The activity of zolpidem and other hypnotics within the gamma-aminobutyric acid (GABAA) receptor supramolecular complex, as determined by 35S-t-butylbicyclophosphorothionate (35S-TBPS) binding to rat cerebral cortex membranes. 1990

G K Lloyd, and G Danielou, and F Thuret
Synthelabo Recherche (L.E.R.S.), Bagneux, France.

The present study compares the effects of different hypnotics acting at omega 1/omega 2 sites (zolpidem, zopiclone, flunitrazepam and triazolam) on 35S-t-butylbicyclophosphorothionate (35S-TBPS) binding to well-washed rat cerebral membranes, in the presence of 1M NaCl. Under these conditions, all compounds enhanced 35S-TBPS binding in the 0.05 to 10 microM range with EC50 values and maximal enhancement of: zolpidem, 84 nM and 36%; flunitrazepam, 8 nM and 41%; zopiclone, 171 nM and 51%; triazolam, 2 nM and 42%. Under these conditions, gamma-aminobutyric acid enhanced 35S-TBPS binding with an EC50 of 240 nM and a 38% maximal increase. The EC50 values for the stimulation of 35S-TBPS binding are well correlated, with (r = 0.97) the affinity of these compounds at omega 1/omega 2 sites, and are in the same concentration range. This enhanced binding was due to an altered apparent affinity for the 35S-TBPS recognition site without any change in the number of sites (Scatchard analysis). The effect of zolpidem and other hypnotics was antagonized by flumazenil. This was an apparently competitive antagonism in the case of zolpidem or flunitrazepam, whereas for zopiclone, increasing the concentration of the hypnotic did not overcome the antagonism. Bicuculline only partially antagonized the hypnotic-induced enhancement of 35S-TBPS binding. This antagonism was more effective for zopiclone (-57%) than for either zolpidem (-33%) or flunitrazepam (-30%). Zolpidem and the other hypnotics studied induced a fast component of dissociation which was not observed in the control membranes. These findings are consistent with the hypothesis that omega 1/omega 2 agonists increase the frequency of openings of the chloride ionophore, with both gamma-aminobutyric acid-A receptor-dependent and -independent mechanisms.

