Effects of the Arrb2^K296R mutation on platelet activation and thrombosis in the HHcy environment. (A) Schematic representation of the modeling strategies used to evaluate the antithrombotic effect of the Arrb2^K296R mutation on platelet aggregation. (B) Turbidimetric aggregometry revealed that ADP (5 μM), U46619 (350 nM), and thrombin (0.01 U/mL) induced platelet aggregation in washed platelets isolated from WT or Arrb2^K296R mice. The aggregation of WT platelets was significantly enhanced by preincubation with Hcy (100 μM), whereas the Arrb2^K296R mutation largely diminished the Hcy-induced increase in platelet aggregation. The data are from 4 independent experiments (n = 4). (C) Representative OCTA image of FeCl₃-induced mesenteric artery thrombosis at different time points in each group. The white arrows indicate the blood vessel where the clot occurred and red arrows indicate the ischemic area caused by thrombosis. (D) Vessel diameter indices for the different groups (n = 3 mice per group). Vessel diameter refers to the diameter length of the vessel, and the relative vessel diameter index refers to the degree of vascular blockage; the higher the index value, the narrower the blood vessel. (E) Occlusion time for male WT and Arrb2^K296R mice subjected to FeCl₃-induced carotid artery thrombosis and pretreated with phosphate-buffered saline, Hcy (100 mg/kg), or AHT (500 mg/kg) (n = 5 mice per group). The data are from 3 independent experiments (n = 3). ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. The bars represent means ± SEMs. All the data were analyzed using the 1-way ANOVA. β-arr2, β-arrestin2.