Linked Life Data

2982888

Source:http://linkedlifedata.com/resource/pubmed/id/2982888

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-4-15
pubmed:abstractText
Stimulation by the tripeptide N-formyl norleucyl leucyl phenylalanine (FNLLP) of the guinea pig alveolar macrophage gives rise to transient production of superoxide anion (O2-). Components of the phosphatidyl inositol (PI) cycle (phosphatidic acid (PA), phosphatidyl inositol-4,5-bisphosphate (TPI) and phosphatidyl inositol-4-phosphate (DPI) were monitored using 32P in order to examine the possible association of this cycle with the FNLLP-stimulated production of O2-. Macrophage stimulation by FNLLP led to an increased flux of metabolites through the PI cycle. The level of 32P label in both TPI and DPI rapidly decreased upon exposure to FNLLP, followed by a 5-min period during which the 32P label in TPI and DPI approached prestimulated levels. During this period, there was a fivefold increase in 32P-PA. It is suggested that diacylglycerol (DAG) is the O2- -activating intermediate in the stimulated mechanism, as evidenced by the buildup of PA (for which DAG is the precursor) in parallel with the time course of O2- production. The importance of continued cycling of PI in the stimulated mechanism is demonstrated by the inhibition by LiCl of the extent, but not the initial rate, of both O2- production and the formation of 32P-PA upon peptide stimulation after 1-h preincubation with 10 mM LiCl. The influence of calcium on this mechanism was also examined. It has previously been demonstrated that intracellular availability of calcium can influence the rate and extent of O2- production. In cells preloaded with quin-2, which acts as a high-affinity sink for calcium in the cytosol, the initial rate of FNLLP-stimulated O2- production is inhibited in low (10 microM) extracellular calcium medium. High extracellular calcium (1 mM) completely reverses this inhibition and also significantly extends the time course of O2- production in both quin-2 and control cells (Stickle et al., 1984). In parallel with these effects on O2- production, varying calcium conditions is demonstrated to influence the rate and extent of PA formation. These same calcium conditions were found to have little or no effect on the initial unstimulated levels of TPI, DPI, and PA. These results indicate that the influence of an intracellular pool of calcium on O2- production may be via its influence on stimulated PI turnover.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Chlorides, http://linkedlifedata.com/resource/pubmed/chemical/Lithium, http://linkedlifedata.com/resource/pubmed/chemical/Lithium Chloride, http://linkedlifedata.com/resource/pubmed/chemical/N-formylnorleucyl-leucyl-4-phenylala..., http://linkedlifedata.com/resource/pubmed/chemical/Oligopeptides, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol 4,5-Diphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositol Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositols, http://linkedlifedata.com/resource/pubmed/chemical/Superoxides, http://linkedlifedata.com/resource/pubmed/chemical/phosphatidylinositol 4-phosphate
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
123
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
39-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Calcium regulation of phosphatidyl inositol turnover in macrophage activation by formyl peptides.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.