Abstract:Objective: To develop a virulent heat-evil-induced thrombosis animal model, and provide a rational animal model for pathogeny and pathogenesis research of thrombosis-related diseases, anti-thrombosis activity screening and pre-clinical studies of CAHT formula. Method: SD rats were pretreated with carrageenin (Ca) intraperitoneal injection, followed by intravenous injection of endotoxin ( LPS from E. coli O111: B4) 50 μg·kg-1 16 h later. Thrombosis in rat tails were observed during 12-24 h after injection of LPS. The inflammatory mechanism of this model were investigated by analyzing serum level of TNF-α, IL-6, TXB2 and 6-keto-PGF1α, CD11b/CD18 expression of white blood cells (WBC) and P-selectin expression of vessel walls. Result: In LPS/Ca model group, thrombosis can be clearly observed in the distal part of rat tails after 12-24 h of LPS/Ca treatment. High level of TNF-α and IL-6 can be measured in serum. The expression of CD11b/CD18 in WBC and P-selectin in vessel endothelium significantly increased and the number of WBC in peripheral blood markedly decreased shortly after LPS/Ca treatment. The adherence of white blood cells to vessel endothelium which can be seen by microscope mainly contributed to the decrease of WBC. The results indicated that there was obvious inflammation after treatment with LPS/Ca, suggesting that inflammation was the key mechanism for this model. Conclusion: This model was developed through treatment of LPS in combination with Ca, of which LPS is considered to be an exotic virulent heat-evil in TCM, while the inflammatory molecules produced in this model, such as TNF-α, IL-6, CD11b/CD18 and P-selectin belong to internal virulent heat-evils, so this animal model consists of pathogeny and pathogenesis of virulent heat-evils. virulent heat-evil.