Linked Life Data

2909251

Source:http://linkedlifedata.com/resource/pubmed/id/2909251

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-2-9
pubmed:abstractText
Formycin B, a C-nucleoside analog of inosine, is not catabolized by human erythrocytes and mouse P388 leukemia cells and is only very inefficiently phosphorylated in these cells. This relative inertness allows the measurement of its transport into and out of the cells uncomplicated by metabolic conversions. We have measured the zero-trans and equilibrium exchange flux of formycin B in these cells by rapid kinetic techniques. The Michaelis-Menten constants and maximum velocities for formycin B transport in both types of cell were similar to those previously reported for uridine and thymidine. Nevertheless, the differential mobility of the substrate-loaded and empty carrier of human erythrocytes was less for formycin B than uridine as substrate. Formycin B influx was inhibited by other nucleosides in accordance with their affinities for the carrier, but unaffected by purines. The inhibition of formycin B influx by nitrobenzylthioinosine and dipyridamole was also identical to that observed with uridine as substrate (IC50 = 10 and 30 nM, respectively). Formycin B accumulated in both types of cell to 30-40% higher concentrations than were present in the medium. This concentrative accumulation was not due to active transport, metabolism or partitioning into membrane lipids. It seems to reflect binding of formycin B to intracellular components, but does not interfere significantly with measurements of its transport.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
1010
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7-15
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Use of formycin B as a general substrate for measuring facilitated nucleoside transport in mammalian cells.
pubmed:affiliation
Department of Microbiology, Medical School, University of Minnesota, Minneapolis 55455.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.