The effect of 10 μg/kg IV bolus of A1-L on ex vivo platelet aggregation in PRP stimulated with 20 μmol/L ADP (A) and platelet count in whole blood (B) in ketamine-sedated chimpanzees. (▴) Inhibition of platelet aggregation as measured by a change in light transmittance (PPP 100%) under stirring conditions (1,100 rpm) at 37°C in Biodata Platelet Aggregation Profiler for chimpanzee A-264 and five control chimpanzees (mean ± SEM, n = 6). Platelet count measured in whole blood using a Coulter Cell Counter for (•) control chimpanzees (mean ± SEM, n = 5) and (▪) chimpanzee A-264.