Changes In Acute Pulmonary Embolism Pulmonary Surfactant And Drug Intervention Effect Experimental Research

[Backgrounds]Acute pulmonary embolism(PE) is a commonly encountered disease which may occur following many diseases such as lower limbs diseases, tumor, post-operation, fracture, trauma, pregnant and heart disease, etc. The clinical presentations of PE can be from without evident symptom to sudden death. The most frequent symptom is breathlessness resulting from hypoxemia with incidence of about 80%-90%. The main causes of hypoxemia are lung ventilation/perfusion imbalance and right to left shunt, and the anatomy basis of pathological changes are pulmonary edema, alveolus trap and pulmonary atelectasis. Studies showed that acute lack of oxygen or blood can lead to functional injury of type II pneumonocytes with decreased pulmonary surfactant synthesis, which lead to alveolus trap and pulmonary atelectasis and then right to left flow, and hypoxemia.PS is composed of phospholipid and the specific combined proteins (surfactant associated proteins, SPs). Phospholipid can reduce the surface tension of alveolus, SPs are the necessary part in this process. About 50% of SPs is surfactant associated proteins A (SPA), it is the most important part and plays an important role in physiological condition and many lung diseases. SPA in BALF is a early parameter of functional injury of type II pneumocyte, and is parameter of degree and prognosis of lung injury. The phospholipid synthesis of embolic lung tissue decreased in acute PE, but the change of SPA is not known. To further study the changes of PS in PE and the effects of medicine may be of important significance for the improvement of hypoxemia of PE.[Objective]1, Establish the rat model of acute pulmonary embolism.2, Study the changes of SPA in lung tissue, BALF and blood in PE. 3, Study the changes of phospholipid in BALF.