γ-Aminobutyric acid activation of36Cl-flux in rat hippocampal slices and its potentiation by barbiturates

摘要: Abstract γ-Aminobutyric acid (GABA) increases the rate of36Cl- efflux from preloaded rat hippocampal slices in a dose-dependent manner (EC50: 400 μM). This action has pharmacological specificity expected of activation GABA receptor that it is mimicked by agonists muscimol and 3-aminopropanesulfonic acid, blocked antagonists bicuculline picrotoxinin. uptake inhibitors, nipecotic 2, 4-diaminobutyric fail to increase36Cl- flux. Pentobarbital produces (EC50 = 1.5mM) with maximal response greater than GABA. The effect pentobarbital can be 1, 3-dimethylbutylbarbiturate, secobarbital, (+)hexobarbital but not (−)hexobarbital, other active barbiturates also potentiate Phenobarbital does have any independently or combination It suggested increases36Cl- permeability postsynaptic which turn functionally copupled barbiturate receptor.