拟除虫菊酯对DPPC脂质体结构的影响

EFFECTS OF PYRETHROIDS ON THE STRUCTURE OF DPPC VESICLES

以DPH荧光偏振技术研究了含氰基和不含氰基两类拟菊酯与DPPC单层脂体间的相互作用。拟菊酯作用于膜的疏水区,降低DPPC脂质体的相变温度,加宽相变范围,随其浓度增加对磷脂有序排列的破坏加剧。氯菊酯具有干扰磷脂有序排列的能力,在凝胶态随其浓度的增加,P值降低幅度增大,在液晶态对P值基本无影响。氰基的导入,使北京菊酯、氯氰菊酯和杀灭菊酯既具有干扰磷脂有序排列的能力,又能产生荧光碰撞猝灭,在凝胶态,先降低P值,然后P值增大,当其浓度较大时,P值又略有下降,在液晶态,低浓度对P值影响不大,浓度较高时P值明显上升。

The interactions of permethrin, fenvalerate, cypermethrin and Beijing pyrethroid with membrane lipids in the form of DPPC vesicles have been studied by means of fluorescent membrane probe DPH. Pyrethroids had no absorbance of light at the excitation and emission wavelengths. Pyrethroids located in the interior hydrophobic regions of the lipid bilayer, differed in their effectiveness of lowering the phase transition temperature of DPPC and in their ability to broaden the temperature range of this transition. With the increase in the concentrations of pyrethroids, the effects of disordering hydrocarbon packing were increasedby pyrethroids. Fluorescence polarizations(P)were decreased in gel state, but not changed in fluid state by permethrin .The pyrethroids containing a cyano substitutent could not only disorder the hydrocarbon packing in the bilayer core, but also cause collisional quenching of DPH fluorescence. In gel state,P were decreased, then were increased and at last were decreased slightly again as the concentrations were increased. In fluid state P were not changed substantially at low concentrations and were increased obviously when the concentrations were higher.