Investigation on Adenosine Diphosphate (ADP) Induced Platelet Adhesiveness in Vitro Part III. The Inactivation of ADP in Plasma

Abstract

SummaryThe results of investigations on the ADP inactivating system in platelet poor plasma are given. The activity of the system is maximal at about 37° C. and is irreversibly destroyed by heating for 15 minutes at 58° C. The system is non dialysable and is inactivated by KCN, cysteine, 2.3-dimercaptopropanole (BAL) and penicillamine at concentrations between 2 · 10∼3 and 5 · 10−3M.The ADP inactivating ability of platelet poor plasma from normals, patients with thyrotoxicosis, diabetes mellitus, hypercholesterolemia and some patients with bleeding disorders has been estimated. The inactivation by plasma from patients with thyrotoxicosis is markedly increased as compared with the other groups. A possible relationship between the low frequency of thromboembolism and the increased ADP degradation in these patients is discussed.