运动对急性暴露于2,3,7,8-四氯二苯并二恶英大鼠肝组织酶活性的影响

The Effect of Exercise on the Activity of Liver Microsomal Oxidase in2,3,7,8-Tetrachlorodibenzo-p-dioxin( TCDD)-Exposed Rats

为了研究运动对2,3,7,8-四氯二苯并二恶英(2,3,7,8-TCDD)急性暴露大鼠肝组织酶活性的影响,将40只雄性Wistar大鼠随机分为正常对照组(NC)、染毒组(NT)、运动对照组(EC)、运动染毒组(ET)。染毒组(NT组与ET组)腹腔注射10μg·kg-1(以单位体重计)的TCDD,对照组(NC组与EC组)腹腔注射等量的玉米油;NT、NC组静养4周,ET、EC组运动(尾部负重5%游泳30分钟)4周。4周后,称重并宰杀大鼠,分离肝组织,称重后-80℃保存待测7-乙氧基异吩恶唑酮脱乙基酶(EROD)、7-乙氧基香豆素-O-脱乙基酶(ECOD)及芳香烃羟化酶(AHH)的活性。将数据进行多因素方差分析(MAVONA)处理,结果表明,染毒可降低大鼠体重,增加肝湿重和肝相对重量、增加EROD、ECOD活性;运动可增加大鼠肝相对重量、增加AHH的活性;染毒后运动可降低EROD、ECOD的活性。结论:急性10μg·kg-1(以单位体重计)TCDD染毒后4周可增加大鼠肝相对重量;4周的运动能有效降低TCDD对EROD、ECOD活性的激活作用。

The aim of the present study was to investigate the effects of exercise on the activity of liver microsomal oxidase in acute 2,3,7,8-TCDD-exposed rats. Forty male Wistar rats were randomly divided into four groups： normal control （NC）, normal toxic （NT）, exercise control （EC）, and exercise toxic （ET）. The rats in NC and ET groups were intmperitoneal injection of 2,3,7,8-TCDD （10 μg.kg-1）; the NC and EC animals were administered with equivalent volume of coin oil, and the rats in exercise groups were submitted to swimming for 30 min.d-1 with 5% weights attached to tails. After 4 weeks, the rats were sacrificed and the livers were imme-diately isolated and weighted. The lobe of each liver was kept at -80 ℃ for detecting the activity of hepatic microsomal enzymes. The results were statistically analyzed using MANOVA. A decreased body weight together with increased liver weight, relative liver weight, and the activities of 7-ethoxyresomfm O-deethylase （EROD） and 7-ethoxycoumarin O-deethylase （ECOD） were observed in toxic group; an increased relative liver weight and the activity of aryl hydrocarbon hydroxylase （AHH） were observed in exercise group; and exercise could effectively prevent the activation of 2,3,7,8-TCDD on the activities of EROD and ECOD. The results suggest that acute exposure to 2,3,7,8-TCDD can increase the relative liver weight, and exercise can effectively prevent the activation of 2,3,7,8-TCDD on the activities of EROD and ECOD.