The purpose of this study was to investigate the effect of suramin, a polyanionic napthalene sulfonic acid, on human platelet aggregation and Ca2+ mobilization induced by various agonists. Our results show that suramin completely inhibited aggregation by thrombin, platelet activating factor (PAF), alkyllysophosphatidic acid (ALPA), or arachidonic acid in a concentration-dependent manner. The IC50 values of suramin for inhibition of aggregation by PAF, arachidonic acid, and thrombin were 76.7, 239, and 1.49 μg/ml, respectively. Ca2+ mobilization induced by thrombin was inhibited by suramin with an approximate IC50 value of 20 μg/ml. This concentration of suramin had no effect on PAF or oleic acid-induced Ca2+ mobilization. The mechanism by which suramin inhibits aggregation is not clear, but our results suggest that suramin inhibits the ligand-receptor interaction.
- Arachidonic acid
- Ca mobilization
- Platelet aggregation
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)