Linked Life Data

3979404

Source:http://linkedlifedata.com/resource/pubmed/id/3979404

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-4-26
pubmed:abstractText
Lipoprotein binding and metabolism in actively dividing (sparse) and quiescent (confluent) bovine aortic endothelial cells (EC) were compared quantitatively using 125I-labelled lipoproteins. The amounts of receptor-bound low density lipoproteins (LDL) decreased five- to ten-fold as the cultures progressed from sparse to confluent morphology. High affinity receptor-bound LDL levels were extremely low in confluent EC and accounted for the inability of confluent EC to internalize and degrade significant amounts of LDL. Conversely, the amounts of acetylated LDL (acLDL) bound and degraded via distinct sites increased at least five-fold during EC growth to confluence. LDL binding and metabolism in individual cells was assessed by fluorescence microscopy using 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labelled lipoproteins or fluorescein-conjugated antibodies. LDL and acLDL bound to the surfaces of sparse EC, at either 4 degrees or 37 degrees C, in a random distribution of fine punctate foci, contrary to a previous report. EC therefore appear to resemble fibroblasts in their distribution of surface LDL receptors. No binding or uptake of LDL was seen in confluent EC. Patterns of acLDL binding and uptake in confluent EC resembled those of LDL in sparse EC. Intracellular LDL and acLDL occurred as perinuclear accumulations of large fluorescent foci in sparse EC. Regeneration experiments were carried out in artificially wounded confluent cultures and renewed LDL receptor activity was shown in actively-dividing cells which had migrated into the "wounded" areas. We conclude that quiescent endothelial cells metabolize little LDL via the LDL-receptor pathway due to a drastically reduced number of receptors in confluent cells. This contrasts with the ability of confluent cells to metabolize relatively large amounts of acLDL via a receptor-mediated mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0171-9335
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
81-90
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Native and acetylated low density lipoprotein metabolism in proliferating and quiescent bovine endothelial cells in culture.
pubmed:publicationType
Journal Article