Effect of A11 and SLK on mouse platelet function in vivo and in vitro. (A) Effect of various doses of A11 or SLK (B) on platelet count decrease at the 4-hour nadir time point after injection in BALB/C mice. (C) Effect of Ab on induction of platelet count drop at different time points. Purified control scFv 13CG2, A11, and SLK were injected intravenously into BALB/C mice, and platelet counts followed for 24 hours; n = 4 (SEM). (D) Effect of Ab on mouse bleeding time. BALB/C mice were intravenously injected with control scFv 13CG2, A11, or SLK, and their bleeding time was monitored 4 hours later; n = 10 (SEM). (E) Effect of A11 and SLK on ADP-induced mouse platelet aggregation (%). Platelet aggregation was induced as the method described. Data are mean ± SD of at least 3 different determinations. (F) Effect of A11 and SLK on mouse platelet adhesion to immobilized ligands. Platelet adhesion was performed as described in “Assay of platelet aggregation and adhesion.” The extent of adhesion was expressed as the percentage of control platelets adhered without preincubation with A11 or SLK. Data are mean ± SD of at least 3 different determinations.