We studied the ability of a single oral dose of aspirin to inhibit prostacyclin synthesis by human arterial and venous tissue and to inhibit thromboxane A2 synthesis by platelets in 70 patients who were undergoing aortocoronary bypass. A dose of 40, 80, or 325 mg of aspirin was administered 12 to 16 hours before surgery. The generation of thromboxane in serum--which provides an estimate of platelet thromboxane production--was reduced from the control value by 77, 95, and 99 per cent after single doses of 40, 80, and 325 mg of aspirin, respectively. By contrast, prostacyclin production in aortic tissue that was removed at operation was reduced by only 35, 38, and 75 per cent, respectively, in response to these doses. Production of prostacyclin in saphenous-vein tissue (not tested after 40 mg of aspirin) fell only slightly and not significantly after 80 mg but was reduced by 85 per cent after 325 mg. These findings indicate that a low dose of aspirin (40 to 80 mg) can largely inhibit platelet aggregation and thromboxane synthesis but has much less effect on prostacyclin production in arterial and venous endothelium.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.