组织型纤溶酶原激活物在兔实验性肺血栓栓塞肺动脉中表达的动态变化及临床意义

目的通过研究兔实验性肺血栓栓塞(PTE)后组织型纤溶酶原激活物(t-PA)在肺动脉中表达的动态变化,了解急性肺栓塞后机体局部纤溶能力的变化。方法将48只日本健康大耳白兔随机分为栓塞组和对照组,栓塞组利用自体血栓经股静脉输入建立PTE模型,对照输入生理盐水。用免疫组织化学及Western blot方法检测对照组及栓塞后即刻,4、8和24 h栓塞部位肺动脉组织中t-PA蛋白表达水平。结果t-PA在栓塞后8 h和24 h表达明显增强,而在栓塞后即刻和4 h未见明显表达;半定量蛋白表达结果显示t-PA在栓塞后4h表达开始增高,栓塞后8 h表达进一步增强,24 h达到高峰,与各对照组比较,统计学有意义(P<0.05),与栓塞后即刻相比有显著性(P<0.05)。结论兔急性肺栓塞后,t-PA表达水平随时间而逐渐增高,表明了在肺动脉栓塞早期,机体的纤溶功能明显增强,这种内源性的纤溶能力的增强有利于血栓的溶解。

Level of Tissue Plasminogen Activator Expression After Acute Pulmonary Thromboembolism in Rabbit

Objective To study the changes in tissue plasminogen activator (t-PA) expression in pulmonary artery after acute pulmonary thromboembolism. Methods Rabbit acute pulmonary thromboembolism models by injecting auto-blood clots into femoral vein were used to observe the protein expression of tissue plasminogen activator (t-PA) in pulmonary artery, NC group receiving the same volume of saline. Specimens were obtained from both normal and morbid pulmonary artery 0,4,8 and 24 hours after PTE, and the expressions of tissue plasminogen activator (t-PA) were measured by immunohistochemical and Western blot. Result Immunohistochemical blot revealed t-PA staining in the endothelial cells of the morbid pulmonary artery 8 h after PTE but notin normal or morbid pulmonary artery 4 h after PTE. Staining data were supportedby Western blot data showing that t-PA protein expression in pulmonary artery increased rapidly 4 h after PTE but little in pulmonary artery of NC group(P<0.05). In contrast, the level of t-PA protein expressions in pulmonary artery in NC groupwere not elevated(P<0. 05). Conclusion There is significant strong positivestaining of t-PA in the pulmonary artery wall after pulmonary embolism, implyingthat the local fibrinolysis activity was enhanced after the early state of pulmonary-thromnoembolism in rabbit,and it might be helpful for lysis of the embolus.