Mechanism And Significance Of Murine Pulmonary In Situ Thrombosis Induced By Microthrombotic Particles

Objective Develop a new model of pulmonary in situ thrombosis in mice, to imitate the pathophysiologic course of clinical pulmonary microembolism and set up a effective research platform for it; detect expression of fgl2 in the lung tissues to investigate the possible mechanism of in situ thrombosis in the model.Methods 80 mice were randomly divided into model group, sham group and control group. Each group was divided into five subsets according to time. The model of pulmonary microthrombosis was induced by 0.1 mL microthromb particles injected through internal jugular vein. 0.1 mL normal saline was injected instead of microthromb particles in sham group. Nothing special was done to control group. The pulmonary tissue was observed generally and then stained by HE and modified MSB, and the amount of platelets in peripheral blood and arterioles with microthrombosis were calculated respectively. The expression of fgl2 was then detected by PR-PCR and immunohistochemistry staining respectively.Results①Platelets in both model group and sham group were decreased , and platelets in model group is lower than sham group significantly (P<0.01).②Engorgement and hemorrhagic focus were seen on the surface of lung in model group, no obvious pathology change was observed in sham group and control group.③It showed in HE staining that in model group besides microthromboembolism induced by injected microthrombotic particles, newly-formed microthromb could be observed, and the amount of arterioles with microthrombosis in model group is higher than that in sham group significantly(P<0.01), but there was no significant difference between sham group and control group(P>0.05).④It showed in MSB staining that it is positive in model group and negative in shame group and control group.⑤Fgl2 was detected to express in model group by both RT-PCR and immunohistochemistry staining, and expression in 1d subset was higher than other subsets. No obvious expression was detected in Shame group and control group.Conclusion①Microthrombotic particles can induce pulmonary in situ thrombosis in mice successfully, and the new model is effective on the study of pulmonary thromboembolism.②Fgl2 prothrombinase may participate in the process of microthrombosis and play an important role in coagulation.