[Endogenous inhibitors of specific benzodiazepine binding in the cerebral cortex of the bull].

Chromatography of an acidic extract from bovine brain cortex on a Sephadex G-10 column demonstrated 7 fractions capable of inhibiting specific binding of 3H-diazepam to brain cortex membranes. It was established by ultrafiltration that the molecular weights of the inhibitors were not higher than 5000 dalton. Scatchard analysis of 4 main fractions has revealed a type of inhibition similar to the competitive one. Activity of all the fractions remained unchanged after pronase treatment.