INHIBITORY EFFECTS OF COPPER-ASPIRIN COMPLEX ON PLATELET-AGGREGATION

AIM: To study the inhibitory effects of copper-aspirin complex (CuAsp) on platelet aggregation. METHODS: With adenosine diphosphate the effe cts of CuAsp on platelet aggregation in vitro or in vivo, were investi gated. Radioimmunoassay and fluorophotometry were used to measure thro mboxane Bz (TXB2) generation from platelets, the levels of TXB2 and of 6-keto-PGF(1 alpha) in plasma and the platelet serotonin release reac tion. RESULTS: In vitro, CuAsp inhibited arachidonic acid (AA)-induced aggregation (IC50 = 17 mu mol.L-1, 95 % confidence limits: 9 - 33 mu mol.L-1), the release of 5-HT (IC50 = 19 mu mol.L-1, 95 % confidence l imits: 10 - 30 mu mol.L-1), and TXB2 generation from platelets (P < 0. 05). CuAsp 10 mg.kg(-1) ig selectively inhibited AA-induced aggregatio n, and increased the 6-keto-PGF(1 alpha) concentration in plasma while decreased that of TXB2. CONCLUSION: CuAsp, in vitro or in vivo, shows more potent inhibitory effects on AA-induced aggregation than aspirin (Asp), related to the inhibition of platelet cyclooxygenase and the r elease of active substances from platelets.