Linked Life Data

6290514

Source:http://linkedlifedata.com/resource/pubmed/id/6290514

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-12-21
pubmed:abstractText
The role of calcium in the release of superoxide anion (O2-) was examined in alveolar macrophages after stimulation with the soluble stimuli: concanavalin A (Con A), N-formyl methionyl phenylalanine (FMP), and the calcium ionophore. A23187. The release of O2- by Con A was unaffected over a wide range of extracellular calcium concentrations (20 microM to 3 mM), whereas increasing the extracellular calcium above 2 mM inhibited FMP-stimulated O2- release. In contrast, A23187 did not stimulate O2- release in calcium-free medium (less than or equal to 30 microM). The addition of EGTA (50 microM) to calcium-free medium had no effect on Con A stimulation of O2- release or FMP-stimulated O2- release. These results suggest that, for the three soluble stimuli, there are different roles for Ca+2 in the activation and transmission of stimulatory signals across the cell membrane. Con A- or FMP-stimulated calcium efflux from calcium-loaded cells in either calcium-free medium or 0.5 mM calcium-containing medium. In calcium-free medium, FMP transiently retarded 45Ca+2 uptake, while in 0.5 mM calcium-containing medium, FMP transiently stimulated 45Ca+2 uptake. For either Con A or FMP, calcium efflux preceded O2- release by 30-45 sec. Quinine, an agent that blocks membrane hyperpolarization in macrophages, completely blocked O2- release by concanavalin A or FMP and inhibited 45CA+2 efflux by 50% or more for both agents. These results support the hypothesis that redistribution of cellular Ca+2 is one of the initial steps leading to the release of O2-.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
113
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
87-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
The role of calcium in the initiation of superoxide release from alveolar macrophages.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.