Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1989-11-1
pubmed:abstractText
1. Nutrient transport in cultured human umbilical vein endothelial cells was characterized using a rapid dual-isotope dilution technique. Microcarrier beads with confluent endothelial cells were perfused in small columns, and uptake and efflux were assessed relative to D-mannitol (extracellular tracer) during a single transit through the column. 2. At tracer concentrations significant unidirectional uptakes were measured for L-leucine (53 +/- 2%), L-phenylalanine (73 +/- 2%), L-serine (40 +/- 4%), L-arginine (42 +/- 3%) and L-ornithine (26 +/- 3%). Uptake for L-proline, D-glucose, dopamine and serotonin was lower (6-10%), whereas uptake for the system A analogue 2-methylaminoisobutyric acid (2-MeAIB) was negligible. Uptakes rapidly decreased with time due to tracer efflux. 3. Endothelial cell transport of L-leucine was markedly inhibited during perfusion with 1 mM-BCH (beta-2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid, system L analogue), L-leucine, D-leucine, L-phenylalanine, L-methionine and L-DOPA. 2-MeAIB, L-cysteine, glycine, L-proline, hydroxy-L-proline, L-aspartate and beta-alanine were poor inhibitors, while L-serine and the cationic substrates L-lysine and L-arginine inhibited uptake by 10-35%. 4. When the kinetics of L-leucine transport were examined over a wide range of substrate concentrations (0.025-1 mM) transport was saturable. A single entry site analysis gave a half-maximal saturation constant Kt = 0.24 +/- 0.08 mM (mean +/- S.E.M., n = 5) and a Vmax = 27.8 +/- 4.6 nmol/min per column (approximately 3 x 10(6) cells). 5. Removal of sodium from the perfusate inhibited tracer uptake of L-leucine, L-serine and L-arginine by respectively 20 +/- 5% (n = 3), 77 +/- 5% (n = 3) and 35 +/- 4% (n = 3). 6. Our results provide the first evidence that cultured human endothelial cells of venous origin express a saturable transport system for large neutral amino acids resembling system L described in brain microvascular endothelium. Detection of Na+-dependent and Na+-independent L-arginine uptake is of interest in view of recent reports that this cationic amino acid may be the physiological precursor for nitric oxide released by endothelium.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-1090191, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-1206400, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-2871806, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-2890711, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3010815, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3013078, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3023320, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3082360, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3087423, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3110421, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3285141, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3378578, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3390182, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3495737, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3518617, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3539629, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3552706, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3668544, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3681732, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-3897465, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-4355998, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-4580109, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-5044755, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6131110, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6260823, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6339562, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6361813, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6415116, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6707951, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6749382, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6754458, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6807101, http://linkedlifedata.com/resource/pubmed/commentcorrection/2677320-6990271
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3751
pubmed:author
pubmed:issnType
Print
pubmed:volume
410
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
325-39
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Expression of amino acid transport systems in cultured human umbilical vein endothelial cells.
pubmed:affiliation
Department of Physiology, King's College, London.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't