Linked Life Data

8048491

Source:http://linkedlifedata.com/resource/pubmed/id/8048491

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 1
pubmed:dateCreated
1994-8-30
pubmed:abstractText
Adenosine transport in cultured human umbilical vein endothelial cells (HUVEC) was characterized and shown to be mediated by a single facilitated diffusion mechanism. Initial rates of adenosine influx at 22 degrees C were saturable [apparent Michaelis constant, 69 +/- 10 microM; maximum velocity (Vmax), 600 +/- 70 pmol.10(6) cells-1.s-1] and inhibited by nitrobenzylthioinosine (NBMPR). Formycin B had an unusually high affinity [inhibitory constant (Ki), 18 +/- 4.3 microM], whereas inosine had a low affinity (Ki, 440 +/- 68 microM) and nucleobases were without effect on adenosine influx. The number of transporters (1.2 x 10(6) sites/cell) was estimated by NBMPR equilibrium binding (apparent dissociation constant, 0.11 +/- 0.01 nM; maximum binding, 2.0 +/- 0.15 pmol/10(6) cells). In addition, we compared these endothelial cells with those obtained from cords from pregnancies complicated by diabetes (HUVEC-D), since embriopathy may occur in these conditions. HUVEC-D exhibited a 2.3-fold reduction in both the Vmax for adenosine influx and the maximum number of NBMPR binding sites (260 +/- 40 pmol.10(6) cells-1.s-1 and 0.86 +/- 0.08 pmol/10(6) cells, respectively). However, the turnover number for each nucleoside transporter in normal and diabetic HUVEC was similar (approximately 300 adenosine molecules/s). Adenosine metabolism at 10 microM in HUVEC-D was modified compared with normal cells. Intracellular phosphorylation (> 90%) was the predominant pathway in normal HUVEC, whereas in HUVEC-D, substantial levels of adenine and adenosine were detected. The present results demonstrate therefore the downregulation of the NBMPR-sensitive nucleoside transporter and changes in adenosine metabolism in HUVEC from diabetic pregnancies.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C39-47
pubmed:dateRevised
2009-9-29
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Adenosine transport in cultured human umbilical vein endothelial cells is reduced in diabetes.
pubmed:affiliation
Department of Physiology and Biophysics, University of Chile, Santiago.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't