Nitric oxide inhibits thrombin receptor-activating peptide-induced phosphoinositide 3-kinase activity in human platelets

Alessio Pigazzi, Stanley Heydrick, Franco Folli, Stephen Benoit, Alan Michelson, Joseph Loscalzo

Research output: Contribution to journalArticlepeer-review

79 Scopus citations


Although nitric oxide (NO) has potent antiplatelet actions, the signaling pathways affected by NO in the platelet are poorly understood. Since NO can induce platelet disaggregation and phosphoinositide 3-kinase (PI3-kinase) activation renders aggregation irreversible, we tested the hypothesis that NO exerts its antiplatelet effects at least in part by inhibiting PI3-kinase. The results demonstrate that the NO donor S- nitrosoglutathione (S-NO-glutathione) inhibits the stimulation of PI3-kinase associated with tyrosine-phosphorylated proteins and of p85/PI3-kinase associated with the SRC family kinase member LYN following the exposure of platelets to thrombin receptor-activating peptide. The activation of LYN- associated PI3-kinase was unrelated to changes in the amount of PI3-kinase physically associated with LYN signaling complexes but did require the activation of LYN and other tyrosine kinases. The cyclic GMP-dependent kinase activator 8-bromo-cyclic GMP had similar effects on PI3-kinase activity, consistent with a model in which the cyclic nucleotide mediates the effects of NO. Additional studies showed that wortmannin and S-NO-glutathione have additive inhibitory effects on thrombin receptor-activating peptide-induced platelet aggregation and the surface expression of platelet activation markers. These data provide evidence of a distinct and novel mechanism for the inhibitory effects of NO on platelet function.

Original languageEnglish (US)
Pages (from-to)14368-14375
Number of pages8
JournalJournal of Biological Chemistry
Issue number20
StatePublished - May 14 1999
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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