Abstract
Intimal injury was induced by inserting polyethylen tubing into the aorta of New Zealand white rabbit. The injury was restricted to the intima without interruption of the intimal elastic lamina. Platelet adhesion and aggregation were investigated by scanning or transmission electron microscopy. Microthrombus formation mainly composed of platelets was scatteredly observed at the injured areas.
More deep injury was induced by prickling a needle from the adventitia of the thoracic or abdominal aorta after thoracotomy or laparotomy, and scratching the opposite intima to the prickling site. The internal elastic lamina was interrupted and the deeper injury reaching the media of the aorta was induced. This injured area revealed prominent fibrin formation accompanied by adhesion of platelets on the fibrin network individually or in clusters.
Fibrin or fibrinogen coating on the surface of the platelet thrombi was demonstrated by immunohistochemical technique. These fibrin or fibrinogen was thought to play a significant role for the fixation and growth of the mural thrombi.
Therefore, we should take account of the treatment which promotes the fibrinolysis as well as the treatment which prevents the platelet aggregation when we treat the thrombosis.
