Sodium ions regulate a specific population of acidic amino acid receptors in synaptic membranes.

Details

Serval ID
serval:BIB_F2E7D7EF41F7
Type
Article: article from journal or magazin.
Collection
Publications
Title
Sodium ions regulate a specific population of acidic amino acid receptors in synaptic membranes.
Journal
Life Sciences
Author(s)
Fagg G.E., Riederer B., Matus A.
ISSN
0024-3205 (Print)
ISSN-L
0024-3205
Publication state
Published
Issued date
1984
Volume
34
Number
18
Pages
1739-1745
Language
english
Abstract
The regulatory effects of Na+ on C1-/Ca2+-dependent and C1-/Ca2+-independent L-glutamate binding sites were examined. In Tris-C1-/Ca2+ buffer, the binding of L-[3H]-glutamate to rat brain synaptic membranes was 5-fold higher than in Tris-acetate buffer. Low concentrations of Na+ (less than 5 mM) markedly depressed L-glutamate binding when assayed in Tris-C1/Ca2+ buffer, and this effect was attenuated by the selective blocker of C1-/Ca2+-dependent binding sites, DL-2-amino-4-phosphonobutyrate (APB). Scatchard analyses indicated that the effect of Na+ was due to a decrease in the number of C1-/Ca2+-dependent binding sites with no change in affinity. In Tris-acetate buffer, low concentrations of Na+ had little effect on L-glutamate binding. Dose-response curves for the inhibition of L-glutamate binding by DL-APB indicated a predominant high-affinity (Ki 5-10 microM) inhibitory component in Tris-C1-/Ca2+ buffer, but mainly a low-affinity component (Ki 1-2 mM) in Tris-acetate buffer and in Tris-C1-/Ca2+ buffer containing Na+. These data indicate that low concentrations of Na+ regulate specifically the C1-/Ca2+-dependent, APB-sensitive class of L-glutamate binding sites.
Keywords
Aminobutyrates/pharmacology, Animals, Binding Sites, Depression, Chemical, Dose-Response Relationship, Drug, Glutamates/metabolism, Kinetics, Male, Rats, Receptors, Cell Surface/metabolism, Receptors, Glutamate, Sodium/physiology, Synaptic Membranes/metabolism
Pubmed
Web of science
Create date
24/01/2008 14:34
Last modification date
20/08/2019 16:20
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