氰戊菊酯对肟硫磷毒物代谢动力学的影响

Effect of fenvalerate on the toxicokinetics of phoxim

目的 探讨在混配农药中氰戊菊酯对肟硫磷毒物代谢动力学的影响。方法 SD大鼠ig 6 6mg·kg-1等毒配比的肟硫磷与氰戊菊酯的混配农药 ,采用正相高效液相色谱法 ,测定血清和脑组织匀浆中的肟硫磷。结果 血清毒物浓度 时间曲线符合一级吸收一室开放模型 ,肟硫磷的代谢动力学参数为ka =4 33h-1,ke =0 0 7h-1,tp =1 41h ,与等毒单药肟硫磷染毒 (ka =1 87h-1,ke =0 47h-1,tp =1 2 6h)相比 ,氰戊菊酯明显增加肟硫磷的吸收速率 ,延长消除相半衰期 ,使机体对肟硫磷的代谢降解速率减慢。结论 氰戊菊酯能竞争性结合体内有限的毒物代谢酶 ,从而增加肟硫磷毒效应。

Objective To make an inquiry about the effect of fenvalerate on the toxicokineticsof phoxim,in order to lending more scientific data in the control of mixed pesticidepoisoning.Methods The biological samples were extracted with ethylacetate,then concentrated,volumecalibrated and directly injected into intake valve of a high performance liquid chromatography(HPLC) with a obverse phase chromatographic column of Lichrosorb Si 60 and a mobile phase of tetrahydrofuran petroleum ether(1 4∶98 6,v/v)for determination of phoxim content in serum and brain homogenate.Thereby,the toxicokinetic profile of phoxim administrated orally in rats was illustrated.Results After 66 mg·kg -1 (about 1/5 LD 50 dose)orally administration of the mixed pesticides (phoxim∶fenvalerate=10 5∶1,m/m),the concentration time curve of serum toxins was well fitted to the one compartment open model with 1st order absorption.Toxicokinetic parameters calculated from this model,were ka=4 33h -1 ,ke=0 07h -1 ,tp=1 41h.As compaing with that exposed to single drug,the absorption rate of phoxim was significantly increased and the half life time of elimination phase was delayed,suggesting that fenvalerate might slow the metabolic degeneration of phoxim.Conclusion The toxic effect of phoxim would be increased.Because of the competitive conjugation with limited metabolic enzymes between phoxim and fenvalerate,the toxicity of phoxim would increase by the combined administration of fenvalerate.