The role of -SH groups in methylmercuric chloride-induced D-aspartate and rubidium release from rat primary astrocyte cultures.
Brain Res
; 641(1): 1-9, 1994 Mar 28.
Article
em En
| MEDLINE
| ID: mdl-8019833
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 microM). 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.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Rubídio
/
Compostos de Sulfidrila
/
Astrócitos
/
Ácido Aspártico
/
Compostos de Metilmercúrio
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1994
Tipo de documento:
Article