Inhibition of the α9α10 nicotinic cholinergic receptor by neramexane, an open channel blocker of N-methyl-d-aspartate receptors

In this study we report the effects of neramexane, a novel amino-alkyl-cyclohexane derivative that is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, on recombinant rat α9α10 nicotinic acetylcholine receptors expressed in Xenopus laevis oocytes. We compared its effects with those...

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Detalles Bibliográficos
Autores: Plazas, Paola Viviana, Savino, Jessica, Kracun, Sebastian, Gomez Casati, Maria Eugenia, Katz, Eleonora, Parsons, Christopher G., Millar, Neil S., Elgoyhen, Ana Belen
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/79674
Acceso en línea:http://hdl.handle.net/11336/79674
Access Level:acceso abierto
Palabra clave:Acetylcholine
Hair Cells
N-Methyl-D-Aspartate Receptor Antagonist
Neramexane
Nicotinic Acetylcholine Receptors
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:In this study we report the effects of neramexane, a novel amino-alkyl-cyclohexane derivative that is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, on recombinant rat α9α10 nicotinic acetylcholine receptors expressed in Xenopus laevis oocytes. We compared its effects with those of memantine, a well-studied pore blocker of NMDA receptors, currently used in therapeutics for the treatment of Alzheimer's disease. Our results indicate that both compounds block acetylcholine-evoked responses at micromolar concentrations with a rank order of potency of neramexane > memantine, P < 0.05. Block by neramexane of acetylcholine responses was not overcome at high concentrations of the agonist, indicative of a non-competitive inhibition. The lack of interaction of neramexane with the ligand binding domain was confirmed by radioligand binding experiments in transfected tsA201 cells. Moreover, block did not involve an increase in desensitization kinetics, it was independent of the resting potential of the membrane at low concentrations of neramexane and slightly voltage-dependent at concentrations higher than 1 μM. Finally, clinically-relevant concentrations of neramexane blocked native α9α10-containing nicotinic acetylcholine receptors of rat inner hair cells, thus demonstrating a possible in vivo relevance in potentially unexplored therapeutic areas.