title: Okadaic acid and vanadate inhibit collagen-induced platelet aggregation; the functional relation of phosphatases on platelet aggregation.
abstract: The different specific inhibitors for phosphoserine/threonine and phosphotyrosine protein phosphatases were used to study the role of these protein phosphatases in collagen-platelet interaction. The collagen-induced platelet aggregation and the release reaction as measured ATP release were inhibited in a dose-dependent fashion by the addition of okadaic acid, a specific inhibitor of phosphoserine/threonine protein phosphatase 1 and 2A. The inhibition was also observed by the addition of a phosphotyrosine protein phosphatase inhibitor, vanadate. Suboptimal concentrations of both inhibitors together also inhibited collagen-induced platelet aggregation and release reaction in a concentration-dependent fashion. These results suggest that collagen-platelet interaction is modulated by both protein phosphatases.
authors.affiliation: Veterans Affairs Medical Center, Memphis, TN.
authors.forename: T M
authors.initials: TM
authors.lastname: Chiang
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D003094:Collagen / Q000037:antagonists & inhibitors*; D003864:Depression, Chemical; D004988:Ethers, Cyclic / Q000494:pharmacology*; D006801:Humans; D019319:Okadaic Acid; D010749:Phosphoprotein Phosphatases / Q000502:physiology*; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology*; D010768:Phosphoserine / Q000378:metabolism; D019000:Phosphotyrosine; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D054645:Protein Phosphatase 1; D012701:Serotonin / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology*
chemical_list: D004988:Ethers, Cyclic; D010975:Platelet Aggregation Inhibitors; D010768:Phosphoserine; D019319:Okadaic Acid; D019000:Phosphotyrosine; D012701:Serotonin; D014638:Vanadates; D014443:Tyrosine; D000255:Adenosine Triphosphate; D003094:Collagen; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D010744:Phosphoric Monoester Hydrolases; C022394:phosphoserine phosphatase