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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
|
| pubmed:dateCreated |
1997-8-12
|
| pubmed:abstractText |
We have investigated the possible interaction (cross talk) between the phospholipase A2 (PLA2) and inositol 1,4,5-trisphosphate/protein kinase C (PKC) signaling pathways in rat lactotroph-enriched cell cultures. Melittin, a bee venom peptide, stimulated release of [3H]arachidonic acid ([3H]AA) from [3H]AA-labeled enriched lactotrophs in a dose-dependent manner. Moreover, melittin and exogenous AA induced a redistribution of PKC catalytic activity and PKC alpha and beta immunoreactivity from the soluble to the particulate fraction in resting and substance P (SP)-stimulated cells. Melittin had no effect on phospholipase C (PLC) activity. Pretreatment of cell cultures with the PLA2 inhibitors quinacrine and aristolochic acid resulted in a dose-dependent inhibition of melittin-stimulated PKC isozyme translocation as did the inhibitor of lipoxygenase, nordihydroguaiaretic acid, whereas the cyclooxygenase inhibitor indomethacin had no effect. SP and the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) dose-dependently increased levels of [3H]AA released from cells. Pretreatment of cell cultures with quinacrine reduced the effect of SP on [3H]AA formation. After long-term treatment (24 h) of cells with TPA, the effect of TPA on [3H]AA production was not different from control, whereas SP still displayed [3H]AA-releasing abilities although not at full scale. Pretreatment of cells with thapsigargin, U 73122, methoxyverapamil, and RHC 80267, an inhibitor of diacylglycerol lipase, all resulted in reduced SP-stimulated [3H]AA liberation. Treatment of cell cultures with pertussis toxin (PTX) reduced the release of [3H]AA induced by SP, whereas PTX had no effect on SP-stimulated generation of 3H-inositol phosphates. On the basis of these results, it is concluded that (1) the PLA2 pathways interfere with the phosphoinositide-PLC signaling system at the level of PKC isozymes alpha and beta, the product responsible for this interaction being either AA or a metabolite produced by the action of lipoxygenase; (2) SP and TPA are able to activate the PLA2 pathway at a level at or beyond PLA2, and this effect is mediated, in part, through PKC alpha and beta species and (for SP) intracellular Ca2+ recruited from internal stores as well as from external sources; and (3) SP also activates PLA2 through a PTX-sensitive pathway distinct from the one coupled to phosphoinositide-PLC, which is PTX insensitive.
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Arachidonic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Aristolochic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol 1,4,5-Trisphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes,
http://linkedlifedata.com/resource/pubmed/chemical/Melitten,
http://linkedlifedata.com/resource/pubmed/chemical/Phenanthrenes,
http://linkedlifedata.com/resource/pubmed/chemical/Phospholipases A,
http://linkedlifedata.com/resource/pubmed/chemical/Phospholipases A2,
http://linkedlifedata.com/resource/pubmed/chemical/Prolactin,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C,
http://linkedlifedata.com/resource/pubmed/chemical/Quinacrine,
http://linkedlifedata.com/resource/pubmed/chemical/Substance P,
http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate,
http://linkedlifedata.com/resource/pubmed/chemical/Tritium,
http://linkedlifedata.com/resource/pubmed/chemical/aristolochic acid I
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Aug
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| pubmed:issn |
0022-3042
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
69
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
762-72
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| pubmed:dateRevised |
2007-11-15
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| pubmed:meshHeading |
pubmed-meshheading:9231737-Animals,
pubmed-meshheading:9231737-Arachidonic Acid,
pubmed-meshheading:9231737-Aristolochic Acids,
pubmed-meshheading:9231737-Cells, Cultured,
pubmed-meshheading:9231737-Enzyme Inhibitors,
pubmed-meshheading:9231737-Female,
pubmed-meshheading:9231737-Inositol 1,4,5-Trisphosphate,
pubmed-meshheading:9231737-Isoenzymes,
pubmed-meshheading:9231737-Male,
pubmed-meshheading:9231737-Melitten,
pubmed-meshheading:9231737-Phenanthrenes,
pubmed-meshheading:9231737-Phospholipases A,
pubmed-meshheading:9231737-Phospholipases A2,
pubmed-meshheading:9231737-Pituitary Gland, Anterior,
pubmed-meshheading:9231737-Prolactin,
pubmed-meshheading:9231737-Protein Kinase C,
pubmed-meshheading:9231737-Quinacrine,
pubmed-meshheading:9231737-Rats,
pubmed-meshheading:9231737-Rats, Wistar,
pubmed-meshheading:9231737-Signal Transduction,
pubmed-meshheading:9231737-Substance P,
pubmed-meshheading:9231737-Tetradecanoylphorbol Acetate,
pubmed-meshheading:9231737-Tritium
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| pubmed:year |
1997
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| pubmed:articleTitle |
Cross talk between substance P and melittin-activated cellular signaling pathways in rat lactotroph-enriched cell cultures.
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| pubmed:affiliation |
Department of Physiology, Panum Institute, University of Copenhagen, Denmark.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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