渗透压刺激对TRGN钠离子通道电流的影响.docVIP

 n 渗透压刺激对 TRGN 钠离子通道电流的 影响# 沈颉飞，王海业，杜莉* 5 10 15 20 25 30 35 （四川大学华西口腔医学院，口腔疾病研究国家重点实验室，成都 610041） 摘要：目的 探讨细胞内液渗透压对三叉神经节神经元(TRGN)上的电压门控钠离子通道 (VGSCs)的生物力学影响。方法 TRGN 细胞从 Sprague–Dawley (SD)乳鼠分离出来之后，运 用膜片钳全细胞记录的方法对 VGSCs 电流进行记录和分析，通过调节电极内液的组成成分来 控制细胞内液渗透压；再与正常渗透压相对比探讨低渗(260mOsm)和高渗(350mOsm) 对通道 激活和失活动力学的影响。结果 与对照组相比较，细胞内液低渗刺激可以影响 VGSCs 电流 的激活和失活特性，包括 V0.5 、激活曲线(G-V 曲线)特征均有明显的统计学意义(P0.05)； 然而对于细胞内高渗刺激，仅 VGSCs 电流的失活特性有一定改变，包括失活比例和斜率 k 值。结论 三叉神经节神经元上电压门控钠离子通道的动力学参数可以通过细胞内液低渗和 高渗进行调节，并可表现为不同特征。 关键词：三叉神经节神经元；渗透压浓度；电压门控钠离子通道；电生理特性；全细胞膜片 钳技术 中图分类号：R783.9 Effects of intracellular osmolality changes on the voltage-gated sodium channel currents of trigeminal ganglion neurons SHEN Jiefei, WANG Haiye, DU Li (State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, ChengDu 610041) Abstract: Objection: To evaluate biomechanical effects of intracellular changes on the voltage-gated sodium channels (VGSCs) on trigeminal ganglion neurons (TRGN). Methods and Materials: TRGN cells were acutely isolated from the neonatal Sprague–Dawley rats. The voltage-dependent currents of the VGSCs on these neurons were elicited and analyzed by whole-cell patch-clamp recordings and the intracellular anisotonicity stimuli was established by adjusting the content of pipette solution. We evaluated the effects of hypo- (260mOsm) and hypertonic (350mOsm) osmolarity on the activation and inactivation kinetics of VGSCs on TRGN, compared with the normal intracellular environment. Results: The results demonstrated that intracellular hypotonic stimuli could influence both the activation and inactivation characteristics of VGSCs currents, including the membrane potential at half inactivation (V0.5) of the G-V and inactivation curves has obvious statistics significance (P0.05) between hypotonicity (260mOsm) and isotonicity (306mOsm). However, only inactivation properties changed under intracellular hypertonic effects, including inactivation rate and k value. Conclusion: It