[Level of tissue plasminogen activator protein in pulmonary artery in acute pulmonary thromboembolism in rabbit]

To study the changes in tissue plasminogen activator(t-PA) protein in pulmonary artery and its clinical significance after acute pulmonary thromboembolism (PTE).Thirty rabbits were randomly divided into four groups after replicating a model of acute PTE in rabbit by thrombi occlusion method. Specimens were obtained from both normal and morbid pulmonary artery 3, 8 and 24 hours after APE, and protein contents of t-PA were determined using immunohistochemical method.A few endothelial cells and smooth muscle cells of the normal pulmonary artery were positive for t-PA. After 3 hours of PTE, there was no significant changes in t-PA positive stain among embolismic, non-embolismic and normal pulmonary artery. After 8 and 24 hours of PTE, strong positive staining was found in the residual endothelial cells and a part of smooth muscle cells (all P0.01).There is significantly strong positive staining for t-PA in the pulmonary artery wall after pulmonary embolism, implying that the local fibrinolysis activity was enhanced, and it might be helpful for lysis of the embolus.