胚胎期鸡破骨细胞中的河豚毒素敏感性快速钠电流

Tetrodotoxin-sensitive fast Na+ current in embryonic chicken osteoclasts.

作者信息

Gáspár R, Weidema A F, Krasznai Z, Nijweide P J, Ypey D L

机构信息

Biophysics Department, University Medical School, Debrecen, Hungary.

出版信息

Pflugers Arch. 1995 Aug;430(4):596-8. doi: 10.1007/BF00373899.

DOI:10.1007/BF00373899

PMID:7491289

Abstract

A voltage-dependent, fast, transient inward current was characterized in embryonic chicken osteoclasts using the permeabilized patch configuration of the patch-clamp technique. The current was activated by depolarizations to higher than -28 +/- 4 mV from a holding potential of -80 mV. It peaked within 1-1.5 ms, and inactivated within 3.3-6.9 ms. The 50% inactivation voltage was -59 +/- 6 mV with a steepness factor of 0.11 +/- 0.06. The current disappeared with the removal of extracellular Na+ and was reversibly blocked by tetrodotoxin (K0.5 < 15 nM) but not by verapamil (< or = 100 microM). We conclude that this new current in embryonic chicken osteoclasts is a sodium current known from excitable cells.

摘要

利用膜片钳技术的透化膜片配置，在胚胎期鸡破骨细胞中鉴定出一种电压依赖性、快速、瞬时内向电流。该电流通过从-80 mV的钳制电位去极化至高于-28±4 mV而激活。它在1-1.5毫秒内达到峰值，并在3.3-6.9毫秒内失活。50%失活电压为-59±6 mV，陡度因子为0.11±0.06。去除细胞外Na+后电流消失，且可被河豚毒素（K0.5<15 nM）可逆性阻断，但不受维拉帕米（≤100 μM）阻断。我们得出结论，胚胎期鸡破骨细胞中的这种新电流是一种可兴奋细胞中已知的钠电流。