Losi Gabriele, Lanza Marco, Makovec Francesco, Artusi Roberto, Caselli Gianfranco, Puia Giulia
Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, via Campi 183, 41100 Modena, Italy.
Neuropharmacology. 2006 Mar;50(3):277-85. doi: 10.1016/j.neuropharm.2005.09.002. Epub 2005 Oct 19.
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.
我们运用膜片钳技术，研究了两种新型金刚烷衍生物，即N-[2-(3,5-二甲基-1-金刚烷基)乙基]胍（CR 3391）和N-[2-(3,5-二甲基-1-金刚烷基)乙基]乙脒（CR 3394）对皮质神经元培养物中表达的NMDA受体的影响。我们的数据表明，CR 3391和CR 3394可降低NMDA诱发的电流（IC50分别为1.7±0.6微摩尔和6.7±1.5微摩尔）。这种拮抗作用是非竞争性的，且完全可逆。CR 3394的作用与美金刚类似，强烈依赖电压。与表达NR1a/NR2A的细胞和第15天的神经元相比，表达NR1a/NR2B重组NMDA受体的HEK293细胞和未成熟神经元（第8 - 9天）对CR 3394的拮抗作用更敏感。CR 3394还缩短了仅由NMDA受体介导的微小兴奋性突触后电流（NMDA-mEPSCs）的持续时间并降低了其幅度。美金刚和CR 3394均以浓度依赖性方式抑制NMDA诱发的大鼠海马切片中[3H]去甲肾上腺素的释放，效力相似。在低微摩尔浓度下，CR 3394而非美金刚增加了儿茶酚胺的基础释放。此外，在神经毒性的体外模型中，CR 3394强烈减少了谷氨酸和NMDA诱导的神经元死亡。综上所述，我们的数据突出了CR 3394在体外的药理学特性，促使我们进一步评估其作为神经退行性疾病治疗候选药物的潜力。
