Source:http://linkedlifedata.com/resource/pubmed/id/10541825
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
10
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| pubmed:dateCreated |
2000-2-17
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| pubmed:abstractText |
3-[(123)I]Iodo-l-alpha-methyltyrosine ((123)I-IMT) is used for the diagnosis and monitoring of brain tumours by means of single-photon emission tomography (SPET). To date, little has been known about the system for the transport of (123)I-IMT into brain tumour cells. It is assumed that (123)I-IMT is transported by a specific carrier for large, neutral amino acids (L-system). In this study, rat C6 glioma cells were used to characterize the uptake system of (123)I-IMT and to investigate its precise kinetics. The time course of (123)I-IMT uptake into the cells was examined for a range of 1-60 min. (123)I-IMT uptake rates with varying concentrations of (123)I-IMT (2. 5-50 microM) in the medium were quantified to assess the kinetic parameters of (123)I-IMT transport. Furthermore, competition of (123)I-IMT with other amino acids was investigated to identify the distinct transport systems involved in (123)I-IMT uptake. (123)I-IMT uptake into C6 glioma cells was linear for approximately 10 min and reached a steady-state level within 30 min. The analysis of the rate of uptake of (123)I-IMT at different concentrations was concordant with the predominance of a single uptake system. The apparent Michaelis constant (K(m)) of (123)I-IMT was 26.2+/-1.9 microM, and the maximum transport velocity (V(max)) was 35.4+/-1.7 nmol/mg protein per 10 min. 77%+/-10% of (123)I-IMT transport was sodium independent and 23%+/-3% was sodium dependent. Competitive inhibition of (123)I-IMT uptake by 2-aminobicyclo[2.2. 1]heptane-2-carboxylic acid, alpha-(methylamino)isobutyric acid and naturally occurring amino acids revealed a major (123)I-IMT transport via the sodium-independent system L (72%) and a minor uptake via the sodium-dependent system B(0,+) (17%). Our results show that (123)I-IMT transport into C6 glioma cells is principally mediated by the L-system and to a minor extent by the B(0,+)-system. The kinetic parameters of (123)I-IMT uptake are in the range of those of naturally occurring amino acids.
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| pubmed:commentsCorrections | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:month |
Oct
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| pubmed:issn |
0340-6997
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
26
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
1274-8
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| pubmed:dateRevised |
2003-11-14
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| pubmed:meshHeading |
pubmed-meshheading:10541825-Animals,
pubmed-meshheading:10541825-Biological Transport, Active,
pubmed-meshheading:10541825-Brain Neoplasms,
pubmed-meshheading:10541825-Glioma,
pubmed-meshheading:10541825-Indicators and Reagents,
pubmed-meshheading:10541825-Methyltyrosines,
pubmed-meshheading:10541825-Radiopharmaceuticals,
pubmed-meshheading:10541825-Rats,
pubmed-meshheading:10541825-Tumor Cells, Cultured
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| pubmed:year |
1999
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| pubmed:articleTitle |
Kinetics of 3-[(123)I]iodo-l-alpha-methyltyrosine transport in rat C6 glioma cells.
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| pubmed:affiliation |
Department of Nuclear Medicine, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Strasse 33, D-48129 Münster, Germany.
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| pubmed:publicationType |
Journal Article
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