Prostacyclin and thromboxane generating systems in rabbits pretreated with aspirin

Aspirin given orally to rabbits at doses of 5, 10 and 15 mg/kg partially suppressed arachidonate-induced ex vivo platelet aggregation and did not influence production of prostacyclin by the incubated mesenteric artery slices. Aspirin at doses of 25 and 50 mg/kg, p.o. completely inhibited platelet response to arachidonate, and heavily suppressed (by > 80%) arterial biosynthesis of prostacyclin. It is suggested that low doses of aspirin should be used in anti-thrombotic therapy.