Control of astrocyte volume by intracellular and extracellular Ca2+

✍ Scribed by James E. Olson; Deborah Fleischhacker; W. Bruce Murray; David Holtzman

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 841 KB
• Volume: 3
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/glia.440030512

✦ Synopsis

Abstract

Astrocytes from primary culture were exposed to conditions that affect intracellular and extracellular Ca^2+^ concentrations. Astrocyte cell volume was increased approximately 16% after a 30 min exposure to isoosmotic phosphate‐buffered saline (PBS) containing the Ca^2+^ buffer EDTA. Cell volume returned to control values within 30 min of resuspension in normal PBS. Cellular calcium content was not affected by these treatments; however, the recovery of normal cell volume following EDTA exposure was inhibited by 0.1–1.0 mM quinine HCl in a dose‐dependent fashion suggesting that a potassium channel controlled by the intracellular Ca^2+^ concentration is important in this volume response. Intracellular accumulation of an exogenous Ca^2+^ buffer, BAPTA, also produced cell swelling that persisted following resuspension in normal PBS. Lowering the extracellular Ca^2+^ concentration with EDTA enhanced the swelling of BAPTA‐loaded cells. These data suggest that conditions leading to a decrease in free intracellular Ca^2+^ concentration may influence astrocyte volume by a mechanism similar to that described in other cell types.