Linked Life Data

12527368

Source:http://linkedlifedata.com/resource/pubmed/id/12527368

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-3
pubmed:dateCreated
2003-1-15
pubmed:abstractText
Receptor-mediated production of inositol 1,4,5-trisphosphate (InsP(3)) initiates Ca(2+) release and is responsible for cytosolic Ca(2+) oscillations. InsP(3) oscillations have also been observed in some cells. One of the enzymes controlling InsP(3) catabolism, the InsP(3) 3-kinase, is stimulated by Ca(2+); this regulation is presumably part of the reason for InsP(3) oscillations that have been observed in some cells. Here, we investigate the possible role of Ca(2+)-activated InsP(3) catabolism on the characteristics of the InsP(3)-induced Ca(2+) oscillations. Numerical simulations show that if it is assumed that the Ca(2+)-independent InsP(3) catabolism is predominant, Ca(2+) oscillations remain qualitatively unchanged although the relative amplitude of the oscillations in InsP(3) concentrations becomes minimal. We tested this prediction in hepatocytes by masking the Ca(2+)-dependent InsP(3) catabolism by 3-kinase through the injection of massive amounts of InsP(3) 5-phosphatase, which is not stimulated by Ca(2+). We find that in such injected hepatocytes, Ca(2+) oscillations generated by modest agonist levels are suppressed, presumably because of the decreased dose in InsP(3), but that at higher doses of agonist, oscillations reappear, with characteristics similar to those of untreated cells at low agonist doses. Altogether, these results suggest that oscillations in InsP(3) concentration due to Ca(2+)-stimulated InsP(3) catabolism do not play a major role for the oscillations in Ca(2+) concentration.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
534
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
101-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Ca2+ oscillations in hepatocytes do not require the modulation of InsP3 3-kinase activity by Ca2+.
pubmed:affiliation
Université Libre de Bruxelles, Faculté des Sciences CP231, Boulevard du Triomphe, B-1050 Brussels, Belgium. gdupont@ulb.ac.be
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't