Oleic acid-induced Ca2+ mobilization in human platelets: Is oleic acid an intracellular messenger?

Athanassia Siafaka-Kapadai, Donald J. Hanahan, Martin A. Javors

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

The purpose of this study was to explore the effect of oleic acid (OA) on intracellular Ca2+ mobilization in human platelets. When applied extracellularly, OA produced a concentration dependent rise in cytosolic [Ca2+] ([Ca2+](cyt)) when extracellular [Ca2+] ([Ca2+](ext) was zero (presence of EGTA), suggesting that OA caused an intracellular release of Ca2+. Intracellular Ca2+ release was directly proportional to entry of OA into platelets and OA entry was indirectly proportional to [Ca2+](ext). In permeabilized platelets, OA caused the release of 45Ca2+ from ATP dependent intracellular stores. Finally, our results show that thrombin stimulated the release of [3H]OA from platelet phospholipids. The saturated fatty acids stearic and palmitic acid did not stimulate an increase in [Ca2+](cyt) under these conditions, but the unsaturated fatty acid, linolenic acid produced effects similar to those of OA, suggesting specificity among fatty acids for effects on [Ca2+](cyt). Taken together, our experiments suggest that OA which has been incorporated into platelet phospholipids was released into the cytosol by thrombin stimulation. Our experiments also show that OA stimulates Ca2+ release from intracellular stores. These results support the hypothesis that OA may serve as an intracellular messenger in human platelets.

Original languageEnglish (US)
Pages (from-to)215-232
Number of pages18
JournalJournal of Lipid Mediators and Cell Signalling
Volume15
Issue number3
DOIs
StatePublished - Mar 1 1997

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Keywords

  • Ca mobilization
  • Human platelets
  • Intracellular lipid messenger
  • Oleic acid
  • Thrombin

ASJC Scopus subject areas

  • Immunology
  • Pharmacology

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