The Effect of Acetylsalicylic Acid on Platelet Adhesion in the Injured Abdominal Aorta

Abstract

The effect of a single oral dose of acetylsalicylic acid (ASA) on platelet adhesion in the rabbit abdominal aorta following a standard mechanical removal of the endothelium has been observed with both the scanning and transmission electron microscopes, in conjunction with studies on the agglutination properties of the platelets in vitro. It was found that the ASA did not prevent adhesion of platelets to the subendothelial surface although they did not appear to be adhering to the exposed collagen fibres but rather to endothelial basement membrane and microfibrils of the internal elastic lamina, often in small clumps. A large number of leucocytes were also observed adhering to the surface denuded to endothelium. The platelets obtained from ASA treated animals were morphologically normal, but unlike platelets obtained before treatment, did not adhere to collagen fibres in vitro; even when ADP was added the platelets adhered to one another but not to the collagen.

Quantification of the morphological reaction of platelets to aggregating agents and of its reversal by aggregation inhibitors.

“…For controls, 0-8 ml. ice-cold 2-5 % glutaraldehyde in 0-067 or 0-1 m-cacodylate buffer at pH 7-4 was added to fix the platelets (Sheppard, 1972). After stirring for 0-5 min the contents of the tube were poured into another tube containing 9 vol.…”