[Methodologic studies of the activation and inhibition of thrombin]

Conventional analysis methods of prothrombin and thrombin are not able to measure thrombin generation and inhibition quantitatively and specifically, neither analyses of the interactions of plasmatic coagulation with vessel wall components and platelet substances are possible until now. Therefore, photometric and micro-coagulation methods have been developed for quantitative and specific analyses of thrombin generation and inhibition. The following reagents were used: plasma prothrombin, thrombin, which is generated in plasma, human factor Xa, human fibrinogen, a chromogenic substrate, phospholipids and calcium. To confirm the validity of the methodology various examples of application are demonstrated: the analysis of carboxylated and non-carboxylated prothrombin in human hepatic cells, the analysis of the thrombin generation and inhibition induced by endothelial cells and smooth muscle cells and the proof of a reduced platelet factor 3 availability in patients with various platelet aggregation defects.