Effects of copper-aspirin complex on plasma 6-keto-prostaglandin F-1 alphalevel and platelet cytosolic calcium in rabbits

Effects of copper-aspirin complex on washed platelet aggregation, thromboxa ne B-2 formation and 6-keto-prostaglandin F-1 alpha level were monitored by Born's and Terashita's methods, respectively. The influence of copper-aspi rin complex on cytosolic free calcium was examined using the fluorescent in dicator, Fura 2-AM. Copper-aspirin complex significantly inhibited arachido nic acid-induced aggregation in washed platelets. The IC50 value was 9.6 mu mol L-1. Copper-aspirin complex significantly decreased arachidonic acid-i nduced thromboxane B-2 formation by 87.1% in washed platelets. Ten mg . kg .(-1) of copper-aspirin complex given intragastrically markedly increased t he plasma level of 6-keto-prostaglandin F-1 alpha. Aspirin, however, reduce d both thromboxane B-2 formation and 6-keto-prostaglandin F-1 alpha level. In the presence of CaCl2 1 mmol L-1, copper-aspirin complex (20, 40 and 80 mu mol L-1) markedly lowered arachidonic acid-induced increase in platelet calcium from the resting level (270+/-36 nmol L-1) to 213+/-14, 170+/-20 an d 135+/-17 nmol L-1, respectively. In the presence of ethylene glycol-his ( beta-aminoethyl ether) N,N,N',N'-tetraacetic acid 1 mmol L-1, copper-aspiri n complex (20, 40 and 80 mu mol l.L-1) significantly suppressed the release of intracellular calcium induced by arachidonic acid from 127+/-23 nmol L- 1 to 108+/-17, 93+/-12 and 70+/-13 nmol L-1.