兔近端小管曲部管腔膜囊泡中的钡离子敏感钾通道。

Ba2+-sensitive K+ channels in luminal-membrane vesicles from pars convoluta of rabbit proximal tubule.

作者信息

Jacobsen C, Røigaard-Petersen H, Sheikh M I

机构信息

Institute of Medical Biochemistry, University of Aarhus, Denmark.

出版信息

FEBS Lett. 1989 Jan 30;243(2):173-6. doi: 10.1016/0014-5793(89)80124-3.

DOI:10.1016/0014-5793(89)80124-3

PMID:2917644

Abstract

This paper describes properties of 86Rb+ fluxes through a novel K+ channel in luminal-membrane vesicles isolated from pars convoluta of rabbit proximal tubule. The uptake of 86Rb+ into potassium salt loaded vesicles was specifically inhibited by Ba2+. The isotope accumulation is driven by an electrical diffusion potential as shown in experiments using these membrane vesicles loaded with anions of different membrane permeability and was as follows: gluconate greater than SO4(2-) greater than Cl-. Furthermore, the vesicles containing the channels show a cation selectivity with the order K+ greater than Rb+ greater than Li+ greater than Na+ = choline+.

摘要

本文描述了86Rb+通过从兔近端小管曲部分离的管腔膜囊泡中一种新型钾通道的通量特性。86Rb+进入装载钾盐的囊泡的过程被Ba2+特异性抑制。同位素积累由电扩散电位驱动，如使用装载具有不同膜通透性阴离子的这些膜囊泡进行的实验所示，顺序如下：葡萄糖酸盐大于SO4(2-)大于Cl-。此外，含有该通道的囊泡表现出阳离子选择性，顺序为K+大于Rb+大于Li+大于Na+ = 胆碱+。