Effects of Glutamic Acid on C-type Inactivation of Kv1.4ΔN Channel

作     者：叶琤 李晓艳 舒周伍 蒋学俊 

作者机构：Department of Cardiology Renmin HospitalWuhan University 

出 版 物：《South China Journal of Cardiology》 (岭南心血管病杂志（英文版）)

年 卷 期：2008年第9卷第1期

页      面：39-43页

学科分类：1001[医学-基础医学(可授医学、理学学位)] 10[医学] 

主　　题：glutamic acid Kv1.4ΔN C-type inactivation xenopus oocytes 

摘      要：Objectives Acidosis has an inhibitory effect on the inactivation of Kv1.4 ΔN channel through the position H508. So in order to show the effects of glutamic acid on the mutant Kv 1.4 channel that lacks N-type inactivation （Kv1.4 Δ2-146）, we studied in the expression system of the Xenopus oocytes. Methods The two-electrode voltage-clamp technique （TEV） was used to record the currents. Results Acidosis increased fKv1.4 Δ2-146 C-type inactivation. After application of glutamic acid （1 mmol/L） to Kv1.4 Δ2-146 increased C-type inactivation further, changed inactivation time constants from （2.02 ± 0.39 s ） to （1.71 ± 0.23 s） （P〈 0.05） at ＋50mv, and shifted the steady-state inactivation curves of Kv1.4 ΔN to positive potential, which was from （-44.30 ± 0.59 mV） to （-39.88 ± 0.29 mV）（P〈0.05）. and slowed the rate of recovery from inactivation, which was from （1.64 ± 0.19 s） to （1.91 ± 0.23 s）（P〈 0.05）. Conclusions Together, these results suggest that 1 mmol/L glutamic acid accelerates the C-type inactivation of Kv1.4 ΔN in pH 6.8.