Human platelet-rich plasma clotted by reptilase does not retract. This seems to be due to the lack of activation of platelets exposed to this enzyme rather than to the incomplete hydrolysis of fibrinogen. Indeed, when aggregating agents such as ADP, collagen, adrenaline or Thrombofax are preincubated with unstirred PRP before adding reptilase, strong clot retraction occurs. A number of antiaggregating compounds has been evaluated in this test system. Only specific inhibitors of the release reaction were unable to influence ADP-reptilase or collagen-reptilase clot retraction. This procedure allows simple and sensitive evaluation of certain agents inhibiting the platelet adhesion-aggregation reaction. A scheme linking the platelet adhesion-aggregation reaction and clot retraction and indicating the level of inhibition of several compounds is proposed.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine