A novel chloride-dependent L-[3H]glutamate binding site in astrocyte membranes
| Autor: | Richard J. Bridges, Munaf Kadri, Carl W. Cotman, Manuel Nieto-Sampedro |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Glutamic Acid
Kainate receptor Biology Biochemistry Cellular and Molecular Neuroscience Chlorides Glutamates medicine Animals Binding site Amino Acids Cells Cultured Cerebral Cortex Cell Membrane Glutamate receptor Glutamate binding Rats Inbred Strains Glutamic acid Ligand (biochemistry) Rats Receptors Neurotransmitter Kinetics medicine.anatomical_structure Membrane Receptors Glutamate Astrocytes Astrocyte |
| Zdroj: | Journal of neurochemistry. 48(6) |
| ISSN: | 0022-3042 |
| Popis: | Membrane fractions prepared from astrocytes grown in culture exhibit a specific binding site for L-[3H]glutamate that is Cl--dependent and Na+-independent. The binding site is a single saturable site with a KD of about 0.5 microM, is inhibited by L-aspartate, L-cysteate, and quisqualate, and is insensitive to kainate, N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate, and 2-amino-4-phosphonobutyrate. The pharmacological characteristics of the binding site indicate that it is distinct from any site previously described in synaptic membrane preparations. Comparisons of ionic requirements, ligand specificity, and inhibitor sensitivities, however, suggest the described binding is the first step in a Cl--dependent high-affinity glutamate uptake system. Such binding studies provide a useful model system in which to investigate the close association between excitatory amino acids, astrocytes, the termination of glutamate's excitatory action by high-affinity uptake, and the excitotoxic action of acidic amino acids in membranes of a single cell type. |
| Databáze: | OpenAIRE |
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