Dopamine transporters are involved in the onset of hypoxia-induced dopamine efflux in striatum as revealed by in vivo microdialysis
| Autor: | Jean-Marc Pequignot, Luc Denoroy, J. M. Cottet-Emard, Cyrille Orset, Anne Bérod, Sandrine Parrot, Valérie Sauvinet |
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| Rok vydání: | 2005 |
| Předmět: |
Male
medicine.medical_specialty Microdialysis Nomifensine Dopamine Nerve Tissue Proteins Biology Rats Sprague-Dawley Cellular and Molecular Neuroscience chemistry.chemical_compound Neurochemical Dopamine Uptake Inhibitors Membrane Transport Modulators Internal medicine medicine Animals Hypoxia Brain Neurotransmitter Dopamine transporter Neurons Dopamine Plasma Membrane Transport Proteins Membrane Glycoproteins Membrane Transport Proteins Extracellular Fluid Cell Biology Hypoxia (medical) Adaptation Physiological Corpus Striatum Rats Up-Regulation Disease Models Animal Endocrinology chemistry biology.protein Catecholamine 3 4-Dihydroxyphenylacetic Acid medicine.symptom Sodium Channel Blockers medicine.drug |
| Zdroj: | Neurochemistry International. 46:623-633 |
| ISSN: | 0197-0186 |
| Popis: | Although many studies have revealed alterations in neurotransmission during ischaemia, few works have been devoted to the neurochemical effects of mild hypoxia, a situation encountered during life in altitude or in several pathologies. In that context, the present work was undertaken to determine the in vivo mechanisms underlying the striatal dopamine efflux induced by mild hypoxaemic hypoxia. For that purpose, the extracellular concentrations of dopamine and its metabolite 3,4-dihydroxyphenyl acetic acid were simultaneously measured using brain microdialysis during acute hypoxic exposure (10% O2, 1 h) in awake rats. Hypoxia induced a +80% increase in dopamine. Application of the dopamine transporters inhibitor, nomifensine (10 μM), just before the hypoxia prevented the rise in dopamine during the early part of hypoxia; in contrast the application of nomifensine after the beginning of hypoxia, failed to alter the increase in dopamine. Application of the voltage-dependent Na+ channel blocker tetrodotoxin abolished the increase in dopamine, whether administered just before or after the beginning of hypoxia. These data show that the neurochemical mechanisms of the dopamine efflux may change over the course of the hypoxic exposure, dopamine transporters being involved only at the beginning of hypoxia. |
| Databáze: | OpenAIRE |
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