Distinct effects of intranigral L-DOPA infusion in the MPTP rat model of Parkinson's disease
| Autor: | Angela B, Reksidler, Marcelo M S, Lima, Patrícia A, Dombrowski, Gabriela F, Barnabé, Monica L, Andersen, Sergio, Tufik, Maria A B F, Vital |
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| Rok vydání: | 2010 |
| Předmět: |
Male
Neurons Analysis of Variance Tyrosine 3-Monooxygenase Dopamine Movement Neurotoxins Cell Count Homovanillic Acid Rats Antiparkinson Agents Levodopa Substantia Nigra Disease Models Animal Gene Expression Regulation Parkinsonian Disorders 1-Methyl-4-phenyl-1 2 3 6-tetrahydropyridine Reaction Time 3 4-Dihydroxyphenylacetic Acid Animals Drug Interactions Rats Wistar |
| Zdroj: | Journal of neural transmission. Supplementum. (73) |
| ISSN: | 0303-6995 |
| Popis: | The potential neuroprotective or neurotoxic effects of 3,4-dihydroxyphenylalanine (L-DOPA) are yet to be understood. We examined the behavioral, immunohistochemical, tyrosine hydroxylase (TH) expression and neurochemical parameters after an intranigral administration of L-DOPA (10 microM) in rats. L-DOPA elicited a 30.5% reduction in dopaminergic neurons, while 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (100 microg microL(-1)) produced a 53.6% reduction. A combined infusion of MPTP and L-DOPA generated a 42% reduction of nigral neurons. Motor parameters revealed that both the MPTP and L-DOPA groups presented impairments; however, the concomitant administration evoked a partial restorative effect. In addition, MPTP and L-DOPA separately induced reductions of TH protein expression within the substantia nigra. In contrast, the coadministration of MPTP and L-DOPA did not demonstrate such difference. The striatal levels of dopamine were reduced after MPTP or L-DOPA, with an increased turnover only for the MPTP group. In view of such results, it seems reasonable to suggest that L-DOPA could potentially produce dopaminergic neurotoxicity. |
| Databáze: | OpenAIRE |
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