Thrombin is the central protease in the coagulation cascade and one of the most extensively studied of all enzymes. In addition to its recognized role in the coagulation cascade and haemostasis, thrombin is known to have multiple pleiotropic effects, which mostly have been shown only in in vitro studies: it plays a role in inflammation and cellular proliferation and displays a mitogen activity on smooth muscle cells and endothelial cells, predominantly by activation of angiogenesis. Although several decades of research on thrombin have provided a framework for understanding its biology, studies are still needed to further characterise the functions of thrombin in disease. This monography deals with establishing of new models to study thrombin effects. The described experiments demonstrate that protracted intravenous infusion of thrombin offers an experimental model of consumption coagulopathy, where thrombin did not show pro-coagulant properties but led to a bleeding phenotype.