镉对草鱼的急性毒性效应及SOD的影响

以静水生物测试法研究了氯化镉对草鱼的急性毒性效应及其肝胰脏、肾脏和鳃组织的超氧化物歧化酶(SOD)的影响.结果表明:镉对草鱼的急性毒性作用时间为24,48,72和96 h的半数致死质量浓度(LC50)分别是45.58,34.81,28.63和24.05 mg.L-1,因此镉对草鱼的生态毒性为高毒.Cd2+低浓度时,肝胰脏和肾脏组织SOD活性均为"先降后升再降",而Cd2+为高浓度时SOD活性始终处于被显著抑制(p<0.05);鳃组织在低Cd2+污染时SOD活性为"先降后升",而高浓度的Cd2+污染时其SOD活性为"先降后升再降".但是草鱼鳃组织的SOD活性明显低于肝胰脏和肾脏的SOD活性.

SOD Effect of Cadmium Chloride on Acute Toxicity of Grass Carp

The acute toxicity of cadmium chloride to grass carp was investigated by stagnophile testing, as well as the effect of superoxide dismutase systems (SOD) on grass carp's liver, kidney and gill tissues. The results showed that the LC50 for grass carp are 45.58, 34.81, 28.63 and 24.05 mg·L^-1 when the acting time of acute toxicity of cadmium chloride are 24, 48, 72 and 96 h, respectively. The high ecological toxicity of cadmium is thus proved to grass carp. The activity of SOD in grass carp's liver and kidney tissues decreases first then increases and decreases once again when Cd²⁺ presents low concentration pollution, while the activity of SOD is inhibited obvious all along (p<0.05) when Cd²⁺ presents high concentration pollution. However, the activity of SOD in grass carp's gill tissues decreases first then increases when Cd²⁺ presents low concentration pollution, while the activity decreases first then increases and then decreases once again when Cd²⁺ presents high concentration pollution. It was revealed that the activity of SOD in grass carp's gill tissues is much lower than in liver and kidney tissues.