肺血栓栓塞后组织型纤溶酶原激活物及其抑制物-1在肺动脉中的表达

Expression of tissue plasminogen activator and inhibitor-1 after acute pulmonary thromboembolism in rabbit

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)及其抑制物-1(PAI-1)在肺动脉中表达的动态变化,了解急性肺栓塞后机体纤溶能力的变化。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,对照组输入生理盐水。用免疫组织化学及Westernblot方法检测对照组及栓塞后即刻、4、8、24h栓塞部位肺动脉组织中t-PA及PAI-1蛋白表达水平。结果t-PA在栓塞后即刻和4h未见明显表达,8h和24h表达明显增强;半定量蛋白结果显示t-PA在栓塞后4h表达开始增高,8h进一步增强,24h达高峰。与各对照组比较,有显著性差异(P<0·05)。PAI-1在栓塞后即刻及24h均见明显表达,而在栓塞后4h和8h表达明显减少;半定量蛋白结果显示PAI-1在栓塞后4h开始降低,8h降至低峰,与各对照组比较,有显著性差异(P<0·05)。PAI-1在栓塞后24h表达有所恢复。结论兔急性肺栓塞后,t-PA表达水平随时间而逐渐增高,PAI-1表达呈现一过性降低,表明了在肺动脉栓塞早期,机体的纤溶功能明显增强,这与肺血管的t-PA和PAI-1表达平衡变化有关。

Objective To study the changes in tissue plasminogen activator（t PA） and inhibitor-1（PAI-1） expression in pulmonary artery after acute pulmonary thromboembolism（PTE）. Methods Rabbit acute pulmonary thromboembolism model was established by injection of auto-blood clots into femoral vein. Control group received injection of the same volume normal saline. The expression of t PA and PAI-1 was measured by immunohistochemical and Western blot at 0, 4,8 and 24 h after PTE. Results t-PA stainig was shown in the endothelial cells of the morbid pulmonary artery at 8 h after PTE but not in normal or morbid pulmonary artery at 4 h after PTE, which was supported by Western blot data. So did the results of PAI-1 staining. Conclusion The results indicate that the fibrinolysis activity is enhanced greatly after the early state of PTE in rabbit,and the balance between t-PA and PAI-1 is shifed, which might be helpful for lysis of the embolus.