title: Benzodiazepine receptor modulation of [35S]TBPS binding to the chloride channel. Noncompetitive inhibition of classical benzodiazepines and competitive inhibition of the partial agonist, CGS 9895, by CGS 8216.
abstract: Benzodiazepine receptor ligands are known to modulate the binding of [35S]TBPS to the chloride channel via an allosteric action. In the cases of diazepam, zopiclone and CGS 9895, the enhanced binding of [35S]TBPS induced by these benzodiazepine agonists was antagonized by CGS 8216. This antagonism was characterized both by a shift to the right and a decrease in the maximal stimulation, for the dose-response curves of diazepam and zopiclone. In the case of CGS 9895, the maximal response was not decreased. These data indicate that CGS 8216 is a noncompetitive antagonist of classical benzodiazepine receptor agonists but is a competitive inhibitor of the partial agonist, CGS 9895.
mesh_terms: D000818:Animals; D001569:Benzodiazepines / Q000037:antagonists & inhibitors* / Q000502:physiology; D001643:Bridged Bicyclo Compounds / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism*; D011720:Pyrazoles / Q000494:pharmacology*; D051381:Rats; D011963:Receptors, GABA-A / Q000502:physiology*; D013462:Sulfur Radioisotopes
chemical_list: D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds; D002712:Chlorides; D007473:Ion Channels; D011720:Pyrazoles; D011963:Receptors, GABA-A; D013462:Sulfur Radioisotopes; D001569:Benzodiazepines; C037476:tert-butylbicyclophosphorothionate; C039232:2,5-dihydro-2-(4-methoxyphenyl)-3H-pyrazolo(4,3-c)quinolin-3-one; C033830:2-phenylpyrazolo(4,3-c)quinolin-3(5H)-one