Activation of single Ca2+‐dependent K+ channel by external ATP in mouse macrophages
Open Access
- 16 July 1990
- journal article
- Published by Wiley in FEBS Letters
- Vol. 267 (2) , 281-284
- https://doi.org/10.1016/0014-5793(90)80945-f
Abstract
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).Keywords
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