Linked Life Data

2357730

Source:http://linkedlifedata.com/resource/pubmed/id/2357730

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-8-2
pubmed:abstractText
We have studied the effects of prostaglandin E2 (PGE2) and cholera toxin, two modulators of adenylyl cyclase, and 8-bromo cAMP (8-BrcAMP) on various parameters of lymphocyte activation using the human T cell line Jurkat. Our results show that PGE2 and cholera toxin inhibit, in a dose-related manner, the phytohemagglutinin (PHA)-dependent production of interleukin 2 by these cells. The data are consistent with the interpretation that the inhibition is due to an intracellular increase in cAMP, since the metabolically stable 8-BrcAMP analog produced the same inhibitory effect. However, PGE2 or 8-BrcAMP did not interfere with the PHA-induced elevation in the cytosolic concentration of Ca2+, suggesting that changes in the intracellular concentration of cAMP does not affect the internal release or the influx of Ca2+. In contrast, cholera toxin prevented the Ca2+ response of Jurkat cells to PHA. We studied the effects of PGE2, cholera toxin, and 8-BrcAMP on the amplitude of the K+ outward current using the patch clamp technique in the whole cell configuration. Results showed that PGE2, 8-BrcAMP, and cholera toxin inhibited K+ channel activity. For instance, the amplitude of the outward K+ current was reduced to 43 +/- 19%, 50 +/- 26%, and 46 +/- 16% of control values in the case of cells perfused in the presence of PGE2, 8-BrcAMP, and cholera toxin, respectively. Blocking K+ channels with tetraethylammonium ions did not prevent the characteristic Jurkat Ca2+ response to PHA. Our observations that cAMP inhibits K+ channel activity in a T cell line provide an additional explanation for its reported inhibition of lymphocyte activation. Increasing the intracellular concentration of cAMP may result in reduction of K+ movements and in negative modulation of signal transduction via G-proteins as previously suggested. These two effects could act in synergy to impair signal transduction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0008-8749
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
385-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Effects of modulators of adenylyl cyclase on interleukin-2 production, cytosolic Ca2+ elevation, and K+ channel activity in Jurkat T cells.
pubmed:affiliation
Department of Biochemistry, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't