Abcc4 KO platelets have reduced aggregation with reduced thrombus formation in vivo. (A) Collagen-mediated, Abcc4 WT, and KO platelet aggregation measured using PRP in a Chronolog aggregometer with various concentrations of collagen. Platelet aggregation was performed 3 times with PRP pooled from 3 to 5 mice for each genotype. The bar represents 1 standard deviation. (B) PRP was used to determine the platelet binding to collagen-coated plates and the optical density (AU) (*P < .05). The binding assay was performed twice and the data were derived from pooled PRP of 3 to 5 individual mice per genotype per experiment. The bar represents 1 standard deviation. (C) Representative image of the spreading of Abcc4 KO and WT platelets on fibrinogen-coated coverslips. (D) The surface area covered by each platelet was determined for 200 platelets and 10 independent fields. This experiment was repeated twice with pooled PRP, with the data derived from 3 individual mice of each genotype shown. The bar represents 1 standard deviation for platelet surface area. (E) The mean time to vessel occlusion was calculated from FeCl3 experiments performed on 5 to 8 mice per group. (F) Percentage of thrombin-mediated platelet aggregation measured using Abcc4 WT and KO-derived PRP by a Chronolog aggregometer after incubation with various thrombin concentrations. (G) Percentage of ADP-mediated platelet aggregation measured using derived PRP. (H) A representative aggregation tracing of PRP from Abcc4 WT and KO mouse treated first with 0.625 μg/mL collagen and, at the indicated time, 1.25 μΜ ADP. Platelet aggregation experiments were performed 3 times using PRP derived from 3 to 5 individual mice per genotype. The bar in each graph represents 1 standard deviation (*P value < .05).
