Distinct effects of intranigral L-DOPA infusion in the MPTP rat model of Parkinson's disease.
J Neural Transm Suppl
; (73): 259-68, 2009.
Article
em En
| MEDLINE
| ID: mdl-20411784
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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Substância Negra
/
Levodopa
/
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina
/
Transtornos Parkinsonianos
/
Neurotoxinas
/
Antiparkinsonianos
Limite:
Animals
Idioma:
En
Revista:
J Neural Transm Suppl
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Áustria