Effect of acetylsalicylic acid on platelet aggregation and thromboxane B2 production in flowing aortic blood in the rat studied with a filter loop technique.

A method of measuring in vivo platelet function using a filter loop technique has been used to study platelet aggregation in response to Adenosine Diphosphate (ADP) and Sodium Arachidonate infusion in flowing aortic blood in the rat. ADP infusion produced reversible platelet aggregation in vivo with no change in thromboxane B2 (TXB2) levels whereas sodium arachidonate infusion resulted in virtually irreversible aggregation with a rise in TXB2 levels. Oral Acetylsalicylic Acid (ASA) in doses of 1-100 mg/kg had no effect on ADP induced aggregation but prevented platelet aggregation in vivo induced by sodium arachidonate and the concomitant rise in TXB2 levels.