The role of -SH groups in methylmercuric chloride-induced d-aspartate and rubidium release from rat primary astrocyte cultures

K. J. Mullaney, M. N. Fehm, D. Vitarella, D. E. Wagoner, Michael Aschner

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

Methylmercuric chloride (MeHgCl) was shown to increase d-aspartate and rubidium (Rb; a marker for potassium) release from preloaded astrocytes in a dose- and time-dependent fashion. Two sulfhydryl (-SH) protecting agents: a cell membrane non-penetrating compound, reduced glutathione (GSH), and the membrane permeable dithiothreitol (DTT), were found to inhibit the stimulatory action of MeHgCl on the efflux of radiolabeled d-aspartate as well as Rb. MeHgCl-induced d-aspartate and Rb release was completely inhibited by the addition of 1 mM DTT or GSH during the actual 5 min perfusion period with MeHgCl (10 μM). However, when added after MeHgCl treatment, this inhibition could not be fully sustained by GSH, while DTT fully inhibited the MeHgCl-induced release of d-aspartate. Neither DTT or GSH alone had any effect on the rate of astrocytic d-aspartate release. Accordingly, it is postulated that the stimulatory effect exerted by MeHgCl on astrocytic d-aspartate release is associated with vulnerable -SH groups located within, but not on the surface of the cell membrane. Omission of Na+ from the perfusion solution did not accelerate MeHgCl-induced d-aspartate release, suggesting that reversal of the d-aspartate carrier cannot be invoked to explain MeHgCl-induced d-aspartate release. Omission of Ca2+ from the perfusion solution increased the time-dependent MeHgCl-induced d-aspartate release.

Original languageEnglish (US)
Pages (from-to)1-9
Number of pages9
JournalBrain Research
Volume641
Issue number1
DOIs
StatePublished - Mar 28 1994
Externally publishedYes

Fingerprint

Rubidium
Aspartic Acid
Astrocytes
Dithiothreitol
Perfusion
Cell Membrane
methylmercuric chloride
Glutathione
Potassium

Keywords

  • -SH group
  • Astrocyte
  • d-Aspartate
  • Methylmercuric chloride
  • Rubidium

ASJC Scopus subject areas

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

Cite this

The role of -SH groups in methylmercuric chloride-induced d-aspartate and rubidium release from rat primary astrocyte cultures. / Mullaney, K. J.; Fehm, M. N.; Vitarella, D.; Wagoner, D. E.; Aschner, Michael.

In: Brain Research, Vol. 641, No. 1, 28.03.1994, p. 1-9.

Research output: Contribution to journalArticle

Mullaney, K. J. ; Fehm, M. N. ; Vitarella, D. ; Wagoner, D. E. ; Aschner, Michael. / The role of -SH groups in methylmercuric chloride-induced d-aspartate and rubidium release from rat primary astrocyte cultures. In: Brain Research. 1994 ; Vol. 641, No. 1. pp. 1-9.
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