Summary
Pretreament of normal human platelets with colchicine at a final concentration of 10-3 M strikingly modifies their subsequent reaction to ADP. The generation of platelet factor 3 activity is inhibited, the secondary wave of aggregation fails to appear, and platelet factor 4 is not released. Colchicine also inhibits the increase in platelet factor 3 activity that results from washing and centrifugation of platelets.