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Ionic mechanisms in glutamate‐induced astrocyte swelling: Role of K + influx
Author(s) -
Bender Alex S.,
Schousboe Arne,
Reichelt Winfried,
Norenberg Michael D.
Publication year - 1998
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19980501)52:3<307::aid-jnr7>3.0.co;2-h
Subject(s) - swelling , astrocyte , tetraethylammonium , chemistry , glutamate receptor , biophysics , ouabain , biochemistry , potassium , sodium , biology , endocrinology , materials science , receptor , organic chemistry , composite material , central nervous system
L‐Glutamate (L‐GLU) induced astrocyte swelling in a time‐ and concentration‐dependent, as well as Na + ‐ and Ca 2+ ‐dependent, and Cl ‐ ‐independent manner. Swelling was prevented by MK‐801, cystine, and ouabain. Since L‐GLU swelling is ionically dependent, we determined the role of various ions in such swelling. Our results indicate that K + uptake plays a major role in the mechanism of L‐GLU‐induced astrocyte swelling. Like swelling, K + uptake is dependent on Ca 2+ and Na + , but not on Cl ‐ . Likewise, K + uptake was inhibited by MK‐801, cystine, and ouabain. The K + channel blockers, Ba 2+ and tetraethylammonium, partially prevented L‐GLU‐induced swelling. In addition to K + channels, K + influx may also be mediated through Na + /K + ‐ATPase, as its activity is increased by L‐GLU uptake along with the required Na + . Taken together, the data suggest that K + influx plays a key role in the mechanism of L‐GLU‐mediated astrocyte swelling. J. Neurosci. Res. 52:307–321, 1998. © 1998 Wiley‐Liss, Inc.