谷氨酸对人交感神经母细胞瘤SH-SY5Y细胞系超极化激活的阳离子通道的影响

摘要

目的 观察谷氨酸(Glu)对交感神经细胞超极化激活的阳离子通道(Ih 通道)活动的影响. 方法 采用人交感神经母细胞瘤SH-SY5Y细胞系作为交感神经细胞模型,用全细胞电压箝方式记录Ih 通道电流. 结果 SH-SY5Y细胞存在Ih通道电流;Glu(1mmol/L)可抑制SH-SY5Y细胞Ih 电流的K+电流成分,但增强Ih 电流的Ca2+电流和Na+电流成分,综合效应是使Ih电流增大. 结论 Glu可增大SH-SY5Y细胞的Ih 电流. 这一效应提示,Glu可能通过诱发交感神经元去极化并促进其传出冲动增加.%Objective To investigate the effect of glutamate on the hyperpolarization -activated cation channels ( Ih channel ) in sympathetic neurons.Methods Using the human sympathetic neuroblastoma cell line SH -SY5Y as a model of sympathetic neurons , we recorded the Ih channel currents with the whole -cell voltage clamp technique.Results There were Ih currents in the SH-SY5Y cells. Glu (1mmol/L) suppressed the K +component of Ih currents, but enhanced the Ca2+and Na+components of Ih currents, and as a whole, increased the Ih currents.Conclusion Glu increases the Ih currents of SH-SY5Y cells.This result suggests that Glu may induce depo-larization and efferent impulses of sympathetic neurons .