己烯雌酚对染镉草鱼GSH-Px、SOD和MDA影响的研究

Effect of Diethylstilbestrol on GSH-Px, SOD and MDA of Grass Carp Exposed to Cadmium

通过鱼缸染毒实验,研究了己烯雌酚(DES)对染镉(Cd)草鱼(Ctenopharyngodon idellus)抗氧化能力的影响。将实验草鱼(体长(6.0±1.0)cm,体重(3.0±0.5)g)随机分为5组,Ⅰ为空白组(0.00mg·L-1Cd+0.00mg·L-1DES),Ⅱ为单独Cd处理组(1.46mg·L-1Cd+0.00mg·L-1DES),Ⅲ(1.46mg·L-1Cd+1.00mg·L-1DES)、Ⅳ(1.46mg·L-1Cd+2.00mg·L-1DES)、Ⅴ(1.46mg·L-1Cd+3.00mg·L-1DES)为联合处理组。在染毒24、72和120h时测定草鱼肝胰脏谷胱甘肽过氧化物酶(GSH-Px)活性、超氧化物歧化酶(SOD)活性和丙二醛(MDA)的含量。结果表明,Ⅲ组的抗氧化酶活性(GSH-Px,SOD)和抗氧化指数(GSH-Px/MDA)高于Ⅱ组,其中GSH-Px活性达显著(P<0.05),SOD活性在染毒120h时具显著性(P<0.05),抗氧化指数在72h和120h时达极显著(P<0.01);其MDA含量低于Ⅱ组,在72h和120h时差异显著(P<0.05)。表明DES在1.00mg·L-1浓度时对Cd具有显著的拮抗效应,增强了草鱼的抗氧化能力。Ⅳ、Ⅴ组与第Ⅲ组相比,抗氧化酶活性呈下降趋势,GSH-Px/MDA显著降低(P<0.05),MDA含量有所上升。说明随着DES浓度的增加,拮抗效应降低,抗氧化能力减弱。另外,随着染毒时间的延长,Ⅱ组的GSH-Px活性和抗氧化指数下降,MDA含量上升;Ⅲ组的抗氧化酶活性(GSH-Px,SOD)在120h时增强,抗氧化指数上升,MDA含量降低。

The effect of diethylstilbestrol （DES） on antioxidation in hepatocyte of grass carp （Ctenopharyngodon ideUus） exposed to cadmium （1.46 mg·L^-1） was investigated. Grass carps （6.0＋1.0 cm long, 3.0＋0.：5 g weight） were randomly divided into 5 groups, as control group I （0.00 mg·L^-1Cd＋0.00 mg·L^-1 DES）, single Cd group Ⅱ （1.46 mg·L^-1Cd＋0.00 mg·L^-1 DES）, experimental groups m （1.46 mg·L^-1Cd＋l.00 mg·L^-1 DES）, IV（1.46 mg.L-1 Cd＋2.00 mg·L^-1 DES） and V （1.46 mg·L^-1 Cd＋3.00 mg·L^-1 DES）. The activities of glutathione peroxidase （GSH-Px） and superoxide dismutase （SOD） and the content of malondialdehyde （MDA） in hepatocyte of grass carp were measured after 24 h, 72 h and 120 h exposure. Both the activities of antioxidative enzymes （GSH-Px, SOD） and the antioxidation index （GSH-Px/MDA） of the experimental groups （Ⅲ） were higher than those of the single Cd group （ Ⅱ ）： the activity of GSH-Px increased remarkably （P〈0.05）, and that of SOD reached significant level after 120 h exposure （P〈0.05）, the same as GSH-Px/MDA after 72 h and 120 h exposure （P〈0.01）. The content of MDA was lower, showing significant difference after 72 h and 120 h exposure （P〈0.05）. Such results suggested that DES （1.00 mg·L^-1） had an evident antagonistic effect on Cd, thus improved antioxidation in grass carp （Ctenopharyngodon idellus） effectively. Compared with experimental group （Ⅲ）, in the experimental groups （IV, V）, the activities of antioxidative enzymes（GSH-Px, SOD） decreased, and GSH-Px/MDA dropped prominently （P〈0.05）and the content of MDA increased, indicating that the antagonistic effect and antioxidation descended as the concentration of DES increased. And as the exposure time extending, the activity of GSH-Px and GSH-Px/MDA of the single Cd group （ Ⅱ ） decreased with rising content of MDA, and in the experimental group （Ⅲ）, the activities of antioxidative enzymes （GSH-Px, SOD） increased after 120 h exposure with increasing of GSH-Px/MDA and decreasing of MDA.