两种蜜蜂头部乙酰胆碱酯酶对杀虫药剂敏感度比较

通过对抑制动力学常数和抑制时间进程曲线的测定,比较了中华蜜蜂Apis cerana cerana Fabricius和意大利蜜蜂Apis mellifera ligustica Spinola头部乙酰胆碱酯酶(acetylcholinesterase,AChE)对几种有机磷和氨基甲酸酯类杀虫药剂的敏感度。抑制时间进程曲线显示,意大利蜜蜂头部AChE对毒扁豆碱、灭多威、敌敌畏的敏感度高于中华蜜蜂,而两种蜜蜂对残杀威、硫双灭多威、甲胺磷及久效磷的敏感度没有明显差异。意大利蜜蜂头部AChE对毒扁豆碱、残杀威、硫双灭多威、克百威以及丁硫克百威的双分子速率常数(Ki)值分别为4.003×106、5.744×104、5.249×104、1.986×106和5.492×104 (mol/L)-1 ·min-1,均高于中华蜜蜂对这几种杀虫药剂的Ki值,后者分别为3.403×106、4.633×104、4.233×104、1.262×106和5.072×104 (mol/L)-1 · min-1。但中华蜜蜂头部AChE对灭多威的Ki值却高于意大利蜜蜂,前者为10.408×104,后者为4.872×104(mol/L)-1 ·min-1。对AChE被抑制后恢复速率(K3)的测定结果表明,中华蜜蜂头部AChE被残杀威和硫双灭多威抑制后恢复的速率显著低于意大利蜜蜂,但两种蜜蜂被毒扁豆碱、灭多威、克百威和丁硫克百威抑制后恢复的速率差异不显著。

Comparison of the Head Acetylcholinesterase Sensitivity to Insecticides between Two Honeybee Populations

The sensitivities of acetylcholinesterase (AChE) from heads of Apis cerana cerana Fabricius and Apis mellifera ligustica Spinola to organophosphorus and carbamate insecticides were investigated by determining the inhibiting kinetic constants (K_</em>i, K₂, K_a and K₃) and the time-course curve of inhibition. The time-course curve of inhibition indicated that the sensitivities of AChE from head of A. mellifera ligustica to eserine, methomyl and dichlorovos were higher than that from head of A. cerana cerana. However, there was no significant difference of the AChE sensitivities to propoxur, thiodicarb, methamidophos and monocrotophos between both bees. The bimolecular reaction constants (K_i) of AChEs from A. mellifera ligustica and A. cerana cerana were 4.003×10⁶ and 3.403×10⁶ (mol/L)^-1 ·min^-1 for eserine, 5.744×10⁴ and 4.633×10⁴ (mol/L)^-1 · min^-1 for propoxur, 5.249×10⁴ and 4.233×10⁴ (mol/L)^-1 · min^-1 for thiodicarb, 4.872×10⁴ and 10.408×10⁴ (mol/L)^-1 · min^-1for methomyl, 1.986×10⁶ and 1.262×10⁶ (mol/L)^-1 · min^-1 for carbofuran,and 5.492×10⁴ and 5.072×10⁴ (mol/L)^-1 · min^-1 for carb osulfan, respectively. However, methomyl was more potentially inhibiting AChE from A. cerana cerana than that from A. mellifera ligustica. The value of K_i was 10.408×10⁴ and 4.872×10⁴ (mol/L)^-1 · min^-1 in A. cerana cerana and in A. mellifera ligustica, respectively. The reactivation rates of AChE inhibited by eserine and methomyl were higher in A. cerana cerana than in A. mellifera ligustica, however, when inhibited by propoxur, thiodicarb, carbofuran and carbosulfan, the former was lower than the latter.