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Characterization of potassium channels in pancreatic β cells from ob / ob mice
Author(s) -
Kukuljan Manuel,
Li Min Yi,
Atwater Illani
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)81518-s
Subject(s) - potassium channel , potassium , chemistry , endocrinology , islet , medicine , pancreatic islets , membrane potential , biophysics , patch clamp , in vivo , microbiology and biotechnology , electrophysiology , biology , biochemistry , insulin , organic chemistry
The patch‐clamp technique in the cell‐attached mode was used to study the K channels present in the membrane of cultured pancreatic β cells from ob / ob mice. Three types of K + channels were regularly observed, with conductances of 64, 20 and 146 pS. The conduction and kinetic properties of the 64 pS channel were similar to those of the ATP‐sensitive potassium channel from normal β cells. Furthermore, glucose blocked the activity of this channel at the same concentrations as that reported for normal cells. The 20 pS and the 146 pS were insensitive to glucose. The latter K + channel appears to be similar to the large conductance voltage‐activated potassium channels described in normal rodent β cells. Thus, potassium channels in ob / ob pancreatic β cells in culture are in most respects normal. Other factors may account for the abnormal electrical response to glucose of ob / ob pancreatic islets, such as reversible impairment of their function in vivo or defects not related to potassium permeability.