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Binding of heparin and low molecular weight heparin fragments to human vascular endothelial cells in culture.

Authors :
Bârzu T
Molho P
Tobelem G
Petitou M
Caen JP
Source :
Nouvelle revue francaise d'hematologie [Nouv Rev Fr Hematol (1978)] 1984; Vol. 26 (4), pp. 243-7.
Publication Year :
1984

Abstract

The interaction of standard heparin and some low molecular weight heparin fragments (CY 222, mw 1,500-8,000 daltons) with human vascular endothelium in culture was studied using both 125I and 3H labeled ligands. A specific and saturable binding was shown for both labeled standard heparins. Two populations of binding sites for 3H-standard heparin could be distinguished: one of high affinity (KD = 0.12 microM), and another of lower affinity (KD = 1.37 microM). Total binding capacity was in the order of 10(7) molecules per cell. The same high level of affinity was calculated for unlabeled compounds from competition experiments with 125I-standard heparin. No other glycosaminoglycans, except a highly sulfated heparan (fraction IIA) could compete for heparin binding sites. A specific binding was also shown for 125I-CY 222. The affinity of unlabeled CY 222 was approximately ten times lower than that of unfractionated heparin. However, CY 222 could compete for approximatively 30% of standard heparin binding. Binding was not completely reversible. Even in the presence of a large excess of unlabeled compounds, a fraction of 25% of radioactive heparins remained bound to the endothelium. This fraction was three times lower if incubation was carried out at +4 degrees C, suggesting a possible incorporation of heparin into the endothelial cells.

Details

Language :
English
Volume :
26
Issue :
4
Database :
MEDLINE
Journal :
Nouvelle revue francaise d'hematologie
Publication Type :
Academic Journal
Accession number :
6473094