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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1992-3-12
pubmed:abstractText
We have shown that platelet-activating factor (PAF) primes neutrophil (PMN) responses and enhances their ability to damage endothelial cells. Furthermore, thrombin-stimulated endothelial cells which produce PAF can augment and prime PMN superoxide production, elastase release and adhesion to endothelium. We wondered whether these marginated neutrophils (PMN) themselves, or their release products, might feedback and further amplify endothelial cell activation. To measure cellular activation, we assessed changes in endothelial cell intracellular calcium [( Ca2+]i) in endothelial monolayers loaded with Fura-2, and PAF production by [3H]acetate incorporation into phospholipid. Resting PMNs induced no change in [Ca2+]i, while N-formyl-L-methionine-L-leucyl-L-phenylalanine stimulated PMN and their lysosomal products caused a 25% increase in endothelial cell calcium. Sonicates of PMN produced a much larger increase in [Ca2+]i than activated PMN; the effect of PMN sonicates could in part be reduced by the serine protease inhibitor, alpha 1 antitrypsin. In contrast, purified neutrophil elastase did not alter endothelial cell [Ca2+]i. Despite hydrogen peroxide's ability to increase [Ca2+]i, catalase failed to inhibit the PMN-induced rise in [Ca2+]i. Since polyanionic heparin inhibited the PMN sonicate rise in calcium, a cationic protein released by PMN was thought to be responsible. The cationic primary granule enzyme, cathepsin G, duplicates the rise in [Ca2+]i seen with PMN sonicates. Furthermore, PAF production increased threefold in response to neutrophil sonicates. Thus, during inflammation, when coagulation and inflammatory cells are activated the endothelium responds by priming PMNs and promoting margination.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0921-8319
pubmed:author
pubmed:issnType
Print
pubmed:volume
2 Suppl
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
S23-30
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Endothelial cell platelet-activating factor primes neutrophil responses: amplification of endothelial activation by neutrophil products.
pubmed:affiliation
Department of Medicine, University of Minnesota, Minneapolis.
pubmed:publicationType
Journal Article