Linked Life Data

7840141

Source:http://linkedlifedata.com/resource/pubmed/id/7840141

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1 Pt 1
pubmed:dateCreated
1995-2-28
pubmed:abstractText
We have demonstrated that phospolipase A2 (PLA2) activation in human neutrophils requires both the influx of extracellular Ca2+ and leukotriene B4 (LTB4). Surprisingly, the eicosanoids (LTB4 and its omega-oxidation products) formed were quantitatively very similar in both thapsigargin (Thap)- and A-23187-stimulated neutrophils. In contrast, Thap had very little effect on the activation of PLA2 when 5-lipoxygenase (5-LO) was blocked by BW755C or MK-886, whereas A-23187 caused a substantial activation. The lack of PLA2 activation in Thap-stimulated neutrophils results from the inhibition of LTB4 formation in the presence of 5-LO inhibitors. It appears that A-23187 activates both LTB4-dependent and -independent PLA2, whereas Thap activates LTB4-dependent PLA2. Experiments with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid demonstrated that activation of Thap-sensitive PLA2 and 5-LO requires the influx of Ca2+. Neither the transient elevation of cytosolic Ca2+ from intracellular stores nor the sustained Ca2+ influx alone without LTB4 appears sufficient to cause the activation of LTB4-dependent PLA2. We suggest that the activation of LTB4-dependent PLA2 involves 1) a sustained elevation of cytosolic Ca2+ coupled to the influx of extracellular Ca2+ and 2) a coupling between LTB4 and its receptor. We conclude that LTB4-dependent PLA2 plays an important role in the poststimulatory formation of lipid mediators such as prostaglandins, leukotrienes, and platelet-activating factor.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C138-46
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Phospholipase A2 activation in human neutrophils requires influx of extracellular Ca2+ and leukotriene B4.
pubmed:affiliation
Department of Foods and Nutrition University of Manitoba, Winnipeg, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't