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Gonzalez A, Granados MP, Pariente JA, Salido GM.
H2O2
Mobilizes Ca2+ from Agonist- and Thapsigargin
-sensitive and Insensitive Intracellular Stores and
Stimulates Glutamate Secretion in Rat Hippocampal Astrocytes.
Neurochem Res. 2006 Jun;31(6):741-50
The effect of hydrogen peroxide (H2O2) on cytosolic free
calcium concentration ([Ca2+]c) as well as its effect on
glutamate secretion in rat hippocampal astrocytes have been the
aim of the present research. Our results show that 100 microM
H2O2 induces an increase in [Ca2+]c, that remains at an elevated
level while the oxidant is present in the perfusion medium, due
to its release from intracellular stores as it was observed in
the absence of extracellular Ca2+, followed by a significant
increase in glutamate secretion. Ca2+-mobilization in response
to the oxidant could only be reduced by thapsigargin plus FCCP,
indicating that the Ca2+-mobilizable pool by H2O2 includes both
endoplasmic reticulum and mitochondria. We conclude that ROS in
hippocampal astrocytes might contribute to an elevation of
resting [Ca2+]c which, in turn, could lead to a maintained
secretion of the excitatory neurotransmitter glutamate, which
has been considered a situation potentially leading to
neurotoxicity in the hippocampus.
PMID: 16794860
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