Effect of acetylsalicylic acid on experimentally induced arterial thrombosis in rats

Abstract

Acetylsalicylic acid (ASA) was tested for its antithrombotic activity in the arterial system after prophylactic administration to rats, using a new standardized method. Damage of the vessel wall was produced by chilling a small segment of the left carotid artery. Dose related, significant results were obtained after 3 mg/kg orally. If higher doses (10 and 30 mg/kg) are administered, the formation of non-occlusive thrombi is inhibited by 70--90% on the basis of thrombus weight. As the frequency distributions show, there are significantly more zero-values in the ASA treated groups (total 50%) than in the control groups. However, the incidence of occlusive thrombi was not changed by ASA. The long-lasting effect of ASA in inhibition of platelet aggregation was confirmed. The formation of arterial thrombi is significantly inhibited after prophylactic administration of 30 and 10 mg/kg up to 48 h before initiation of thrombosis. After administration of 3 mg/kg orally, only insignificant effects were observed. Thus the duration of action depends on the dose used.