【摘要】 采用全细胞膜片钳技术观察大鼠三叉神经节神经元5-羟色胺激活电流(I5-HT)及其特征。在大多数受检细胞(64／87,73.6％)特别是中、小型细胞,外加5-HT可引起一快去敏感的内向电流,此内向电流可被5-HT3受体特异性激动剂2-甲基-5-羟色胺所模拟,被5-HT3受体拮抗剂ICS 250-930可逆性阻断。I5-HT浓度-反应曲线的阈浓度为3×10-7mol／L,饱和浓度约为3×10-3mol／L,EC50为21.4+2.2μmol／L,Hill系数为0.96。I5-HT的翻转电位在-2.5 mV左右。胞内透析GDP-β-S证明I5-HT不依赖于G蛋白而存在。本研究结果为了解5-HT3受体介导电流及其特征提供了有关的资料。更多还原

【Abstract】 Patch-clamp technique was used to study the characteristics of 5-hydroxytryptamine (5-HT )-activated current(I5-HT) in rat trigeminal ganglion neurons. 5-HT applied extracellularly induced an inward current with rapid desensitization in most neurons tested (64/87, 73. 6%) , especially in small- and medium-sized neurons. This I5-HT could be mimicked by 2-methyl-5-HT, an agonist of 5-HT3 receptor, and blocked by ICS 250-930, an antagonist of 5-HT3 receptor. The threshold concentration and saturation concentration of 5-HT for the concentration-response curve of I5-HT was measured to be 3 × 10-7 mol/L and 3 × 10-3 mol/L respectively! and the EC50 was 21. 4±2. 2 μmol/L with the apparent Hill coefficient being 0. 96. The reversal potential for I5-HT was at -2. 5 mV. Intracellular dialysis of GDP-β-S revealed that I5-HT was independent of G-protein. These results may provide a basis for understanding 5-HT3 receptor-mediated current and its characteristics.更多还原