Stimulation of benzodiazepine receptor binding by gamma-aminobutyric acid.
- 1 February 1979
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 76 (2), 1004-1006
- https://doi.org/10.1073/pnas.76.2.1004
Abstract
The effect of the neurotransmitter GABA on high-affinity binding of benzodiazepines to brain membranes was investigated. GABA stimulated [3H]diazepam binding by more than 100% when extensively washed membranes from rat brain tissue were used. This GABA-stimulated benzodiazepine binding occurred in all brain regions examined. The stimulation was specific for GABA agonists. It was inhibited by the GABA receptor blocker bicuculline methiodide. A large number of compounds structurally closely related to GABA but without direct effect on the GABA receptor failed to enhance [3H]diazepam binding. The stimulation of benzodiazepine binding was caused by an increase in affinity; the number of binding sites remained unchanged. Half-maximal activation of [3H]diazepam binding occurred in the presence of 300 nM muscimol or 900 nM GABA. .beta.-Guanidinopropionic acid and imidazoleacetic acid were much weaker activators. The described stimulation of benzodiazepine high-affinity binding may be mediated by a receptor for GABA. This site of GABA action exhibits different properties when compared to GABA receptors, as characterized by high affinity binding of GABA agonists.This publication has 14 references indexed in Scilit:
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