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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
20
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pubmed:dateCreated |
1987-8-13
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pubmed:abstractText |
The influx of 5'-deoxy-5'-methylthioadenosine (MeSAdo) into human HL-60 leukemia cells and erythrocytes was characterized in order to determine whether it is facilitated by the nonspecific nucleoside carrier system or by a separate transporter, as suggested by other reports. Initial velocities were measured at room temperature by means of inhibitor-stop and oil-stop assays. MeSAdo influx was strongly inhibited by Ado, dAdo, and nucleoside transport inhibitors including nitrobenzylthioinosine and dipyridamole. Ade was inhibitory only at concentrations in excess of 1 mM. Loss of nucleoside transport capacity during differentiation of HL-60 cells was accompanied by a corresponding decrease in MeSAdo influx rates. These results indicate that MeSAdo influx was mediated by the nonspecific nucleoside transport system. The kinetic data were consistent with a single saturable carrier and yielded Km values of 74 and 184 microM and Vmax values of 424 and 48 pmols/10(6) cells/min with HL-60 cells and erythrocytes, respectively, after correction for a substantial passive diffusion component, which accounted for over 50% of the influx of 1 mM MeSAdo. The passive diffusion of MeSAdo in the presence of a transport inhibitor was not rate-limiting for the salvage of 50 microM MeSAdo to methionine when HL-60 cells were cultured in methionine-deficient medium. The large contribution of passive diffusion to the influx of MeSAdo is consistent with its unusually high octanol/water partition ratio (5.7-fold greater than that of Ado).
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/5'-methylthioadenosine,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine,
http://linkedlifedata.com/resource/pubmed/chemical/Deoxyadenosines,
http://linkedlifedata.com/resource/pubmed/chemical/Thionucleosides,
http://linkedlifedata.com/resource/pubmed/chemical/Vasodilator Agents
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
262
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
9542-6
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:3474231-Adenosine,
pubmed-meshheading:3474231-Biological Transport,
pubmed-meshheading:3474231-Cell Line,
pubmed-meshheading:3474231-Deoxyadenosines,
pubmed-meshheading:3474231-Erythrocytes,
pubmed-meshheading:3474231-Humans,
pubmed-meshheading:3474231-Kinetics,
pubmed-meshheading:3474231-Leukemia, Myeloid, Acute,
pubmed-meshheading:3474231-Thionucleosides,
pubmed-meshheading:3474231-Vasodilator Agents
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pubmed:year |
1987
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pubmed:articleTitle |
Influx of 5'-deoxy-5'-methylthioadenosine into HL-60 human leukemia cells and erythrocytes.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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