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Low‐conductance chloride channel activated by cAMP in the epithelial cell line T 84
Author(s) -
Tabcharani J.A.,
Low W.,
Elie D.,
Hanrahan J.W.
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)81257-o
Subject(s) - dids , conductance , chloride channel , biophysics , extracellular , chemistry , chloride , inward rectifier potassium ion channel , electrophysiology , membrane potential , ion channel , endocrinology , medicine , biochemistry , membrane , biology , physics , receptor , organic chemistry , condensed matter physics
We have studied the modulation and pharmacological properties of two anion channels in T 84 cells by recording single channel and transepithelial currents. One channel had an outwardly rectifying current‐voltage I/V curve, was rarely active in cell‐attached patches, and was unaffected by cAMP. The other channel had lower conductance (8.7 pS at 37°C) and a more ohmic I/V relationship. Exposure to cAMP increased the probability of observing low‐conductance channel activity in cell‐attached patches > 6‐fold. Extracellular DIDS (4,4'‐diisothiocyanatostilbene‐2,2'‐disulfonic acid) or IAA‐94 (an indanyloxyacetic acid) inhibited the outward rectifier but did not affect the low‐conductance channel or cAMP‐stimulated transepithelial current. These results suggest the low‐conductance Cl channel may contribute to apical membrane conductance during cAMP‐stimulated secretion.