Article date: 1990/4/25
PubMed ID: 2163855
Journal name: European journal of pharmacology (ISSN: 0014-2999)
[3H]t-Butylbicycloorthobenzoate ([3H]TBOB) binds to specific sites on crude synaptic rat brain membranes. The dissociation constant, Kd, determined from saturation experiments is near 8 nM and the receptor density Bmax is about 20 pmol/g wet tissue. Non-specific binding constitutes about 35% of the total binding at 4 nM [3H]TBOB. The association of [3H]TBOB is monophasic but its dissociation is biphasic. Kd values of 8 nM (70% of the binding sites) and 20 nM (30% of the binding sites) were estimated from the kinetic data. These values differ from those previously reported. Specifically bound [3H]TBOB is displaced by picrotoxin and by t-butylbicyclophosphorothionate (TBPS). No simple competitive interaction of picrotoxin with [3H]TBOB binding was found. Micromolar quantities of the GABAergic facilitating compounds, GABA, muscimol and diazepam inhibited [3H]TBOB binding in an allosteric manner.
Author List: Van Rijn C M, Willems-van Bree E, Van der Velden T J, Rodrigues de Miranda J F
Publication Types: Journal Article
Substances mentioned in the article: Bridged Bicyclo Compounds; Bridged Bicyclo Compounds, Heterocyclic; Bridged-Ring Compounds; Receptors, GABA-A; Picrotoxin; tert-butylbicyclo-2-benzoate;
Mesh terms: Animals; Binding, Competitive; Bridged Bicyclo Compounds/metabolism; Bridged Bicyclo Compounds, Heterocyclic; Bridged-Ring Compounds/metabolism; In Vitro Techniques; Kinetics; Male; Membranes/metabolism; Picrotoxin/metabolism; Rats; Rats, Inbred Strains; Receptors, GABA-A/metabolism; Synapses/metabolism;