Opposite presynaptic regulations by glutamate through NMDA receptors of dopamine synthesis and release in rat striatal synaptosomes
| Autor: | Jacques Glowinski, André Chéramy, Thierry Galli, J. M. Desce, G Godeheu |
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| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Quinpirole Adenosine Deaminase Dopamine Dopamine Agents 8-Bromo Cyclic Adenosine Monophosphate Glutamic Acid Kainate receptor AMPA receptor In Vitro Techniques Biology Receptors Presynaptic Models Biological Receptors N-Methyl-D-Aspartate Rats Sprague-Dawley Body Water Glutamates Internal medicine medicine Animals Ergolines Tyrosine Molecular Biology Synaptosome Tyrosine hydroxylase Ionomycin General Neuroscience Glutamate receptor Glutamic acid Rats Neostriatum Endocrinology NMDA receptor Neurology (clinical) Synaptosomes Developmental Biology |
| Zdroj: | Brain Research. 640:205-214 |
| ISSN: | 0006-8993 |
| Popis: | Purified striatal synaptosomes were superfused continuously with L-[3,5-3H]tyrosine to measure simultaneously the synthesis ([3H]water formed during the conversion of [3H]tyrosine into [3H]DOPA) and the release of [3H]dopamine ([3H]DA). Glutamate (10(-3) M) and NMDA (10(-3) M, in the absence of Mg2+) stimulated the release of [3H]DA, but they reduced the efflux of [3H]water. This reduction of [3H]DA synthesis was blocked by 2-amino-5-phosphonovalerate indicating the involvement of NMDA receptors. Although D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole-4-propionate (AMPA) and kainate stimulated the release of [3H]DA, they did not affect its synthesis. The glutamate-evoked inhibition of [3H]DA synthesis was prevented when synaptosomes were superfused continuously with adenosine deaminase plus quinpirole, a treatment which markedly reduces the phosphorylation of tyrosine hydroxylase by cAMP dependent protein kinase. The opposite effects of glutamate on [3H]DA synthesis and release were mimicked by ionomycin (10(-6) M). It is proposed that both an activation of a cyclic nucleotide phosphodiesterase and a dephosphorylation of tyrosine hydroxylase linked to the influx of calcium through NMDA receptors is responsible for the inhibition of dopamine synthesis by glutamate and that calcineurin could play a critical role in these processes. |
| Databáze: | OpenAIRE |
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