Activation of single Ca2+‐dependent K+ channel by external ATP in mouse macrophages

FEBS Letters

Maeno, T.²  Ichinose, M.²  Hara, N.³  Imai, K.¹  Sawada, M.² 

[1] Department of Biochemistry, Shimane Medical University, Izumo 693, Japan;Department of Physiology, Shimane Medical University, Izumo 693, Japan;Central Research Laboratories, Shimane Medical University, Izumo 693, Japan

关键词: External ATP;    Ca2+-dependent K+ conductance;    Single channel;    Patch-clamp;    Mouse peritoneal macrophage;   

DOI  :  10.1016/0014-5793(90)80945-F

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Single Ca²⁺-dependent K⁺ currents responding to external ATP were recorded from cell-attached patches on mouse peritoneal macrophages. Extracellularly applied ATP activated an inward single-channel current with a conductance of 25 pS and a reversal potential of −79 mV (pipette potential, V _p) when the pipette contained a 145 mM KC1 solution. The reversal potential was shifted 56 mV positive by a 10-fold reduction in external (pipette) K⁺ concentration. The effect of ATP was abolished by either removal of external Ca²⁺ or treatment with an intracellular Ca²⁺ chelator, the acetoxymethyl ester of 1,2-bis (2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM). This channel has a mean open time of 9.1 ms and open probability was not strongly dependent on V _p in the range tested (+ 120 to −30 mV).

【 授权许可】

Unknown