Acidic pH rapidly increases immunoreactivity of glial fibrillary acidic protein in cultured astrocytes

✍ Scribed by Dr. Tae H. Oh; George J. Markelonis; Jon R. Von Visger; Bonsook Baik; Michael T. Shipley

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 463 KB
• Volume: 13
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/glia.440130408

✦ Synopsis

Neuroepithelial progenitor cells from forebrains of newborn rat pups develop into "mature" astrocytes in an epidermal growth factor-containing medium free of serum (Von Visger et al: Exp Neurol128:34,1994). Eight-week-old "mature" astrocyte cultures on poly-L-lysine-coated dishes were exposed to an acidic medium (pH 5.8-6.0) for 2-6 h. Immunoreactivity for glial fibrillary acidic protein (GFAP) dramatically and rapidly increased; this immediate increase was not affected by pretreatment with cycloheximide. In further experiments we found that the increase in GFAP was undiminished for 24-48 h after the acid-treated astrocytes were returned to normal growth medium. The Ca2+ channel antagonists nifedipine and diltiazem attenuated the increase in GFAP immunoreactivity. These results suggest that extracellular acidosis may produce a rapid increase in GFAP immunoreactivity in astrocytes independent of de novo protein synthesis, possibly by increasing intracellular levels of free Ca2+ ions. o 1995 Wiley-Liss, Inc.