UI MeSH Term Description Entries
D006993 Hypnotics and Sedatives Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety. Hypnotic,Sedative,Sedative and Hypnotic,Sedatives,Hypnotic Effect,Hypnotic Effects,Hypnotics,Sedative Effect,Sedative Effects,Sedatives and Hypnotics,Effect, Hypnotic,Effect, Sedative,Effects, Hypnotic,Effects, Sedative,Hypnotic and Sedative
D008297 Male Males
D011725 Pyridines Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
D011919 Rats, Inbred Strains Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding. August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011963 Receptors, GABA-A Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and contain an integral membrane chloride channel. Each receptor is assembled as a pentamer from a pool of at least 19 different possible subunits. The receptors belong to a superfamily that share a common CYSTEINE loop. Benzodiazepine-Gaba Receptors,GABA-A Receptors,Receptors, Benzodiazepine,Receptors, Benzodiazepine-GABA,Receptors, Diazepam,Receptors, GABA-Benzodiazepine,Receptors, Muscimol,Benzodiazepine Receptor,Benzodiazepine Receptors,Benzodiazepine-GABA Receptor,Diazepam Receptor,Diazepam Receptors,GABA(A) Receptor,GABA-A Receptor,GABA-A Receptor alpha Subunit,GABA-A Receptor beta Subunit,GABA-A Receptor delta Subunit,GABA-A Receptor epsilon Subunit,GABA-A Receptor gamma Subunit,GABA-A Receptor rho Subunit,GABA-Benzodiazepine Receptor,GABA-Benzodiazepine Receptors,Muscimol Receptor,Muscimol Receptors,delta Subunit, GABA-A Receptor,epsilon Subunit, GABA-A Receptor,gamma-Aminobutyric Acid Subtype A Receptors,Benzodiazepine GABA Receptor,Benzodiazepine Gaba Receptors,GABA A Receptor,GABA A Receptor alpha Subunit,GABA A Receptor beta Subunit,GABA A Receptor delta Subunit,GABA A Receptor epsilon Subunit,GABA A Receptor gamma Subunit,GABA A Receptor rho Subunit,GABA A Receptors,GABA Benzodiazepine Receptor,GABA Benzodiazepine Receptors,Receptor, Benzodiazepine,Receptor, Benzodiazepine-GABA,Receptor, Diazepam,Receptor, GABA-A,Receptor, GABA-Benzodiazepine,Receptor, Muscimol,Receptors, Benzodiazepine GABA,Receptors, GABA A,Receptors, GABA Benzodiazepine,delta Subunit, GABA A Receptor,epsilon Subunit, GABA A Receptor,gamma Aminobutyric Acid Subtype A Receptors
D002540 Cerebral Cortex The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions. Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D005442 Flumazenil A potent benzodiazepine receptor antagonist. Since it reverses the sedative and other actions of benzodiazepines, it has been suggested as an antidote to benzodiazepine overdoses. Flumazepil,Anexate,Lanexat,Ro 15-1788,Romazicon,Ro 15 1788,Ro 151788
D005445 Flunitrazepam A benzodiazepine with pharmacologic actions similar to those of DIAZEPAM that can cause ANTEROGRADE AMNESIA. Some reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. The United States Government has banned the importation of this drug. Fluridrazepam,Rohypnol,Fluni 1A Pharma,Flunibeta,Flunimerck,Fluninoc,Flunitrazepam-Neuraxpharm,Flunitrazepam-Ratiopharm,Flunitrazepam-Teva,Flunizep Von Ct,Narcozep,RO-5-4200,Rohipnol,Flunitrazepam Neuraxpharm,Flunitrazepam Ratiopharm,Flunitrazepam Teva,RO54200,Von Ct, Flunizep
D005680 gamma-Aminobutyric Acid The most common inhibitory neurotransmitter in the central nervous system. 4-Aminobutyric Acid,GABA,4-Aminobutanoic Acid,Aminalon,Aminalone,Gammalon,Lithium GABA,gamma-Aminobutyric Acid, Calcium Salt (2:1),gamma-Aminobutyric Acid, Hydrochloride,gamma-Aminobutyric Acid, Monolithium Salt,gamma-Aminobutyric Acid, Monosodium Salt,gamma-Aminobutyric Acid, Zinc Salt (2:1),4 Aminobutanoic Acid,4 Aminobutyric Acid,Acid, Hydrochloride gamma-Aminobutyric,GABA, Lithium,Hydrochloride gamma-Aminobutyric Acid,gamma Aminobutyric Acid,gamma Aminobutyric Acid, Hydrochloride,gamma Aminobutyric Acid, Monolithium Salt,gamma Aminobutyric Acid, Monosodium Salt
D000077334 Zolpidem An imidazopyridine derivative and short-acting GABA-A receptor agonist that is used for the treatment of INSOMNIA. Imidazo(1,2-a)pyridine-3-acetamide, N,N,6-trimethyl-2-(4-methylphenyl)-,Ambien,Amsic,Bikalm,Dalparan,N,N,6-Trimethyl-2-(4-methylphenyl)imidazo(1,2a)pyridine-3-acetamide hemitartrate,SL 80.0750,SL-800750-23-N,Stilnoct,Stilnox,Zodormdura,Zoldem,Zolirin,Zolpi-Lich,Zolpidem 1A Pharma,Zolpidem AbZ,Zolpidem Hemitartrate,Zolpidem Tartrate,Zolpimist,Zolpinox,SL 800750 23 N,Zolpi Lich

Related Publications

G K Lloyd, and G Danielou, and F Thuret
August 1995, Pharmacology & toxicology,
G K Lloyd, and G Danielou, and F Thuret
May 1984, The Journal of neuroscience : the official journal of the Society for Neuroscience,
G K Lloyd, and G Danielou, and F Thuret
April 2007, British journal of pharmacology,
G K Lloyd, and G Danielou, and F Thuret
September 1985, The Journal of neuroscience : the official journal of the Society for Neuroscience,
Copied contents to your clipboard!