PYRETHROID- AND DDT-EVOKED RELEASE OF GABA FROM THE NERVOUS SYSTEM IN VITRO

摘要: Abstract Previous electrophysiological experiments have shown that the pyrethroids and DDT cause depolarisation of nerve membranes by prolonging inward sodium current; in this they resemble alkaloid veratridine, which is known to interact with channel mammalian neurones, causing an influx ions results transmitter release. We report effect three insecticides (DDT two - deltamethrin permethrin) on release from guinea-pig synaptosomes. The synaptosomes were maintained a superfusion system preloaded [3H]-γ-Aminobutyric acid ([3H]-GABA). radioactivity released comprised [3H]-GABA volatile component thought be tritiated water. All caused concentration-dependent increase [3H]-GABA, only minor effects water suggesting was specific. Deltamethrin more active than either permethrin or DDT. For deltamethrin, maximal response seen at ~10–5M resulted 27% radioactivity; EC50 ~10–7M threshold lower 10–8M. Tetrodotoxin (TTX) abolished substantially reduced showing specifically channel. GABA evoked largely independent external calcium concentration entry into synaptosome not necessary requirement for their action.