Dynamic demonstration of thrombus embolization in fbg–/– mice compared to control, 7E9-treated, and γΔ5 mice. Characteristics of thrombus growth after FeCl3 injury. Single frames from the videos recorded through one eyepiece of the surgical microscope are shown, with blood flow proceeding from top to bottom. Thrombus formation at the site of the injury began rapidly in the mouse treated with control hamster IgG and the thrombus grew steadily more compact and dense without any significant macroscopic embolization. In the fbg–/– mouse, early platelet deposition was similar to that in the control mice, but the deposited platelets formed small loose thrombi that steadily embolized downstream from the site of the injury. Even though the thrombi at the site of the injury grew large, they were very unstable and repeatedly embolized. In the animal shown, a large, nearly occlusive thrombus formed after 20 minutes, but it soon began to stretch at one site (arrowhead) and then abruptly peeled off near its attachment to the vessel wall and embolized downstream. This particular embolus occluded the distal circulation, leading to transient cessation of blood flow. New thrombus deposition and additional embolization was visible at the site of injury 8 minutes later. Both 7E9-treated mice and γΔ5 mice differed dramatically from the control and fbg–/– mice in developing only small mural thrombi at the site of injury and only minimal embolization was observed. Original magnification × 15.
