Experimental Research Of Animal Model Establishment Of Chronic Pulmonary Thromboembolism And Pathophysiology Changes

Objective To establish a simple model with high success rate and close physiology to human of chronic pulmonary thromboembolism in animal.Methods Repeated injection of heat-treated (60～70℃water bath, 10～15 min),autologous blood clot (1ml/kg, adding coagulation 10U/ml facilitate their self-curing) was used to establish.CT angiography, lung anatomy and pathology were used to verify the feasibility of the model.Results Success rate of the animal model is 80% and chronic pulmonary thromboembolism have the fibrosis of thrombosis after the 4th week.Pulmonary CT angiography shows partial pulmonary truncated levy, as well as inflammation, infarction, pleural thickening and other indirect signs. Pulmonary anatomy and pathology studies can find pulmonary artery thrombosis and chronic inflammation such as machine-oriented in all rabbits of experimental group. Conclusion The method of repeated injection of autologous blood clot to establish model of chronic pulmonary thromboembolism have a higher viability.Objective To study the changes of D-dimer (D-Dimer, DD), blood oxygen partial pressure (Partial Pressure of Oxygen, PaO2) and blood carbon dioxide partial pressure (Partial Pressure of Carbon Dioxide, PaCO2) in chronic pulmonary thromboembolism animal model. To evaluate the status and role of DD , PaO2 and PaCO2 in diagnosis of chronic pulmonary embolism.Methods Repeated injection of heat-treated (60～70℃water bath, 10～15 min),autologous blood clot (1ml/kg, adding coagulation 10U/ml facilitate their self-curing) was used to observe DD, PaO2 and PaCO2 changes in rabbits.Results Compared with sham embolization, plasma D-D increased about 80% in 30 min after embolization(the difference was statistically significant, p <0.01). DD recovered to normal levels in the 4th week and continued to the 12th week (difference was not statistically significant, p> 0.05).PaO2 decreased and PaCO2 increased in 30 minutes after embolization (difference was statistically significant, p <0.01).The results recovered closely to normal levels from the 4th week to 12th week (no statistically significant difference, p> 0.05).Conclusions DD, PaO2 and PaCO2 can be used as screening tools of first step in patients of acute pulmonary embolism and chronic pulmonary embolism of early stage.Objective ET-1 level and BAX, BCL-2 protein expressions were monitored dynamically to explore the effects to pulmonary hypertension in the animal model of chronic pulmonary thromboembolism.Methods Repeated injection of heat-treated (60～70℃water bath, 10～ 15 min),autologous blood clot (1ml/kg, adding coagulation 10U/ml facilitate their self-curing) was used to observe ET-1,BAX and BCL-2 levels dynamically.Results With time extension of pulmonary embolism, ET-1 increased firstly and then decreased gradully.ET-1 levels in embolization group were higher than sham embolization group and differences were statistically significant (P <0.01).The differences between each group were also significant(P <0.01) after embolization.BAX and BAX / BCL-2 increased and then decreased firstly.They increased slowly at last.The differences were statistically significant (both P <0.01).BCL-2 didn't change obviously and the difference was not statistically significant (P> 0.05).Conclusion ET-1,BAX and BCL-2 have important roles to the formation of pulmonary hypertension in chronic pulmonary thromboembolism.Endothelin is concerned with the formation of pulmonary hypertension in chronic pulmonary thromboembolism. BAX, BAX / BCL-2 can promote apoptosis and are important factors to dysfunction of pulmonary vascular endothelium and pulmonary vascular remodeling.