镉对厚壳贻贝急性毒性及对其鳃抗氧化酶活性的影响

Effects of Cadmium on Antioxidant Enzyme Activity in Gill of Mytilus coruscus and Acute Toxicity of Cadmium on Mytilus coruscus

研究选用东海区常见种厚壳贻贝（Mytilus coruscus）开展了镉作用下的急性毒性和亚慢性毒性的实验研究。根据预实验结果设计了2.92、3.34、3.81、4.36、4.98 mg/L 5个Cd^2＋浓度梯度进行急性毒性实验,结果表明镉对厚壳贻贝24、48、72、96 h LC50（半数致死浓度）分别为4.85（4.30-5.47）、4.15（3.77-4.57）、3.55（3.25-3.89）、3.10（2.81-3.42）mg/L。厚壳贻贝于不同亚致死浓度镉（0.194、0.388、0.775mg/L）溶液中连续暴露8 d,结果显示,暴露初期鳃组织中SOD、CAT、GSH-Px的活性随镉浓度升高而升高,整个暴露期间三者均呈先升后降的规律。厚壳贻贝鳃中SOD、CAT、GSH-Px对水环境中镉反应敏感,且存在一定的剂量-效应关系,可尝试将三者共同作为指示海洋重金属污染的指标。

In the present study, two experiments are carried out to evaluate the acute toxicity and subchronic toxicity of cadmium on Mytilus coruscus, a common species in East China Sea. According to the results of pre-experiment five concentration gradients （2.92, 3.34, 3.81, 4.36, 4.98 mg/L）are designed to conduct acute toxicity test. The results indicate that 24, 4.8, 72 and 96 h LC50 values of cadmium on M. coruscus are 4.85 （4.30-5.47） mg/L, 4.15 （3.77-4.57） mg/L, 3.55 （3.25-3.89） mg/L, 3.10 （2.81-3.42） mg/L, respectively. The results show the activation of cadmium on SOD, CAT and GSH-Px activities in the gill increased with its concentration increasing, which are all first increased and then decreased, while M. coruscus exposed continuously in different sublethal concentrations of cadmium （0.194, 0.388, 0.775 mg/L） solution in eight days. In brief, SOD, CAT, GSH-Px are sensitive to cadmium in environmental water in the early exposure, possessing certain does-effect relationship during the whole exposure. SOD, CAT and GSH-Px in the gill of M. coruscus can be considered as potential biomarkers to indicate the heavy mental pollution.