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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
|
| pubmed:dateCreated |
1988-3-15
|
| pubmed:abstractText |
Binding experiments were performed with [3H]ouabain on plasma membranes derived from several types of isolated and cultivated endothelial cells. Identical saturation curves for [3H]ouabain binding to endothelial cells from pig aorta, caval vein, and pulmonary artery were obtained with a dissociation constant (KD) of 3.29 +/- 0.31 nmol/l and a binding capacity (Bmax) of 5.22 +/- 0.12 pmol/mg protein. On guinea-pig coronary endothelial cells, saturation of [3H]ouabain revealed much lower affinity (KD 95 +/- 15 nmol/l, Bmax 2.08 +/- 0.09 pmol/mg protein). All Scatchard plots were linear, indicating a homogeneous class of binding sites. In competition experiments, cardiac glycosides and their aglycons displaced the radioligand with a structure-activity relationship typical for interaction with Na+/K+-ATPase (proscillaridin A greater than ouabain greater than digoxin greater than g-strophanthidin greater than digoxigenin greater than dihydrodigoxin); in particular, removal of the sugar moiety results in considerable reduction of affinity. Furthermore, K+ displayed a steep inhibition curve with a half-maximal inhibitory constant of 2 mmol/l. All these findings suggest the presence of endothelial ouabain receptors linked to Na+/K+-ATPase. However, direct measurement of this enzyme was not possible due to an extremely high Mg2+-ATPase activity.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:issn |
0300-8428
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
82
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
544-50
|
| pubmed:dateRevised |
2007-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:2829813-Animals,
pubmed-meshheading:2829813-Binding Sites,
pubmed-meshheading:2829813-Cells, Cultured,
pubmed-meshheading:2829813-Endothelium, Vascular,
pubmed-meshheading:2829813-Guinea Pigs,
pubmed-meshheading:2829813-Ouabain,
pubmed-meshheading:2829813-Radioligand Assay,
pubmed-meshheading:2829813-Receptors, Drug,
pubmed-meshheading:2829813-Sodium-Potassium-Exchanging ATPase,
pubmed-meshheading:2829813-Swine
|
| pubmed:articleTitle |
Binding of [3H]ouabain to endothelial cells derived from various vascular beds.
|
| pubmed:affiliation |
Institute of Pharmacology, University of Vienna, Austria.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|