Enhancement of collagen-induced phosphoinositide turnover by thromboxane A2 analogue through Ca2+ mobilization in human platelets

Kozo Kaibuchi, Terutaka Tsuda, Akira Kikuchi, Tetsuji Tanimoto, Yoshimi Takai

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)


In human washed platelets, collagen-induced phosphoinositide turnover was inhibited by indomethacin, an inhibitor of thromboxane A2 (TXA2) formation, particularly at lower doses of collagen. This inhibition was counteracted by the addition of 9,11-epithio-11,12-methano-TXA2 (STA2), a stable analogue of TXA2 as well as by the Ca2+ ionophore A23187. STA2 and A23187 did not stimulate phosphoinositide turnover markedly, but significantly increased cytoplasmic free Ca2+ concentrations. The actions of STA2 were blocked by 13-azaprostanoic acid, a TXA2 receptor antagonist. These results suggest that TXA2 is generated during the action of collagen and increases cytoplasmic free Ca2+ which then stimulates phosphoinositide turnover in cooperation with collagen.

Original languageEnglish
Pages (from-to)104-108
Number of pages5
JournalFEBS Letters
Issue number1
Publication statusPublished - 11-11-1985
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology


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