Biomaterial Database

Effect of catechol-O-methyl transferase inhibition on peripheral and central metabolism of 6-[18F]fluoro-L-dopa. 1994

T Pauwels, and S Dethy, and S Goldman, and M Monclus, and A Luxen

PET/Biomedical Cyclotron Unit, ULB-Hôpital Erasme, Brussels, Belgium.

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.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009570	Nitriles	Organic compounds containing the -CN radical. The concept is distinguished from CYANIDES, which denotes inorganic salts of HYDROGEN CYANIDE.	Nitrile
D002230	Carbidopa	An inhibitor of DOPA DECARBOXYLASE that prevents conversion of LEVODOPA to dopamine. It is used in PARKINSON DISEASE to reduce peripheral adverse effects of LEVODOPA. It has no anti-parkinson activity by itself.	Methyldopahydrazine,Carbidopa, (R)-Isomer,Carbidopa, (S)-Isomer,Lodosin,Lodosyn,MK-485,MK-486,MK 485,MK 486,MK485,MK486
D002396	Catechols	A group of 1,2-benzenediols that contain the general formula R-C6H5O2.	Pyrocatechols,o-Dihydroxybenzenes,ortho-Dihydroxybenzenes,o Dihydroxybenzenes,ortho Dihydroxybenzenes
D002531	Cerebellum	The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.	Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D002851	Chromatography, High Pressure Liquid	Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.	Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D003342	Corpus Striatum	Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.	Lenticular Nucleus,Lentiform Nucleus,Lentiform Nuclei,Nucleus Lentiformis,Lentiformis, Nucleus,Nuclei, Lentiform,Nucleus, Lenticular,Nucleus, Lentiform,Striatum, Corpus
D004295	Dihydroxyphenylalanine	A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.	Dopa,3,4-Dihydroxyphenylalanine,3-Hydroxy-DL-tyrosine,Dihydroxyphenylalanine Hydrochloride, (2:1),beta-Hydroxytyrosine,3 Hydroxy DL tyrosine,3,4 Dihydroxyphenylalanine,beta Hydroxytyrosine
D005462	Fluorine Radioisotopes	Unstable isotopes of fluorine that decay or disintegrate emitting radiation. F atoms with atomic weights 17, 18, and 20-22 are radioactive fluorine isotopes.	Radioisotopes, Fluorine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia