Strychnine antagonizes GABA-evoked 36Cl- uptake in membrane vesicles from rat and rabbit cerebral cortex.

The uptake of 36Cl- into the fraction of membrane vesicles from rat and rabbit cortex and rabbit hippocampus was measured to investigate the selectivity of agonists and antagonists of inhibitory amino acid receptors coupled to chloride channels in the forebrain gamma-Aminobutyric acid (GABA) produced a dose-dependent 36Cl- uptake into membrane vesicles, whereas glycine and taurine were ineffective. The chloride uptake induced by GABA was inhibited in a dose-dependent manner by bicuculline and picrotoxin, established antagonists of GABAA receptors. GABA elicited chloride influx was also inhibited, with similar potency, by strychnine, thus indicating a limited selectivity of this glycine receptor antagonist.