Cu^(2+)和Cd^(2+)对斑马鱼胚胎早期发育的联合毒性

Joint Toxicity of Cu^(2+) and Cd^(2+) to Early Development of Zebrafish Embryos

采用斑马鱼胚胎早期发育技术,测定Cu2+和Cd2+2种重金属对胚胎发育的毒性效应.以24h致死和72h胚胎孵化抑制为毒性终点,2种重金属的剂量-效应曲线可用Weibull函数或Logit函数有效描述,由最佳拟合函数计算得出半数致死浓度(LC50)或半数效应浓度(EC50)为毒性效应的评价标准,2个毒性终点的重金属毒性大小顺序均为Cu2+>Cd2+.应用浓度加和(CA)与独立作用(IA)2种模型,对72h孵化抑制率的无观测效应浓度(NOEC)配比混合物的联合毒性作用进行了预测,通过混合物试验观测数据的95%置信区间与CA模型和IA模型预测的剂量-效应曲线进行比较分析表明,2种模型都可以有效预测斑马鱼胚胎孵化的联合毒性.

The toxicities of two heavy metals Cu2 ＋ and Cd2 ＋ to embryo development were determined using the zebrafish embryo early development toxicity technique.The dose-response curves of the two heavy metals could be effectively characterized by the Logit and Weibull functions on the two toxicity endpoints of 24 h lethal rate and 72 h hatch inhibition rate.The median lethal concentration（LC50） and the median effect concentration（EC50） calculated by the best-fitted functions were used as the toxicity evaluation criteria.The toxicity order of the two heavy metals on the two observed toxicity endpoints according to the value of either LC50 or EC50 both showed that Cu2 ＋ Cd2 ＋.The joint toxicity was predicted using the mixture ratio of the non-observed effect concentration（NOEC） of 72 h hatch inhibition rate by two models of concentration addition（CA） and independent action（IA）,then compared with the 95% confidence intervals of the mixture experimental data.The results indicated that the two models could both predict joint toxicity of zebrafish embryo hatching effectively.