海葵毒素Anthopleurin-Q对豚鼠心室肌细胞钠电流的影响。

Effect of sea anemone toxin anthopleurin-Q on sodium current in guinea pig ventricular myocytes.

作者信息

Fu L Y, Li Y, Cheng L, Zhou H Y, Yao W X, Xia G J, Jiang M X

机构信息

Department of Pharmacology, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.

出版信息

Acta Pharmacol Sin. 2001 Dec;22(12):1107-12.

PMID:11749809

Abstract

AIM

To investigate the effects of a sea anemone toxin anthopleurin-Q (AP-Q) isolated from Anthopleura xanthogrammica on sodium current (INa) in isolated guinea pig ventricular myocytes.

METHODS

Single myocytes were dissociated by enzymatic dissociation method. INa was recorded using whole-cell patch-clamp technique.

RESULTS

AP-Q (3 - 300 nmol/L) increased INa in a concentration-dependent manner. The EC50 value for increasing INa was 104 nmol/L (95 % confidence range: 78 - 130 nmol/L). AP-Q 300 nmol/L shifted the I-V curve to the leftward, changed the membrane potential of half maximal activation to more negative potential from (-36.3 +/- 2.3) mV to (-43 +/- 3) mV (n = 6, P < 0.01) and changed the membrane potential of half maximal inactivation to more positive potential from (-75 +/- 6) mV to (-59 +/- 5) mV (n = 6, P < 0.01). AP-Q 300 nmol/L shortened the half-recovery time of INa from (114 +/- 36) ms to (17 +/- 2) ms (n = 6, P < 0.01). The fast inactivation time constant (tauf) of INa was markedly increased by AP-Q 300 nmol/L.

CONCLUSION

AP-Q has a stimulating effect on I(Na) with slowing the inactivation course of INa.

摘要

目的

研究从黄斑海葵中分离出的海葵毒素 Anthopleurin-Q（AP-Q）对豚鼠离体心室肌细胞钠电流（INa）的影响。

方法

采用酶解法分离单个心肌细胞。运用全细胞膜片钳技术记录 INa。

结果

AP-Q（3 - 300 nmol/L）以浓度依赖性方式增加 INa。增加 INa 的 EC50 值为 104 nmol/L（95%置信区间：78 - 130 nmol/L）。300 nmol/L 的 AP-Q 使 I-V 曲线向左移位，将半数最大激活膜电位从（-36.3±2.3）mV 变为更负的电位（-43±3）mV（n = 6，P < 0.01），并将半数最大失活膜电位从（-75±6）mV 变为更正的电位（-59±5）mV（n = 6，P < 0.01）。300 nmol/L 的 AP-Q 将 INa 的半数恢复时间从（114±36）ms 缩短至（17±2）ms（n = 6，P < 0.01）。300 nmol/L 的 AP-Q 显著增加了 INa 的快速失活时间常数（tauf）。