 35 0 0 0 μmol/L的亚硒酸钠则诱导大鼠肝组织产生明显的氧化应激 ,使·O-2 和·OH的生成量显著升高。在体内染毒时 ,0 75 ,1 5 0和 3 0 0mg/kg的亚硒酸钠均可引起大鼠肝组织·O-2 和·OH的产生量显著增加。结论 适宜剂量的亚硒酸钠抑制自由基生成 ,具有抗氧化作用 ,而较高剂量的亚硒酸钠则使自由基生成增多 ,导致明显的氧化应激。

Objective To study the effects of sodium selenite on production of superoxide anion( ·O - 2)and hydroxyl free radical( ·OH) in rat hepatocytes in vivo and in vitro.Methods Sodium selenite at the doses of 2 185,8 750 and 35 00、μmol/L acted respectively in male Wistar rat′s hepatocellular homogenate in vitro,superoxide anion( ·O - 2)and hydroxyl free radical( ·OH) were measured with regular methods.Studied in vivo,sodium selenite at the doses of 0 75,1 50 and 3 00、mg/kg were given to rats by i.p.,superoxide anion( ·O - 2)and hydroxyl free radical( ·OH)were measured with Electron Spin Resonance(ESR).Results Studied in vitro, sodium selenite at the dose of 2 185、μmol/L could decrease the production of MDA,superoxide anion( ·O - 2)and hydroxyl free radical( ·OH)significantly;While sodium selenite at 8 750 and 35 000、μmol/L respectively,selenium could increase the production of MDA,superoxide anion( ·O - 2)and hydroxyl free radical( ·OH) significantly.Studied in vivo, sodium selenite at the doses of 0 75,1 50 and 3 00、mg/kg could promote the formation of superoxide anion( ·O - 2)and hydroxyl free radical( ·OH)obviously.Conclusion Selenium at the certain dose could inhibit the production of free radicals and improve the state of oxidative stress,but selenium at relative high dose could increase the formation of free radicals and result in oxidative stress significantly in rat hepatocytes.