Linked Life Data

7803236

Source:http://linkedlifedata.com/resource/pubmed/id/7803236

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-1-30
pubmed:abstractText
Down-regulation and clearance of as many as 60-80% of GPIb/IX receptors from exposed surfaces on thrombin-activated platelets to channels of the open canalicular system (OCS) is considered to be a fundamental mechanism regulating platelet adhesivity in vitro and in vivo. The present study has combined thrombin stimulation in suspension, surface activation on formvar grids, receptor occupancy by von Willebrand factor (vWF) and exposure to anti-vWF antibody in an effort to demonstrate the removal of GPIb/IX receptors from activated cells. Individually the stimuli failed to cause any change in the frequency of GPIb/IX receptors. Combined, the stimuli were no more effective than when each was used alone. The only way to cause GPIb/IX to move was to add anti-vWF to thrombin-activated platelets allowed to spread on formvar grids and covered with multimers of ristocetin-activated human or bovine vWF. Translocation of GPIb/IX-vWF-anti-vWF complexes from peripheral margins into caps over cell centres, however, did not clear the peripheral zone of vWF binding capacity. Exposure of capped platelets after fixation to a second incubation with vWF demonstrated as many multimers extending from the central cap to the peripheral margins as were seen on platelets exposed a single time to vWF. Antibodies to GPIb, but not to GPIIb/IIIA, prevented the second labelling by vWF. Down-regulation or clearance of GPIb/IX, in light of this study, does not appear to be a fundamental mechanism modulating platelet adhesivity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0007-1048
pubmed:author
pubmed:issnType
Print
pubmed:volume
88
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
137-48
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Influence of combined thrombin stimulation, surface activation, and receptor occupancy on organization of GPIb/IX receptors on human platelets.
pubmed:affiliation
Department of Laboratory Medicine, University of Minnesota Medical School, Minneapolis 55455.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't