Linked Life Data

2350587

Source:http://linkedlifedata.com/resource/pubmed/id/2350587

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-7-17
pubmed:abstractText
Exposure of blood platelets to foreign surfaces or to potent agonists in suspension results in dramatic changes in physical appearance and conversion from a nonsticky state. The transformation to the sticky state is associated with exposure of the fibrinogen receptor, GPIIB-IIIa, which is hidden in resting, discoid platelets. Recent studies employing fibrinogen coupled to gold (Fgn-Au) as an electron-dense probe have suggested that GPIIb-IIIa receptors not only become exposed in surface-activated platelets, but undergo a reorganization not observed in suspension-activated cells. Discoid platelets do not bind Fgn-Au; however, the bodies and extended pseudopods of dendritic forms are covered with Fgn-Au particles. Conversion of dendritic platelets to spread forms is accompanied by movement of receptor-ligand complexes away from peripheral margins into a concentrated mass in cell centers over the inner filamentous zone of the cytoplasm. Movement of the Fgn-Au particles to cell centers during spreading was considered due to the transmembrane action of the newly assembled actin filaments. We have carried out similar experiments on surface- and suspension-activated platelets with Fgn-Au and latex particles. GPIIb-IIIa receptors move Fgn-Au particles on outer membranes of surface- and suspension-activated platelets to channels of the open canalicular system. Treatment with cytochalasin B prevents assembly of actin filaments in surface- and suspension-activated platelets, and dissociates residual actin from the cell membranes, circumferential microtubules and organelles with which they interact. However, cytochalasin B does not prevent removal of Fgn-Au to channels of the open canalicular system. Thus, reorganization of fibrinogen receptors on surface- and suspension-activated platelets is due to the particles, and not to the fibrinogen, although fibrinogen is required to link gold to the receptor. The surface membrane has its own detergent and cytochalasin B-resistant cytoskeleton for directed transport of ligand-receptor complexes, independent of the internal assembly and contraction of actin into an inner filamentous zone.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0340-4684
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-70; discussion 70-2
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Platelet membrane responses to surface and suspension activation.
pubmed:affiliation
Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis 55455.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't