Inflammatory cytokines are key components for discoid platelet attachment and thrombus development in our laser/ROS-induced injury model. (A) In vivo imaging of thrombus formation in small-sized mesenteric arterioles of 12-week-old male TNF-α KO, TNF-R1 KO, and IL-1-α/β double KO mice and wild-type (WT) controls. The red arrows show the developing thrombi, and white arrows show the direction of blood flow. Numbers of platelets attached to the vessel wall 10 seconds after laser/ROS-induced injury (B) and numbers of platelets within the developing thrombus 20 seconds after injury (C) in each mouse type. The initial attachment of platelets to ECs after laser/ROS-induced injury was significantly diminished in all inflammatory cytokine KO mice, as was thrombus development. (D-L) Numbers of platelets attached to the vessel wall 10 seconds after laser/ROS-induced injury (D,G,J) and numbers of platelets within the developing thrombus 0 seconds, 10 seconds, and 20 seconds after injury (E,H,K) in mesenteric capillaries of 12-week-old male TNF-α (D-E) and TNF-R1 (G-H) KO mice, IL-1-α/β double KO mice (J-K), and their respective WT littermates. (F,I,L) In vivo imaging of thrombus formation within capillaries of TNF-α KΟ, TNF-R1 KO, and IL-1-α/β double KO mice and WT mice. The white arrows show the direction of blood flow. Both “attachment” and “development” were diminished in all inflammatory cytokine KO mice. Horizontal lines denote median values (E,H,K). (n = 30 vessels from 5 animals for each group). All scale bars are 10 μm.