重金属离子对日本蟳血淋巴抗氧化酶(SOD,CAT,GPx)活力的影响

Effects of Heavy Metal Ions on the Antioxidant Enzymes of the Haemolymph of Crab Charybdis japonica

探讨重金属离子对日本的致毒机理,实验研究了4种重金属离子(Cu2+,Pb2+,Hg2+,Cd2+)对日本血淋巴SOD,CAT,GPx活力的影响。实验结果表明:4种重金属离子对日本血淋巴SOD,GPx活力影响显著(P<0.05),并在实验时间内均呈现峰值变化,而空白对照组变化不显著(P>0.05)。在低浓度重金属离子(Cu2+≤0.1mg.L-1,Pb2+≤0.5mg.L-1,Hg2+≤0.005mg.L-1,Cd2+≤0.05mg.L-1)作用下,各处理组SOD活力在实验时间内均呈激活状态,而高浓度处理组(Cu2+≥1mg.L-1,Pb2+≥5mg.L-1,Hg2+≥0.05mg.L-1,Cd2+≥0.5mg.L-1)SOD活力在暂时升高后逐渐下降,均在第9天后显著低于对照组(P<0.05),呈现一定的时间剂量效应;GPx活力在短时间被暂时激活后逐渐下降,除低浓度Cu2+(0.05,0.1mg.L-1),Pb2+(0.25,0.5mg.L-1)处理组外,各处理组酶活力在21d均下降到对照水平(P>0.05)或受到显著抑制(P<0.05),但未表现出明显的时间剂量效应;CAT活力未检出。4种重金属离子对日本血淋巴SOD,GPx活力的毒性大小为:Hg2+>Cd2+>Cu2+>Pb2+。血淋巴SOD活力变化可以作为日本毒理学的评价指标和重金属污染监测指标。

In order to clarify the toxic mechanism of heavy metal ions in the crab Charybdis japonica, this study was conducted to determine the effect of four kinds of metal ions （Cu^2 ＋ , Pb^2 ＋ , Hg^2＋ and Cd^2 ＋ ） on the superoxide dismutase （SOD）, catalase （CAT） and glutathione-peroxidas （GPx） activities of the haemolymph of Charybdis japonica. The results showed that： The SOD and GPx activities changed significantly （P 〈 0.05） among the treatments, and a peak value apperared during the experimental time while no significant changes were found in the control （P 〉 0.05）. All the SOD activities in the lower dose-groups （Cu^2 ＋≤0. 1mg·L^-1, Pb^2 ＋ ≤0.5mg·L^- 1, Hg^2 ＋ ≤0. 005mg·L^- 1, Cd^2 ＋ ≤0.05mg·L^- 1 ） were higher than the controls all the time. However, those in the higher dose-groups （Cu^2 ＋≥1 mg·L^- 1, Pb^2 ＋ ≥5mg·L^- 1, Hg^2 ＋≥0.05mg·L^- 1, Cd^2 ＋ ≥0.5mg·L^-1）, which increased temporarily and then decreased with prolonged exposure, were inhibited significantly after 9 days （P 〈 0.05 ） and showed obvious dose-time response relationship. The GPx activities showed a peak-like value in all the experimental groups, decreased to the level of those in the control groups or were inhibited significantly （P〈 0.05） after 21 days except the treatments of Cu^2＋ at dose levels 0.05 and 0. 1mg·L^-1 and Pb^2 ＋ at dose levels 0.25 and 0.5mg·L^-1, with no obvious dose-time response relationship showing. The CAT activities were not detected in all the treatments. The rank of toxicity to the antioxidant enzyme （SOD and GPx） of the haemolymph of Charybdis japonica was Hg^2＋ 〉Cd^2＋ 〉Cu^2＋ 〉Pb^2＋. The SOD activity could be used as a biomarker in evaluating the toxicology of Charybdis japonica and heavy metal contamination.