重组尿激酶型纤溶酶原激活物对实验性肺血栓栓塞症内源性纤溶的影响

Effect of recombinunt urokinase - type plasminogen activator on endogenous fibrinolysis of experimental pulmonary embolism

目的探讨重组尿激酶型纤溶酶原激活物（ru-PA,又称外源性u-PA）不同用药方案对实验性肺血栓栓塞症内源性纤溶的影响。方法通过颈外静脉注入^125碘（^125I）-标记人纤维蛋白原的大鼠加热血凝块,建立大鼠肺血栓栓塞症（PTE）模型。按随机原则将70只大鼠分成三大组：①假手术组;②PTE溶栓治疗对照组,含4个亚组：PTE 2 h组,PTE 1 d组,PTE 3 d组和PTE 5 d组;③PTE后3 d溶栓组,含2个亚组：多次用药组和单次用药组。用药后2 h处死大鼠,取血、肺及心脏,测量每分钟γ放射性。以10%甲醛固定肺组织,制成组织切片,行苏木精-伊红（HE）染色、Masson染色及原位杂交。结果PTE 2 h、1 d、3 d及5 d组血管栓塞部位内皮细胞u-PA、u-PAR、PAI-1 mRNA及t-PAmRNA的表达均阳性,假手术组均为阴性。定量分析示：①PTE 2 hu-PA及u-PAR mRNA表达最低,3 d最高（P均=0.000）,5 d与1 d比较,差异无统计学意义（P=0.745及0.642）。②PTE 2 h PAI-1的mRNA表达最低（P均=0.000）,PTE 1 d与3 d、5 d组比较,差异无统计学意义（P=0.579及0.757）。③各组间t-PA mRNA表达差异无统计学意义（F=2.0,P=0.127）。④经相关分析,PTE 2 h、1 d、3 d及5 d组u-PAR mRNA与u-PA mRNA表达呈正相关（r=0.700,P=0.024;r=0.658,P=0.039;r=0.666,P=0.035;r=0.774,P=0.009）。多次用药组血管栓塞部位u-PA mRNA表达及溶栓率明显高于单次用药组及对照组（P均〈0.001）,单次用药组明显高于对照组（P均=0.000）。多次用药组u-PAR mRNA表达明显高于对照组（P=0.001）,但与单次用药组比较,差异无统计学意义（P=0.063）。结论外源性u-PA的溶栓效果及对PTE内源性纤溶的影响与不同的用药方案有关。外源性u-PA可作用于u-PA系统,促进内源性u-PA及u-PAR的合成,加强纤溶作用。

Objective To observe the effects of recombinant urokinase - type plasminogen activator （ ru - PA） on endogenous fibrinolysis of experimental pulmonary embolism. Methods 1251 - labeled human fibrinogen heated blood clots were produced in vitro and were injected into the external jugular vein to establish rat models of pulmonary thromboembolism （PTE）. seventy male Sprague Dawley（SD） rats were assigned randomly into 3 groups：①sham group;②PTE without receiving thrombolytic treatment groups, including 4 subgroups ： PTE 2 h, PTE 1 d, PTE 3 d and PTE 5 d group ;③PTE 3 d receiving ru - PA thrombolytic treatment group, including 2 subgroups ： multiple medication group and single medication group. Results ①The expressions of u - PA,u - PAR, PAI- 1 and t - PA mRNA were undetectable in the sham group. The u - PA and u - PAR mRNA expression in sections of thrombosed vessels were lowest in PTE 2 h group（ P =0.000）, and were highest in PTE 3 d group （P =0.000） and were no significant difference between PTE 1 d and PTE 5 d group （P = 0. 745 and 0. 642）. ②Compared with the 2 h group, the PAl - 1 mRNA expressions of PTE 1 d group, 3 d group, 5 d group were up - regulated markedly （ all P = 0. 000 ）. There were no significant differences as compare PTE 1 d with PTE 3 d and 5 d group（ P =0.579 and 0.757）. ③ The t -PA mRNA expressions in all of these groups did not reveal a significant difference （ F = 2. 0,P =0. 127）. By correlation analysis, in the PTE 2 h, 1 d, 3 d and 5 d group, the expressions of u - PA and u - PAR mRNA appeared markedly positive correlation （ r = 0. 700, P = 0. 024 ;r = 0. 658, P = 0. 039 ;r = 0. 666, P = 0. 035 ;r = 0. 774, P = 0. 009 ）. Compared with the single medication group, the expressions of u - PA mRNA and the rats of clot lysis of multiple medication group increased significantly （ both P 〈 0,001 ）. Both of that increased significantly as compare the single medication group and the multiple medication group with the control group （ all P = 0. 000 ）. The expression of u - PAR mRNA of the multiple medication group was higher than that of the control group（ P = 0.001 ）, but was not higher significantly（ P = 0. 063 ）than that of the single medication group（ P = 0.063 ）. Conclusion The different medication schedule of ru - PA affects thrombolysis and endogenous fibrinolysis; ru - PA may promote the synthesis of endogenous u - PA and u - PAR by affecting u - PA system, enhance fibrinolysis.