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Involvement of the Ca 2+ ‐dependent K + channel activity in the hyperpolarizing response induced by epidermal growth factor in mammary epithelial cells
Author(s) -
Enomoto Kohichi,
Cossu M.Franca,
Maeno Takashi,
Edwards Charles,
Oka Takami
Publication year - 1986
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(86)80738-4
Subject(s) - epidermal growth factor , chemistry , biophysics , microbiology and biotechnology , biology , biochemistry , receptor
Epidermal growth factor (EGF) induces a hyperpolarizing response of 5–20 mV amplitude in mouse mammary epithelial cells in culture. The amplitude of the hyperpolarizing response was reduced by more than 60% within several minutes after addition of blockers of voltage and/or Ca 2+ ‐dependent K + channels such as tetraethylammonium (7 mM) or quinine (0.29 mM). Both nifedipine (0.15 mM), a blocker of the Ca 2+ channel, and ruthenium red (2 mM), an inhibitor of the Ca 2+ ‐binding site, also reduced the amplitude of the hyperpolarizing response by more than 60%. The Ca 2+ ionophore, A23187 (3.8 μM), induced a large hyperpolarization, which was 25–40 mV and lasted about 3 min. These data suggest that activity of the Ca 2+ ‐dependent K + channel was involved in the EGF‐induced hyperpolarizing response of the mammary epithelial cells.