An endogenous substance /ES/ obtained from porcine brain /MW~3000/ partially inhibited the specific 3H-diazepam binding in the P2-fraction but not in the synaptic membrane fraction of rat brain. ES inhibited specific 3H-GABA binding to synaptic membranes in a dose-related manner. Intraamygdaloid injection of diazepam fully inhibited the convulsions evoked by systemic administration of pentylenetetrazol in the rat. This anticonvulsant action of diazepam was antagonized by a previous intraamygdaloid injection of ES but not of myoglobin. ES does not seem to be an endogenous ligand of benzodiazepine receptors; it probably exerts its effect via GABA receptors.
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience