Thrombogenic effects of xenobiotics

The mechanisms by which xenobiotics may cause or promote thrombosis include vascular damage, induction of a hypercoagulable state and disturbances of blood flow. This paper discusses the methods available to detect various types of thrombogenic substances. Pathomorphological techniques are best suited to demonstrate thrombosis caused by localized vascular damage or generalized endothelial lesions. For the assessment of disseminated microcirculatory thrombosis, the consumption of platelets and clotting factors and the appearance of specific platelet proteins and fibrinogen and fibrin split products can be determined in the blood. Hypercoagulability which is defined as a perturbation of the hemostatic equilibrium resulting in a shift in the direction of thrombosis, is of particular importance in toxicology. Many in vitro, ex vivo and in vivo methods have been proposed to detect and to measure the ability of xenobiotics to induce a prethrombotic state. Their usefulness is demonstrated with several examples.