Linked Life Data

12787872

Source:http://linkedlifedata.com/resource/pubmed/id/12787872

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2003-6-5
pubmed:abstractText
N-Ethylmaleimide (NEM), a thio-alkylating agent, concentration-dependently stimulated the elevation of [Ca(2+)](i) in rat neutrophils in the presence of external Ca(2+). This effect was not observed in Ca(2+)-free medium and was abrogated by dithiothreitol pretreatment. The application of NEM after cyclopiazonic acid (CPA) stimulated the store-emptying activation of Ca(2+) entry. Unlike CPA-induced cation entry, NEM showed poor uptake of Ba(2+) and Sr(2+) and did not induce Mn(2+) influx. NEM diminished CPA-induced Mn(2+) influx, an effect that was blocked by dithiothreitol. Both Ni(2+) and La(3+) attenuated the elevation of [Ca(2+)](i) in response to NEM; however, greater resistance was observed to Ni(2+) inhibition of NEM-induced Ca(2+) influx than inhibition of store-operated Ca(2+) entry. Both cis-N-(2-phenylcyclopentyl)azacyclotridec-1-en-2-amine (MDL-12,330A) and 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole (SKF-96365), Ca(2+) channel blockers, and calyculin A, an inhibitor of protein serine/threonine phosphatases 1/2, diminished the NEM-induced Ca(2+) entry. Treatment of cells with genistein, a general tyrosine kinase inhibitor, or with wortmannin and 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), phosphatidylinositol 3-kinase inhibitors, had no appreciable inhibitory effects on the action of NEM. However, 2-aminoethyldiphenyl borate, an inositol trisphosphate receptor antagonist, enhanced rather than inhibited the [Ca(2+)](i) change in response to NEM. These results indicate that NEM stimulates Ca(2+) entry and regulates Ca(2+) signaling through direct thiol oxidation, bypassing the cellular signal transduction pathway. The NEM-regulated Ca(2+) signal demonstrates characteristics that distinguish it from the store-emptying operation in neutrophils, and therefore represents two distinct modes of Ca(2+) regulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2952
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1923-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Characterization of maleimide-activated Ca2+ entry in neutrophils.
pubmed:affiliation
Department of Education and Research, Taichung Veterans General Hospital, 160, Chung Kang Road, Sec. 3, Taiwan, Republic of China. w1994@vghtc.vghtc.gov.tw
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't