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Small conductance chloride channels in the apical membrane of thyroid cells
Author(s) -
Champigny G.,
Verrier B.,
Gérard C.,
Mauchamp J.,
Lazdunski M.
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)80024-d
Subject(s) - conductance , apical membrane , biophysics , chemistry , thyroid , chloride , chloride channel , membrane , endocrinology , medicine , biochemistry , biology , physics , organic chemistry , condensed matter physics
A small conductance chloride channel has been identified on the apical membrane of porcine thyroid cells using the patch‐clamp technique. In cell attached membrane patches with NaCl in the pipette, the single channel conductance is 5.5 pS. The channel is highly selective for chloride over gluconate and iodide, and is impermeable to Na + , K + and tetraethylammonium ions. The open state probability of the channel is not affected by voltage. The channel activity disappears after excision of the patch. The Cl − channel Mocker 5‐nitro‐2‐(3‐phenylpropylamino)‐benzoate (NPPB) did not affect the activity of the thyroid Cl − channels. Treatment of thyroid cells with 8‐(4‐chlorophenylthio)adenosine‐3',5'‐cyclic monophosphate (8‐chloro‐cAMP) (0.5 mM) prior to giga‐seal formation increased Cl − channel activity in the apical membrane of thyroid cells.