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Activation of single Ca 2+ ‐dependent K + channel by external ATP in mouse macrophages
Author(s) -
Hara N.,
Ichinose M.,
Sawada M.,
Imai K.,
Maeno T.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80945-f
Subject(s) - chemistry , microbiology and biotechnology , physics , biophysics , biology
Single Ca 2+ ‐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 Ca 2+ or treatment with an intracellular Ca 2+ 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).