Characterization of subtypes of excitatory amino acid receptors involved in the stimulation of inositol phosphate synthesis in rat brain synaptoneurosomes
| Autor: | Agnès Nourigat, Fritz Sladeczek, Max Récasens, Isabelle Sassetti, Joël Bockaert |
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| Rok vydání: | 1987 |
| Předmět: |
Male
medicine.medical_specialty Aging Inositol Phosphates Stimulation Kainate receptor Receptors Cell Surface Tetrodotoxin Biology In Vitro Techniques chemistry.chemical_compound Internal medicine medicine Animals Receptors Amino Acid Inositol Receptor Pharmacology Synaptosome Brain Chemistry Neurons Glutamate receptor Rats Endocrinology chemistry Excitatory postsynaptic potential NMDA receptor Calcium Female Sugar Phosphates Synaptosomes |
| Zdroj: | European journal of pharmacology. 141(1) |
| ISSN: | 0014-2999 |
| Popis: | The action of excitatory amino acids (EAA) on inositol phosphates (IPs) synthesis was examined in forebrain synaptoneurosomes of Long Evans rats (6-9 days old). Glutamate (GLU) (EC50: 23 microM) and quisqualate (QA) (EC50: 0.12 microM) enhanced IPs turnover. N-methyl-D-aspartate (NMDA) and kainate (KA) were less potent. The EAA-elicited IPs response was not blocked by tetrodotoxin (2 microM) or by the absence of Ca2+. This suggests that the activation of EAA receptors stimulates directly the phosphodiesterase responsible for phosphoinositide breakdown. The three main agonists (QA, KA and NMDA) tested in pairs, induced additive responses on IPs accumulation. In synaptoneurosomes prepared from adult rat, the relative responses to QA and GLU were dramatically reduced, whereas those to KA and NMDA remained unchanged. We concluded that GLU stimulates IPs formation mainly via a QA-like receptor subtype (AA2). This stimulation is transient and could play a key role during synaptogenesis. GLU also enhanced IPs accumulation via other receptor subtypes (probably of the NMDA- or AA1-like class). |
| Databáze: | OpenAIRE |
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