Effects of monoamine oxidase and catechol-O-methyltransferase inhibition on dopamine turnover: a PET study with 6-[18F]L-DOPA.
Eur J Pharmacol
; 334(1): 31-8, 1997 Sep 03.
Article
em En
| MEDLINE
| ID: mdl-9346324
ABSTRACT
The consequences of monoamine oxidase and catechol-O-methyltransferase inhibition on the effective turnover of dopamine were investigated using 6-[18F]L-3-4-dihydroxyphenylalanine (6-[18F]L-DOPA) and positron emission tomography. The effective dopamine turnover was expressed as the ratio between the rate of reversibility of 6-[18F]L-DOPA trapping (k[loss]) and the rate of uptake of 6-[81F]L-DOPA (Ki) in the striatum of normal cynomolgus monkeys. The monkeys received 6-[18F]L-DOPA scans, untreated or after pretreatment with either the peripheral catechol-O-methyltransferase inhibitor nitecapone; the peripheral and central catechol-O-methyltransferase inhibitor tolcapone; the monoamine oxidase inhibitors deprenyl or pargyline; a combination of tolcapone and the monoamine oxidase inhibitors. Tolcapone alone or combined with the monoamine oxidase inhibitors produced a significant decrease in the dopamine turnover (55 to 65%). Neither nitecapone nor monoamine oxidase inhibition alone produced significant changes. These results may have implications for the use of central catechol-O-methyltransferase inhibitors added to routine levodopa therapy in parkinsonian patients.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pentanonas
/
Benzofenonas
/
Dopamina
/
Levodopa
/
Catecóis
/
Inibidores Enzimáticos
/
Inibidores de Catecol O-Metiltransferase
/
Inibidores da Monoaminoxidase
/
Antiparkinsonianos
Limite:
Animals
Idioma:
En
Revista:
Eur J Pharmacol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Canadá