Involvement of the Ca2+‐dependent K+ channel activity in the hyperpolarizing response induced by epidermal growth factor in mammary epithelial cells

FEBS Letters

Cossu, M.Franca²  Maeno, Takashi¹  Enomoto, Kohichi³  Oka, Takami²  Edwards, Charles³ 

[1] Department of Physiology, Shimane Medical University, Izumo, Simane 693, Japan;Laboratoryof Molecular and Cellular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA;Laboratory of Cell Biology and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA

关键词: (Mammary epithelial cell);    Epidermal growth factor;    Ca2+ activation;    K+ channel;    Membrane potential;    Hyperpolarization;   

DOI  :  10.1016/0014-5793(86)80738-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 Ca²⁺-dependent K⁺ channels such as tetraethylammonium (7 mM) or quinine (0.29 mM). Both nifedipine (0.15 mM), a blocker of the Ca²⁺ channel, and ruthenium red (2 mM), an inhibitor of the Ca²⁺-binding site, also reduced the amplitude of the hyperpolarizing response by more than 60%. The Ca²⁺ 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 Ca²⁺-dependent K⁺ channel was involved in the EGF-induced hyperpolarizing response of the mammary epithelial cells.

【 授权许可】

Unknown