Inhibition of human α7 nicotinic acetylcholine receptors by open channel blockers of N-methyl-D-aspartate receptors

Maskell, P. D. , Speder, P., Newberry, N. R. and Bermudez, I. (2003) Inhibition of human α7 nicotinic acetylcholine receptors by open channel blockers of N-methyl-D-aspartate receptors. British Journal of Pharmacology, 140(7), pp. 1313-1319. (doi: 10.1038/sj.bjp.0705559) (PMID:14645141) (PMCID:PMC1574144)

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Abstract

Human α7 nicotinic acetylcholine (ACh) receptors were expressed in Xenopus oocytes and the effects of the N‐methyl‐D‐aspartate (NMDA) receptor open channel blockers memantine and cerestat on this receptor were examined using two‐electrode voltage‐clamp recordings and 125I‐α‐bungarotoxin (125I‐α‐bgtx) binding. Memantine and cerestat produced complete inhibition of ACh‐induced inward currents with affinities similar to that reported for native NMDA receptors. Cerestat, IC50 1.7 (−1; +2) μM, was more potent than memantine, IC50 5 (−3;+8) μM, and the effects of both drugs were fully and rapidly reversible. Inhibition of α7 receptor function was voltage‐independent, and it occurred at concentrations far lower than those needed to inhibit (never completely) binding of 125I‐α‐bgtx to α7 receptors, suggesting that the effects of memantine or cerestat are noncompetitive. These results provide evidence that human α7 receptors are inhibited by memantine and cerestat and suggest that caution should be applied when using these compounds to study systems in which NMDA and nACh receptors co‐exist.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Maskell, Peter
Authors: Maskell, P. D., Speder, P., Newberry, N. R., and Bermudez, I.
College/School:College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Journal Name:British Journal of Pharmacology
Publisher:Wiley
ISSN:0007-1188
ISSN (Online):1476-5381

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