Pyrethroid insecticides and radioligand displacement from the GABA receptor chloride ionophore complex.
Radioligand binding displacement studies were conducted to determine the effects of Type I and II pyrethroids on [3H]flunitrazepam (FLU), [3H]muscimol (MUS), and [35S]t-butylbicyclophosphorothionate (TBPS) binding. Competition experiments with [3H]FLU and [3H]MUS indicate a lack of competition for binding by the pyrethroids. Type I pyrethroids failed to compete for the binding of [35S]TBPS at concentrations as high as 50 microM. Type II pyrethroids inhibited [35S]TBPS binding to rat brain synaptosomes with Ki values ranging from 5-10 microM. The data presented here suggest that the interaction of Type II pyrethroids with the gamma-aminobutyric acid (GABA) receptor-ionophore complex is restricted to a site near the TBPS/picrotoxinin binding site.
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D001643:Bridged Bicyclo Compounds / Q000378:metabolism; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003975:Diazepam / Q000378:metabolism; D005445:Flunitrazepam / Q000378:metabolism; D008297:Male; D009118:Muscimol / Q000378:metabolism; D009570:Nitriles; D026023:Permethrin; D011722:Pyrethrins / Q000378:metabolism*; D051381:Rats; D011963:Receptors, GABA-A / Q000378:metabolism*
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D009570:Nitriles; D011722:Pyrethrins; D011963:Receptors, GABA-A; C017160:cypermethrin; D009118:Muscimol; C017180:decamethrin; C017498:cismethrin; D026023:Permethrin; D005445:Flunitrazepam; C037476:tert-butylbicyclophosphorothionate; D003975:Diazepam; C017690:fenvalerate