Characterization of Ferric Chloride-Induced Arterial Thrombosis Model of Mice and the Role of Red Blood Cells in Thrombosis Acceleration

PURPOSE: The ferric chloride (FeCl(3))-induced thrombosis model is widely used for thrombosis research. However, it lacks standardization with uncertainty in the exact mechanism of thrombosis. This study aimed to characterize thrombus formation in a mouse model. MATERIALS AND METHODS: We investigated thrombus formation and stability using various FeCl(3) concentrations (10%, 20%, 30%, 40%, and 50%, w/v) in carotid arteries of the Institute of Cancer Research (ICR) and C57BL/6N mice using the FeCl(3)-induced thrombosis model. We also investigated thrombus histopathology using immunohistochemistry and electron microscopy. RESULTS: Higher FeCl(3) concentrations induced dose-dependent, faster, larger, and more stable thrombus formation in both strains of mice. However, the ICR mice showed better dose-responses in thrombus formation and stability compared to the C57BL/6N mice. Thrombi were fibrin- and platelet-rich without significant changes across FeCl(3) concentrations. However, the content of red blood cells (RBCs) increased with increasing FeCl(3) concentrations (p for trend <0.001) and inversely correlated with time to occlusion (r=-0.65, p<0.001). While platelets and fibrin were evenly distributed over the thrombus, RBCs were predominantly located near the FeCl(3) treatment area. Transmission electron microscopy showed that RBCs attached to and were surrounded by aggregates of degranulated platelets, suggesting their potential role in platelet activation. CONCLUSION: Faster and larger thrombus formation is induced in a dose-dependent manner by a wide range of FeCl(3) concentrations, but the stable thrombus formation requires higher FeCl(3) concentrations. Mouse strain affects thrombus formation and stability. RBCs and their interaction with platelets play a key role in the acceleration of FeCl(3)-induced thrombosis.