[Endogenous inhibitors of the specific binding of benzodiazepines in the cerebral cortex]. / Endogennye ingibitory spetsificheskogo sviazyvaniia benzodiazepinov v kore golovnogo mozga.

The nature of inhibitors of [3H]-diazepam (D) specific binding (SB) was studied in 2 fractions of acidic extract from bovine brain cortex. Preparative high-performance liquid chromatography (HPLC), mass spectrometry, UV and IR techniques identified hypoxanthine and inosine as inhibitors of SB D. These substances may participate in the neuronal activity control which is in part mediated by the benzodiazepine receptors.

[Pharmacokinetic characteristics of a new drug form of diazepam--sibazon]. / Osobennosti farmakokinetiki novoi lekarstvennoi formy diazepama--sibazona.

High-performance liquid chromatography, UV spectrometry and mass spectrometry have established that tablets of sibazon and seduxen contained equal quantities of pharmacologically active component diazepam. Radioligand assays revealed the diazepam blood serum levels twice as high 30 to 45 min after oral administration of seduxen than those after sibazon intake (p. less than 0.05). These differences were no more detectable after 2 to 3 hours. The pharmacokinetic differences could be accounted for by the properties of constituents.

[Endogenous inhibitors of specific benzodiazepine binding in the cerebral cortex of the bull]. / Endogennye ingibitory spetsificheskogo sviazyvaniia benzodiazepinov v kore golovnogo mozga byka.

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.

[Isolation of substances inhibiting the specific binding of imipramine and serotonin uptake from the brain of the bull]. / Vydelenie veshchestv, ingibiruiushchikhh spetsificheskoe sviazyvanie imipramina i zakhvat serotonina, iz golovnogo mozga byka.

Several fractions that inhibit specific binding of 3H-imipramine and reverse uptake of 3H-serotonin in rat brain synaptosomes were obtained by gel chromatography on Sephadex G-10 from an acidic extract of brain homogenates. The profiles of inhibition of 3H-imipramine specific binding and reverse uptake of 3H-serotonin were found to be in a good agreement. This finding suggests that substances identified in the brain extract may have both types of activities. Further investigations relative to the purification and identification of the substances isolated from bovine brain should be aimed at the search for endogenous ligands for the "imipramine receptor".