L-Glutamate (L-GLU) induced astrocyte swelling in a time- and concentration-dependent, as well as Na+and Ca2+-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 Ca2+ and Na+, but not on Cl-. Likewise, K+ uptake was inhibited by MK-801, cystine, and ouabain. The K+ channel blockers, Ba2+ 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.
|Original language||English (US)|
|Number of pages||15|
|Journal||Journal of Neuroscience Research|
|State||Published - May 1 1998|
- Glutamate swelling
- Potassium uptake
ASJC Scopus subject areas