Referenced in: none

Automatically associated channels: Kv2.1

Title: Enhancement of GABA binding by the benzodiazepine partial agonist CGS9896.

Authors: B A Meiners, A I Salama

Journal, date & volume: Eur. J. Pharmacol., 1985 Dec 10 , 119, 61-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/3002818

Abstract
Compounds have been reported that act on the benzodiazepine receptor as full agonists (diazepam and CL218872), full antagonists (CGS8216 and RO15-1788), on partial agonists (CGS9896). We examined the effect of these compounds on [3H]GABA binding to membrane fragments from rat brain. Incubations were performed at 37 degrees C in a buffer containing EGTA to reduce free calcium ion levels. Centrifugation was then used to separate bound from free [3H]GABA. Diazepam caused a 20-45% enhancement of [3H]GABA binding and this effect was inhibited by 5 mM CaCl2. The magnitude of the enhancement of [3H]GABA by CL218872 was similar to that of diazepam. In contrast, the benzodiazepine antagonists, RO15-1788 and CGS8216 caused little enhancement of [3H]GABA binding. Finally, the partial agonist CGS9896 was distinguishable from both the benzodiazepine antagonists and full agonists by an intermediate level of enhancement of [3H]GABA binding. The extent of enhancement of [3H]GABA binding appears to be predictive of the pharmacological efficacy of compounds acting at the benzodiazepine receptor.