Open AccessSK4 Encodes Intermediate Conductance Ca2+-Activated K+ Channels in Mouse Urinary Bladder Smooth Muscle Cells
Author(s) -
Susumu Ohya,
Shigeo Kimura,
Mika Kitsukawa,
Katsuhiko Muraki,
Minoru Watanabe,
Yuji Imaizumi
Publication year - 2000
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - Slovenian
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.84.97
Subject(s) - charybdotoxin , conductance , chemistry , iberiotoxin , biophysics , biochemistry , membrane potential , biology , physics , condensed matter physics
The single channel current of intermediate conductance Ca2 +-activated K+ channel (IK channel) was measured in mouse urinary bladder myocytes (MBM), and the molecular basis of the channel was suggested to be the SK4 subtype by RT-PCR. Among Ca2+-activated K+ channel subtypes (SK2, SK3, SK4 and BK), the mRNAs of SK4 and BK were predominantly expressed in MBM. IK channel currents recorded from MBM showed: 38.7 pS slope conductance under symmetrical 140 mM K+ conditions, Ca2+-dependent activation, and blockade by charybdotoxin and econazole. These results strongly suggest that SK4 encodes IK channels in MBM.