Linked Life Data

8215248

Source:http://linkedlifedata.com/resource/pubmed/id/8215248

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1993-11-12
pubmed:abstractText
The transport of L-6-fluorodopa and its major metabolites from the blood to the brain, cerebrospinal fluid (CSF), and muscle was studied in carbidopa-pretreated cynomolgus monkeys. A bolus intravenous injection of 18F-L-6-fluorodopa was followed by serial positron emission tomography scans and sampling of cisternal CSF and arterial blood. The relative concentrations of L-6-fluorodopa and its metabolites were determined in blood plasma and CSF by high-performance liquid chromatography. Raising the blood concentration of phenylalanine by intraperitoneal injection markedly reduced the accumulation of tracer in the brain. This indicates that L-6-fluorodopa and 3-O-methylfluorodopa, like native L-dopa and its O-methylated derivative, are transported at the brain capillary by the large neutral amino acid carrier-mediated system, which is subject to saturation and competition by other large neutral amino acids (such as phenylalanine) at physiological plasma concentrations. In contrast, administration of phenylalanine had no effect on the accumulation of tracer either in muscle, or as L-6-fluorodopa and 3-O-methylfluorodopa, in CSF. This suggests that the transport of L-dopa and its derivatives at the blood-CSF barrier differs from the transport at the blood-brain barrier and also that measurement of CSF L-dopa is not a good index of the transport and pharmacokinetics of L-dopa in the brain. However, the effect of phenylalanine administration in reducing the concentration of fluorohomovanillic acid in the CSF suggests that the concentration of homovanillic acid in the CSF is an accurate reflection of dopamine turnover in the brain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0364-5134
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
603-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
The transport of L-6-fluorodopa and its metabolites from blood to cerebrospinal fluid and brain.
pubmed:affiliation
Neurodegenerative Disorders Centre, University of British Columbia, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't