Formation of platelet/neutrophil complexes after ischemia. Wild-type (Fpr2/3^+/+) and null (Fpr2/3^−/−) mice were subjected to clamping of the superior mesenteric artery, with blood being rapidly withdrawn at the end of the 30-minute ischemic period. Sham animals were anesthetized but not subjected to ischemia. (A) Flow cytometry scattergrams illustrating neutrophils (APC-Ly6G+)- and platelet (PE-CD41+)-positive events. The 4 quadrants show CD41+ events in the Ly6G+-gated population. Numbers in upper right quadrants indicate the percent of double-positive events (ie, the proportion of neutrophil/platelet complexes). (B) Cumulative data for platelet/neutrophil complexes. Mean ± SEM of 6 mice; **P < .01 vs respective sham group. (C-D) Chimeric experiment performed injecting CFSE-labeled platelets in recipient animals with the opposite genotype. Labeled platelets were injected immediately before ischemia, and blood was collected at the end of the 30-minute period; flow cytometry for APC-Ly6G+ and CFSE+ was then run, essentially as in (A). (C) Representative dot plots with the distribution of the 2 fluorochromes on all acquired events; (D) cumulative quantitative data. Mean ± SEM of 4 mice per group. *P < .05 and **P < .01 vs respective sham-operated mice.