Aurin tricarboxylic acid inhibits adhesion of platelets to subendothelium.
Aurin-tricarboxylic acid (ATA) is a polycarboxylated compound which binds to high molecular weight multimers of von Willebrand factor (vWf), effectively preventing binding of vWf to platelet membrane GPIb. By this mechanism, ATA inhibits shear-induced platelet aggregation as well as ristocetin-induced platelet aggregation/agglutination, both of which require interaction of platelets and vWf. Although it is reasonable to assume that ATA might also interfere with platelet adhesion, the effects of ATA on this aspect of platelet function have not been described. We report effects of ATA on adhesion of freshly prepared radiolabeled platelets to subendothelium of everted rabbit aorta utilizing a model which permits observations at varying shear rates. Using concentrations of ATA that inhibited aggregation induced by either ristocetin or the more potent agonist, thrombin, ATA was found to inhibit adhesion of platelets in a dose-dependent manner. In addition, ATA was found to inhibit platelet aggregation in response to the agonists ristocetin or thrombin. The inhibitory effect of ATA on thrombin-induced aggregation was completely erased by washing and resuspension in a thrombin-free medium, indicating that ATA does not have any lasting effects on the platelet response to thrombin. In plasma coagulation tests, using either the prothrombin time, activated partial thromboplastin time of thrombin time, ATA prolonged clotting times in a dose-dependent manner.
Owens
M R
MR
Hematology and Oncology Consultants of Tidewater, Norfolk, Virginia 23510, USA.
Holme
S
S
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects; D001312:Aurintricarboxylic Acid / Q000494:pharmacology*; D001780:Blood Coagulation Tests; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010973:Platelet Adhesiveness / Q000187:drug effects*; D011817:Rabbits
D001312:Aurintricarboxylic Acid