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Characterization of stretch‐activated ion channels in cultured astrocytes
Author(s) -
Islas Leon,
PasantesMorales Herminia,
Sanchez Jorge A.
Publication year - 1993
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.440080204
Subject(s) - biophysics , biology , ion channel , neuroscience , biochemistry , receptor
The presence of a stretch‐activated channel in rat cerebellar astrocytes in culture is described. This stretch‐sensitive channel is K + ‐selective and its open probability increases with suction following a Boltzmann‐like distribution with half activation at 45 mm Hg. Kinetic analysis of the single‐channel data indicated that there are two open and two closed states and that the shortest time constants of both open and closed states are the most sensitive to suction. A symmetrical two‐barrier‐one‐site permeation model can quantitatively describe the inward rectification of the single‐channel current to voltage relations. It is suggested that this stretch‐activated channel plays a role in the regulatory volume response of astrocytes to hyposmotic conditions. © 1993 Wiley‐Liss, Inc.