运动对2,3,7,8-四氯二苯并二恶英急性暴露大鼠肝脏抗氧化能力的影响

Effect of Exercise on the Activity of Liver Antioxidant Ability in 2,3,7,8-Tetrachlorodibenzo-p-dioxin( TCDD)-Exposed Rats

观察8周中等强度游泳运动对2,3,7,8-四氯二苯并二恶英(2,3,7,8-tetrachlorodibenzo-p-dioxin,2,3,7,8-TCDD)急性暴露大鼠肝脏氧化应激的影响。以8周龄雄性Sprague Dawley大鼠为研究对象,将大鼠随机分为玉米油静养组(NC组)、玉米油运动组(EC组)、TCDD静养组(NT)和TCDD运动组(ET组)。将TCDD溶于玉米油中,NT和ET组大鼠按照10μg·kg-1(以单位体重计)腹腔注射TCDD,NC和EC组大鼠注射等量玉米油。正式实验开始后,EC和ET组大鼠进行运动(尾部负重5%游泳30min),每周运动5 d,共8周,NC和NT组大鼠不进行任何运动干预。8周后,称重并宰杀大鼠,收集血清和肝组织样本,待测血清天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的活性;肝组织丙二醛(MDA)含量,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及谷胱甘肽过氧化物酶(GSH-Px)的活性。将数据进行多因素方差分析,结果表明,染毒可升高大鼠血清AST的活性,增加肝脏MDA的含量,降低肝脏SOD、CAT和GSH-Px的活性;运动可降低大鼠肝脏GSH-Px的活性;染毒后运动可减少肝脏MDA的含量,升高肝脏SOD、CAT和GSH-Px的活性。研究表明,TCDD急性暴露可导致大鼠肝细胞功能受损,导致大鼠肝脏发生氧化应激。8周有氧运动改善TCDD急性暴露诱导的肝细胞损伤,改善肝脏氧化应激,这可能是运动改善TCDD肝毒性的机制之一。

The purpose of this study was to investigate the effects of moderate intensity exercise（8-week swimming） on the oxidative stress in the liver of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin（TCDD）-exposed rats. Forty, 2-month-old, male Sprague Dawley（SD） rats were randomly assigned to 4 groups, including normal control（NC）group, normal toxic（NT） group, exercise control（EC） group, and exercise toxic（ET） group. The rats in NT and ET groups were intraperitoneally injected with TCDD（dissolved in the corn oil, 10 μg·kg-1body weight）; and the NC and EC groups w ere injected w ith equivalent volume of corn oil. Then, the rats in EC and ET groups sw am for8 w eeks w ith a w eight of 5 % body w eight attached to the tails（30 min·d-1and 5 d per w eek）. After all the procedure, the body w eights of the rats were measured, the liver of the rats was obtained to determine the concentration of malonaldehyde（MDA）, and the activities of the superoxide dismutase（SOD）, catalase（CAT） and glutathione peroxidase（GSH-Px）. And the sera were collected to determine the activities of the aspartate aminotransferase（AST） and the alanine aminotransterase（ALT）. The results show that the AST activity and the MDA concentration increased, and the activities of SOD, CAT, and GSH-Px decreased in the NT groups compared to the NC group. In addition, the GSH-Px activity decreased in the EC group, while the MDA concentration decreased and the activities of SOD, CAT and GSH-Px increased. It can be conclude that acute exposure of TCDD could lead to hepatocyte damage, and consequently result in the oxidative stress in the live. Eight week of moderate intensity exercise may decrease the cell damage and the oxidative stress. Therefore, the improving effects of the exercise on the anti-oxidative capacity of the liver may be one of the mechanisms of its hepatic protective function against TCDD.