title: Effects of suramin on human platelet aggregation and Ca2+ mobilization induced by thrombin and other agonists.
abstract: 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 microg/ml, respectively. Ca2+ mobilization induced by thrombin was inhibited by suramin with an approximate IC50 value of 20 microg/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.
authors.affiliation: Department of Chemistry, University of Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Siafaka-Kapadai
authors.forename: S
authors.initials: S
authors.lastname: Svetlov
authors.forename: D J
authors.initials: DJ
authors.lastname: Hanahan
authors.forename: M A
authors.initials: MA
authors.lastname: Javors
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000494:pharmacology; D001792:Blood Platelets / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D006801:Humans; D010712:Phosphatidic Acids / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013498:Suramin / Q000494:pharmacology*; D013917:Thrombin / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D010712:Phosphatidic Acids; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D016718:Arachidonic Acid; D013498:Suramin; D013917:Thrombin; D002118:Calcium