Effect of catechol-O-methyl transferase inhibition on peripheral and central metabolism of 6-[18F]fluoro-L-DOPA
| Autor: | Serge Goldman, Thierry Pauwels, André Luxen, Michel Monclus, Sophie Dethy |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Fluorine Radioisotopes medicine.medical_specialty Catechols Striatum Cerebellum Internal medicine Nitriles medicine Animals Transferase Entacapone Rats Wistar Chromatography High Pressure Liquid Pharmacology Catechol-O-methyl transferase biology Chemistry Carbidopa Catechol O-Methyltransferase Inhibitors Metabolism Corpus Striatum Dihydroxyphenylalanine Rats Endocrinology nervous system Enzyme inhibitor Catecholamine biology.protein medicine.drug |
| Zdroj: | European Journal of Pharmacology. 257:53-58 |
| ISSN: | 0014-2999 |
| Popis: | In the presence of carbidopa, L-3,4-dihydroxy-6-[18F]fluorophenylalanine ([18F]fluoro-DOPA) is mainly metabolized by catechol-O-methyl transferase. We studied the effects of entacapone, a peripheral catechol-O-methyl transferase inhibitor, on striatal [18F]fluoro-DOPA uptake in rats. Rats were pretreated with carbidopa, entacapone or both before high specific activity (> 2 Ci/mmol) [18F]fluoro-DOPA administration. Entacapone alone antagonized the appearance of methylated metabolites in plasma, striatum and cerebellum but did not increase striatal [18F]fluoro-DOPA availability. Entacapone added to carbidopa significantly increased the striatum/cerebellum total radioactivity ratio (1.4 versus 1.2 in rats with carbidopa, 1.0 in controls) but significant levels of methylated metabolites were found in the brain. Entacapone added to carbidopa might increase the striatum/cerebellum total radioactivity ratio in humans undergoing [18F]fluoro-DOPA positron emission tomography (PET) studies. However, the appearance of methylated metabolites in the brain could hamper quantification of the PET data. |
| Databáze: | OpenAIRE |
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