[Ion-dependency of the GABA-potentiating effects of benzodiazepine tranquilizers and harmane].
Experiments on an isolated spinal cord of 8-15-day-old rats have shown that one of the possible mechanisms of the GABA-potentiating action of the benzodiazepine tranquilizer, chlorodiazepoxide, may be a decrease in the intraneuronal concentration of Ca2+. This is evidenced by the enhancement of the GABA-potentiating action of chlorodiazepoxide under Ca2+ deficiency in the medium and in the presence of the blockers of the voltage-dependent Ca2+ ionic channels--Mn2+ and Co2+, and by the reduction of the effect in question under Ca2+ excess in the medium and in the presence of the K+ channels blockers--tetraethylammonium and 4-aminopyridine. The GABA-potentiating action of harmane is likely to be related to the blockade of the voltage-dependent K+ channels and elevation of the intracellular concentration of Ca2+.
D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D002707:Chlordiazepoxide / Q000494:pharmacology; D004357:Drug Synergism; D006247:Harmine / Q000031:analogs & derivatives / Q000494:pharmacology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D051381:Rats; D013116:Spinal Cord / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000470:Alkaloids; D014151:Anti-Anxiety Agents; D007473:Ion Channels; D006247:Harmine; D005680:gamma-Aminobutyric Acid; D002707:Chlordiazepoxide; C005010:harman
Ionnaia zavisimost' GAMK-potentsiruiushchikh éffektov benzodiazepinovykh trankvilizatorov i garmana.