Improvement of ischemic damage in gerbil hippocampal neurons by procaine

Junfeng Chen, Naoto Adachi, Keyue Liu, Takumi Nagaro, Tatsuru Arai

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19 Citations (Scopus)

Abstract

Acute cerebral ischemia induces membrane depolarization in the neuron, thereby incurring the simultaneous influx of various ions such as Na+ and Ca2+. Since procaine possesses the ability to inhibit the release of Ca2+ from intracellular Ca2+ stores to the cytosol as well as the ability to block Na+ channels, the effects of procaine on ischemia were investigated in the present study in gerbils both in vivo and in vitro. The histologic outcome was evaluated 7 days after 3 min of transient forebrain ischemia by assessing delayed neuronal death in hippocampal CA1 pyramidal cells in animals administered procaine (0.2, 0.4, or 2 μmol) intracerebroventricularly 10 min before ischemia and in animals given saline. The changes in the direct-current potential shift in the hippocampal CA1 area were measured using an identical animal model. A hypoxia-induced intracellular Ca2+ increase was evaluated by in vitro microfluorometry in gerbil hippocampal slices, and the effects of procaine (10, 50, and 100 μmol/l) on the Ca2+ accumulation were examined. Additionally, the effect of procaine (100 μmol/l) in a Ca2+-free condition was investigated. The histologic outcome was improved and the onset of the ischemia-induced membrane depolarization was prolonged by the preischemic administration of procaine. The increase in the intracellular concentration of Ca2+ induced by the in vitro hypoxia was suppressed by the perfusion of procaine- containing mediums (50 and 100 μmol/l), regarding both the initiation and the extent of the increase. A hypoxia-induced intracellular Ca2+ elevation in the Ca2+-free condition was observed, and the perfusion with procaine (100 μmol/l) inhibited this elevation. Procaine helps protect neurons from ischemia by suppressing the direct-current potential shift and by inhibiting the release of Ca2+ from the intracellular Ca2+ stores, as well as by inhibiting the influx of Ca2+ from the extracellular space.

Original languageEnglish
Pages (from-to)16-23
Number of pages8
JournalBrain Research
Volume792
Issue number1
DOIs
Publication statusPublished - May 4 1998

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Keywords

  • Anoxic depolarization
  • Ca2
  • Cerebral ischemia
  • Gerbil
  • Hippocampus
  • Procaine

ASJC Scopus subject areas

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

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