Effect of external acidosis on basal and ATP-evoked calcium influx in cultured astrocytes

J. T. Neary, Q. Fu, A. S. Bender, Michael D Norenberg

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

The effect of lactic acidosis on calcium influx, accumulation and efflux was studied in primary cultures of neonatal cortical rat astrocytes. Treatment of cultures with 20 mM sodium lactate, pH 6.0, for 10-60 min resulted in a 35% reduction of 45Ca2+ influx. The decrease in calcium influx was pH dependent because a similar reduction was observed in cultures exposed to pH 6.0 without lactate, while no difference was observed in cultures treated with sodium lactate at pH 7.4. Calcium accumulation was also decreased by lactic acidosis (20% reduction), while calcium efflux was unaffected. Studies with lanthanum, an inhibitor of calcium transport, indicated that the effect of lactic acidosis was not due to non-specific leakage of calcium. The reduction in calcium influx was reversible, thereby indicating that the cells were not permenantly damaged by lactic acidosis. In addition to basal calcium influx, stimulated influx (mediated by extracellular ATP, 100 μM) was also reduced by 20 mM sodium lactate, pH 6. These findings suggest that protonization of calcium channels or other calcium entry pathways leads to a reduction in calcium influx in astrocytes. This diminished calcium entry, by affecting calcium-dependent mechanisms necessary for such processes as volume regulation, glycogen metabolism, or regulation of ionic permeability, may alter the ability of astrocytes to elicit appropriate responses following CNS injury.

Original languageEnglish
Pages (from-to)211-216
Number of pages6
JournalBrain Research
Volume604
Issue number1-2
DOIs
StatePublished - Feb 26 1993

Fingerprint

Acidosis
Astrocytes
Adenosine Triphosphate
Calcium
Lactic Acidosis
Sodium Lactate
Lanthanum
Calcium Channels
Glycogen
Permeability
Lactic Acid

Keywords

  • Acidosis
  • Astrocyte
  • Calcium
  • Extracellular ATP
  • Lactic acid
  • Purinergic receptor

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Effect of external acidosis on basal and ATP-evoked calcium influx in cultured astrocytes. / Neary, J. T.; Fu, Q.; Bender, A. S.; Norenberg, Michael D.

In: Brain Research, Vol. 604, No. 1-2, 26.02.1993, p. 211-216.

Research output: Contribution to journalArticle

Neary, J. T. ; Fu, Q. ; Bender, A. S. ; Norenberg, Michael D. / Effect of external acidosis on basal and ATP-evoked calcium influx in cultured astrocytes. In: Brain Research. 1993 ; Vol. 604, No. 1-2. pp. 211-216.
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