【摘要】 以大型溞为受试生物,进行镉对大型溞48 h急性毒性试验、延迟效应试验和21 d慢性毒性试验,并研究不同质量浓度和处理时间的镉暴露下,大型溞关键抗氧化酶-超氧化物歧化酶（SOD）的活性变化.结果表明:镉的传统48 hLC₅₀大于完全48 hLC₅₀,以急性毒性为基础的生态危险性评价可能存在"欠保护"的问题;21 d慢性暴露对大型溞的生长及繁殖均产生影响,其中第1次生产时间和产子总数量是表征镉对大型溞繁殖毒性的最灵敏的生理参数;镉暴露中,SOD活性表现为低浓度诱导、高浓度抑制,且随镉浓度的变化反应灵敏,可以作为镉暴露的生物标志物.更多还原

【Abstract】 The acute（ 48 h） and chronic（ 21 day） toxic tests of cadmium were done by using Daphnia magna as test organism,and the activities of superoxide dismutase（ SOD） of Daphnia magna exposed to cadmium with different concentrations and various exposure times were measured. Results showed that traditional 48 h LC₅₀was greater than complete 48 h LC₅₀ and the ecological risk assessment based on the acute toxicity could be owed"protection".In the chronic test,it was indicated that the growth and fecundity of D.magna were all affected by cadmium exposure.The first birth time and the total number of eggs were the most sensitive parameters for the chronic exposure of cadmium.The activity of SOD was induced initially and inhibited afterwards and responsive.SOD could be used as biomarker of cadmium exposure.更多还原