Calcium channel antagonists induce direct inhibition of the outward rectifying potassium channel in tobacco protoplasts

FEBS Letters

Guern, Jean¹  Barbier-Brygoo, Hélène¹  Zimmermann, Sabine¹  Van Duijn, Bert²  Thomine, Sébastien¹ 

[1] Institut des Sciences Végétales, CNRS, F-91198 Gif-sur-Yvette Cedex, France;Institute of Molecular Plant Sciences, Clusius Laboratory, 2333 AL Leiden and Department of Physiology, Leiden University, 2300 RC Leiden, The Netherlands

关键词: Patch clamp;    Potassium outward rectifier;    Verapamil;    Nifedipine;    Bepridil;    Tobacco protoplast;    E x;    equilibrium potential for ion X;    IC50;    concentration inducing 50% inhibition;    pS;    picosiemens;    V m;    applied membrane potential;    BAPTA;    1;    2-bis (2-aminophenoxy) ethane-N;    N;    N';    N'-tetra acetic acid;    EGTA;    ethylene glycol bis (2-aminoethylether)-N;    N;    N';    N'-tetracetic acid;    MES;    2-(N-morpholino) ethanesulfonic acid;    Tris;    Tris (hydroxymethyl) aminomethane;   

DOI  :  10.1016/0014-5793(94)80170-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Verapamil, nifedipine and bepridil, three antagonists of L-type calcium channels in animal cells, were shown to induce direct inhibition of outward rectifying potassium current in Nicotiana tabacumcv. Xanthi protoplasts with IC₅₀ of 5 μM, 5 μM and 1 μM, respectively. In the outside-out configuration, verapamil reduced the open probability of the ion channel responsible for the outward rectifying potassium conductance. Verapamil also blocked the outward rectifying potassium conductance in protoplasts from the N. tabacum cv. Bright Yellow cell line. Thus, studies using these molecules to demonstrate the involvement of calcium channels in plant physiological responses should be regarded with caution.

【 授权许可】

Unknown