Epidermal growth factor activates calcium-permeable channels in A 431 cells.
The patch clamp technique in a cell-attached configuration was used to search for calcium-permeable channels in human carcinoma A 431 cells. Unitary inward currents were recorded with 100 mM CaCl2 in a pipette, with the mean slope conductance of 2.8 pS and a reversal potential (obtained by extrapolation) of +25.5 mV. Application of epidermal growth factor (EGF) into the extracellular solution produced a transient increase in the probability of these channels being open. The effect develops with delay of about 20 s and lasts thereafter for 36 s (mean values). We propose that these channels mediate an EGF-induced increase in the concentration of cytosolic free calcium.
Mozhayeva
G N
GN
Academy of Sciences of the U.S.S.R., Institute of Cytology, Leningrad.
Naumov
A P
AP
Kuryshev YuA
D015220:Calcium Channels / Q000378:metabolism*; D002463:Cell Membrane Permeability; D004815:Epidermal Growth Factor / Q000502:physiology*; D006801:Humans; D008564:Membrane Potentials; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D004815:Epidermal Growth Factor