等效面法分析3种氨基甲酸酯类农药对乙酰胆碱酯酶的联合作用

Combined Effects of Three Carbamate Pesticides on Acetylcholinesterase Analyzed by Equivalent-surface Method

为了更好地评估与预测三元混合物的毒性相互作用,以3种氨基甲酸酯类农药残杀威、灭多威、速灭威为研究对象,应用均分等效面设计(EESD)法配制三元混合物,应用直接均分射线设计法(EquRay)配制两两混合的二元混合物,测定混合物对乙酰胆碱酯酶(AChE)的抑制效应,基于三角形的3次插值方法构建三元混合物在20%、50%、80%效应的等效面,以浓度加和(CA)与独立作用(IA)为参考模型分析混合物的毒性相互作用。结果表明,Weibull函数能良好地拟合3种氨基甲酸酯类农药及其混合物对AChE的浓度-效应数据(R2>0.99,RMSE<0.03)。基于等效面分析,残杀威、灭多威、速灭威的三元及二元混合物毒性符合CA模型,呈现加和作用,而IA轻微高估了混合物的毒性。共毒系数法也证实这3种氨基甲酸酯类农药呈现加和作用。回归分析发现三元混合物毒性(pECx)与速灭威的浓度分数具有良好的负相关关系。均分等效面设计法与等效面分析法可用于有效评估三元混合物的联合毒性。

In order to better assess and predict the combined toxicity of ternary mixture, three carbamate pesticides including propoxur, methomyl and metolcarb were selected as mixture components. The equipartition equivalent-surface design（EESD） method was used to design ternary mixtures, and the direct equipartition ray design（EquRay） was used to design binary mixtures. The toxicities of these mixtures inhibiting acetylcholinesterase were determined using the microplate toxicity analysis method. The equivalent-surfaces at 20%, 50% and 80% effects were constructed based on the triangle-based cubic interpolation method. The concentration addition（CA） and independent action（IA） as the additive reference models were used to analyze the toxic interaction. The results showed that the Weibull function fit well the concentration-response data of the three pesticides and their mixtures with R20.99 and RMSE0.03. Based on the equivalent-surface analysis, the toxicities of ternary and binary mixtures of propoxur, methomyl, and metolcarb conformed to the CA prediction, showing an additive effect, while the IA prediction slightly overestimated the mixture toxicity. The method of co-toxicity coefficient also confirmed this additive effect of propoxur, methomyl, and metolcarb. Meanwhile, it was found that there was a good negative correlation between the ternary mixture toxicity（pECx） and the concentration proportion of metolcarb. The equipartition equivalent-surface design method and equivalent-surface analysis method could be effectively used to analyze the joint toxicity of ternary mixture.