Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-2-10
pubmed:abstractText
Platelet-activating factor (PAF) elicited an increase in intracellular Ca2+ concentration, [Ca2+]i, in neuroblastoma x glioma hybrid NG 108-15 cells as measured by fura-2 fluorescence method. The rise in [Ca2+]i was primarily due to the influx of Ca2+ from extracellular source. Preincubation of cells with the Ca(2+)-ion channel blockers, including verapamil, nifedipine and conotoxin, did not affect the Ca(2+)-response stimulated by PAF, indicating that the PAF-elicited Ca(2+)-influx is not mediated through the classical voltage-dependent Ca(2+)-ion channels. In contrast, SK&F 96365, which is an inhibitor of receptor-operated calcium channel, blocked the PAF-elicited Ca(2+)-response dose-dependently. When cells were pretreated with the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA), PAF-elicited Ca(2+)-signal was diminished substantially. In contrast, the protein kinase A activator, forskolin, has no effect on the Ca(2+)-response induced by PAF. Further experiment demonstrated that genistein, an inhibitor of tyrosine kinase, also caused inhibition on PAF-induced Ca(2+)-response significantly. There results suggest that the PAF receptor-coupled Ca(2+)-ion channel is subjected to the modulation by protein kinase C and tyrosine-specific kinase. Pretreatment of cells with PAF resulted in the desensitization of the Ca(2+)-response following further stimulation with the same agonist. The heterologous desensitization of the PAF-induced Ca2+ influx was also observed in cells pretreated with bradykinin or to a less extent with ATP. Conversely, pretreatment of cells with PAF affected only partially the Ca(2+)-response elicited by bradykinin or ATP. Additive response was observed when PAF and ATP were added together but not PAF and bradykinin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0304-4920
pubmed:author
pubmed:issnType
Print
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
57-63
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Platelet-activating factor receptor-mediated calcium influx in NG 108-15 cells.
pubmed:affiliation
Division of Cardiovascular Research, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't