title: Functional in vitro characterization of CR 3394: a novel voltage dependent N-methyl-D-aspartate (NMDA) receptor antagonist.
abstract: Using the patch-clamp technique, we studied the effect of two novel adamantane derivatives, N-[2-(3,5-dimethyl-1-adamantyl)ethyl] guanidine (CR 3391) and N-[2-(3,5-dimethyl-1-adamantyl) ethyl]acetamidine (CR 3394), on NMDA receptors expressed in cortical neuron cultures. Our data show that CR 3391 and CR 3394 reduce NMDA-evoked currents (IC50 = 1.7 +/- 0.6 microM and 6.7 +/- 1.5 microM, respectively). This antagonism is non-competitive and is completely reversible. The effect of CR 3394, like that of memantine, was strongly voltage dependent. HEK293 cells expressing NR1a/NR2B recombinant NMDA receptors and immature neurons (DIV 8-9) were more sensitive to CR 3394 antagonism than NR1a/NR2A expressing cells and DIV 15 neurons. CR 3394 also reduced the duration and amplitude of miniature excitatory post-synaptic currents mediated exclusively by NMDA receptors (NMDA-mEPSCs). Both memantine and CR 3394 inhibited NMDA-evoked [3H]norepinephrine release from rat hippocampal slices in a concentration-dependent manner with similar potency. CR 3394, but not memantine, increased cathecholamine resting release at low micromolar concentrations. Moreover, in an in vitro model of neurotoxicity, CR 3394 strongly reduced glutamate- and NMDA-induced neuronal death. Taken together, our data highlight pharmacological features of CR 3394 in vitro that prompt us to further evaluate it as a candidate for the treatment of neurodegenerative disorders.
authors.affiliation: Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Losi
authors.forename: Marco
authors.initials: M
authors.lastname: Lanza
authors.forename: Francesco
authors.initials: F
authors.lastname: Makovec
authors.forename: Roberto
authors.initials: R
authors.lastname: Artusi
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Caselli
authors.forename: Giulia
authors.initials: G
authors.lastname: Puia
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000494:pharmacology; D000578:Amidines / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D016202:N-Methylaspartate / Q000494:pharmacology; D009433:Neural Inhibition / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D009638:Norepinephrine / Q000378:metabolism; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D014162:Transfection / Q000379:methods; D014316:Tritium / Q000378:metabolism
chemical_list: D000578:Amidines; D018691:Excitatory Amino Acid Antagonists; C510385:N-(2-(3,5-dimethyl-1-adamantyl)ethyl)acetamidine; C473649:NR1A NMDA receptor, rat; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D014316:Tritium; D016202:N-Methylaspartate; D000218:Adamantane; D004298:Dopamine; D009638:Norepinephrine