Quantitation of prothrombin activation products.

(A) A representative immunoblot displaying α-thrombin B chain (bottom band), prethrombin 2 (middle band), and F1.2 (upper band). Consecutive 30-second bleeding-time blood samples were separated on a 5% to 15% linear gradient SDS-PAGE gel under reducing conditions. Three activation products were probed with a polyclonal antibody, which recognizes prothrombin, prethrombin 1, prethrombin 2, fragment 2, prothrombin, and α-thrombin B chain. (B) Quantitative analysis of the generation of α-thrombin B chain (circles) in bleeding-time blood. This product, estimated by densitometry and comparison to standards, is presented as a function of time (seconds). Concentration of α-thrombin B chain before (open circles) and after aspirin (ASA) treatment (closed circles). Total amounts of thrombin B chain in each sample before (open triangles) and after aspirin treatment (closed triangles). Values are plotted as means ± SEM.