The potent 5-HT3 receptor antagonist (R)-zacopride labels an additional high affinity site in the central nervous system.
The binding characteristics of [3H](R)- and [3H](S)-zacopride were investigated in membranes from the rat entorhinal cortex and NG 108-15 clonal cells. In contrast to [3H](S)-zacopride which bound solely to 5-HT3 receptors, [3H](R)-zacopride recognized another class of binding sites, called the (R)-sites, in both membrane preparations. In addition to (R)-zacopride (Ki = 3-11 nM), only (R)-iodo-zacopride, (R)-dechloro-zacopride, prazosin and mianserin exhibited high to moderate affinity for the (R)-sites, whose possible functions remain to be established.
Kidd
E
E
INSERM U288, Neurobiologie Cellulaire et Fonctionnelle, Faculté de Médecine Pitié-Salpêtrière, Paris, France.
Bouchelet de Vendegies
I
I
Levy
J C
JC
Hamon
M
M
Gozlan
H
H
D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002462:Cell Membrane / Q000378:metabolism; D002999:Clone Cells; D066298:In Vitro Techniques; D051381:Rats; D012702:Serotonin Antagonists; D014316:Tritium
D001549:Benzamides; D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D012702:Serotonin Antagonists; D014316:Tritium; C055971:zacopride