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A novel hypertonicity‐induced cation channel in primary cultures of human hepatocytes
Author(s) -
Li Tongju,
ter Veld Frank,
Nürnberger Hartwig R.,
Wehner Frank
Publication year - 2005
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/j.febslet.2005.02.060
Subject(s) - amiloride , chemistry , biophysics , extracellular , epithelial sodium channel , sodium , biochemistry , biology , organic chemistry
In whole‐cell recordings on primary cultures of human hepatocytes, we observe the hypertonic activation of a novel type of cation channel with a permeability ratio for Na + :Li + :K + :Cs + :NMDG + of 1:1.2:1.3:1.2:0.6. With a P Ca / P Na of 0.7 the channel is also clearly permeable to Ca ++ . Most likely, the channel is Cl − impermeable but its activity critically depends on the extracellular Cl − concentration (with the half maximal effect at 88 mmol/l). With a 64% inhibition by amiloride and a complete block by flufenamate and Gd 3+ (at 100 μmol/l each), the channel may represent a molecular link between the amiloride‐sensitive and insensitive channels reported so far.