人胰淀素和烟碱诱导相同离子通道的激活*
Same ion channel activation induced by human amylin and nicotine

目的:观察人胰淀素和烟碱对大鼠脑乙酰胆碱能神经元膜上受体通道活动的影响。方法:在急性分离的大鼠基底前脑神经元上,采用细胞贴附式和全细胞膜片钳技术进行检测。结果:人胰淀素或烟碱单独应用可以分别诱导相同通道的激活。烟碱与人胰淀素诱导的37 pS电导单通道电流幅度分别为(-3.6±0.4)和(-3.5±0.3)pA,65 pS电导单通道电流幅度分别为(-6.0±0.2)和(-6.1±0.3)pA,两电导水平的单通道电流比较,差异均无统计学意义(P均>0.05)。在电流钳记录模式,人胰淀素或烟碱单独应用可引起神经元膜电位去极化并诱发动作电位的产生。DHβE完全阻断烟碱和人胰淀素的作用,应用人胰淀素受体拮抗剂AC253也观察到类似的效果。结论:人胰淀素受体和烟碱受体在中枢神经元存在功能性协同作用。
Aim: To observe the channel activities of two receptors excited by human amylin and nicotine on rat brain acetylcholine neurons.Methods: The single channel cell-attached recordings and whole cell patch-clamp recordings were performed on acutely dissociated neurons of rat basal forebrain nucleus.Results: Either human amylin or nicotine individually caused the activation of the same channel. The smaller conductance(37 pS)single-channel current amplitudes induced by nicotine and amylin were(-3.6±0.4)and(-3.5±0.3)pA, respectively; the large conductance(65 pS)single-channel current amplitudes induced by them were(-6.0±0.2)and(-6.1±0.3)pA, respectively(P>0.05). Nicotine and amylin evoked the membrane depolarization and repeating action potential of neurons under current-clamp recording conditions. DHβE blocked the effects of nicotine and amylin. The similar effect was observed by using AC253.Conclusion: Human amylin and nicotine receptors functionally cooperate in the central neurons