Activation of Background Membrane Conductance by the Tyrosine Kinase Inhibitor Tyrphostin A23 and Its Inactive Analog Tyrphostin A1 in Guinea Pig Ventricular Myocytes

The Japanese Journal of Pharmacology

Toshitsugu Ogura¹  Toshishige Shibamoto¹  Sunao Imanishi¹ 

[1] Second Department of Physiology, Kanazawa Medical University

关键词: Tyrphostin;    Tyrosine kinase;    Na+-Ca2+ exchange;   

DOI  :  10.1254/jjp.87.235

学科分类：药理学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(15)The effects of the tyrosine kinase (TK) inhibitor tyrphostin A23 and its inactive analog tyrphostin A1 on background membrane conductance were investigated in guinea pig ventricular myocytes. TK-inhibiting A23 reversibly increased membrane conductance under conditions designed to minimize Na+, Ca2+, K+, and Na+-K+ pump currents. Similar stimulatory action was obtained with TK-inactive A1. The tyrphostin-induced current was inhibited by omitting external Na+ or Ca2+, suppressed by chelating internal Ca2+, blocked by external Cd2+ and Ni2+, and insensitive to changes in internal Cl− concentration. We conclude that tyrphostins have a direct, TK-independent action that increases membrane conductance probably by stimulating Na+-Ca 2+ exchange.

【 授权许可】

Unknown