Fibrinogen as a factor of thrombosis: experimental study.

Epidemiological, clinical, and experimental studies have clearly demonstrated the strong association between baseline fibrinogen level and risk of thromboembolic complications. The pathogenesis of postoperative or post-traumatic thrombosis in man is associated with fibrinogen level in plasma. The purpose of this study was to evaluate the effects of fibrinogen administration on thrombus formation at different dosages. To investigate these effects, we used an experimental model of induced thrombosis in rat microcirculation. This model allows single endothelial cell destruction by laser injuries, thus leading to thrombus formation. Fibrinogen was injected intravenously via penis vein and tested at various dosages (50, 100, and 200 mg/kg), 60 minutes after injection on arterial thrombosis induction and 120 minutes after injection on venous thrombosis induction. Results showed that the administration of fibrinogen increases the number of emboli, the duration of embolization, the amplitude, and the velocity of the ex-vivo platelet aggregation induced by ADP (p < 0.05). A positive correlation between the percent of fibrinogen increase in plasma and the enhancement of thromboembolic risk in the experimented animals was observed.