Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 6
pubmed:dateCreated
2005-3-14
pubmed:abstractText
Osmotic erythrocyte shrinkage leads to activation of cation channels with subsequent Ca2+ entry and stimulates a sphingomyelinase with subsequent formation of ceramide. Ca2+ and ceramide then activate a scramblase leading to breakdown of phosphatidylserine asymmetry of the cell membrane. The mediators accounting for activation of erythrocyte sphingomyelinase and phosphatidylserine exposure remained elusive. The study demonstrates that platelet-activating factor (PAF) is released from erythrocytes upon hyperosmotic cell shrinkage. The experiments further disclose the presence of PAF receptors in erythrocytes and show that PAF stimulates the breakdown of sphingomyelin and the release of ceramide from erythrocytes at isotonic conditions. PAF further triggers cell shrinkage (decrease of forward scatter) and phosphatidylserine exposure (annexin binding) of erythrocytes. The stimulation of annexin-binding is blunted by a genetic knockout of PAF receptors, by the PAF receptor antagonist ABT491 or by inhibition of sphingomyelinase with urea. In conclusion, PAF activates an erythrocyte sphingomyelinase and the then formed ceramide leads to the activation of scramblase with subsequent phosphatidylserine exposure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1233-43
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15741229-Annexins, pubmed-meshheading:15741229-Apoptosis, pubmed-meshheading:15741229-Blood Platelets, pubmed-meshheading:15741229-Blotting, Western, pubmed-meshheading:15741229-Calcium, pubmed-meshheading:15741229-Cell Separation, pubmed-meshheading:15741229-Ceramides, pubmed-meshheading:15741229-Cytosol, pubmed-meshheading:15741229-Detergents, pubmed-meshheading:15741229-Dose-Response Relationship, Drug, pubmed-meshheading:15741229-Erythrocyte Membrane, pubmed-meshheading:15741229-Erythrocytes, pubmed-meshheading:15741229-Flow Cytometry, pubmed-meshheading:15741229-Humans, pubmed-meshheading:15741229-Leukocytes, pubmed-meshheading:15741229-Octoxynol, pubmed-meshheading:15741229-Phosphatidylserines, pubmed-meshheading:15741229-Platelet Activating Factor, pubmed-meshheading:15741229-Platelet Membrane Glycoproteins, pubmed-meshheading:15741229-Receptors, G-Protein-Coupled, pubmed-meshheading:15741229-Sphingomyelin Phosphodiesterase, pubmed-meshheading:15741229-Temperature, pubmed-meshheading:15741229-Time Factors
pubmed:year
2005
pubmed:articleTitle
Stimulation of erythrocyte ceramide formation by platelet-activating factor.
pubmed:affiliation
Department of Physiology, University of Tübingen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't