Platelet release reaction and prostaglandin pathway activation in angina patients during exercise: effect of indobufen.

Platelet 14C-serotonin release induced by collagen, and platelet malondialdehyde (M.D.A.) generation induced by thrombin were assessed in twenty patients with stable angina, before and after exercise with a bicycle ergometer. The patients received a single oral 200 mg dose of indobufen or placebo according to a crossover design in double-blind conditions. The M.D.A. concentration increased when exercise was carried out after placebo, whereas indobufen markedly inhibited M.D.A. production and 14C-serotonin release. These results suggest that effort may be an important factor in activation of the platelet prostaglandin pathway and that the use of antithrombotic drugs may be appropriate in patients with angina.