组织因子和组织因子途径抑制物1对无复流作用的实验研究

目的 观察缺血再灌注时兔心肌组织和血浆中组织因子(TF)和组织因子途径抑制物1(TFPI-1)水平的变化,研究外源性TFPI-1对无复流严重程度的影响,探讨TF激活的外源性凝血系统及TFPI-1抑制途径在无复流发病过程中的作用.方法 40只新西兰大白兔随机分为4组(每组10只):缺血再灌注组(IR组,结扎回旋支120 min,再灌注60 min)、缺血再灌注TFPI-1组(TFPI-1组,再灌注时rTFPI-1 100 ng/kg静脉注射,1ng·kg~(-1)·min~(-1)静脉滴注)、缺血组(结扎回旋支180 min)和假手术组,每组10只.用硫磺素S和Evan's蓝活体染色区分无复流区和缺血区.无复流严重程度用无复流面积/缺血面积表示.用逆转录-聚合酶链反应方法测定无复流区、缺血区及正常区心肌组织TF和TFPI-1 mRNA表达水平,ELISA方法测定开胸前、冠状动脉结扎前即刻及结扎120 min、再灌注10和60 min血浆TF和TFPI-1水平.结果 开胸前、冠状动脉结扎前即刻及结扎120 min,各组血浆TF、TFPI-1水平差异无统计学意义(P>0.05);再灌注10和60 min时,IR组血浆TF水平均显著高于缺血组和假手术组[10min:(20.7±4.1)pg/ml比(13.9±2.2)pg/ml(P<0.001),(20.7±4.1)pg/ml比(13.2±2.6)pg/ml(P<0.001);60 min:(15.8±2.6)pg/ml比(13.5±1.6)pg/ml(P<0.05),(15.8±2.6)pg/ml比(12.1±0.7)Pg/ml(P<0.001)].再灌注10 min时,IR组血浆TFPI-1水平较缺血组及假手术组无明显变化(P>0.05);60 min时,血浆TFPI-1水平[(9.7±1.6)ng/ml]反而显著低于缺血组[(11.6±1.6)ng/ml,P<0.05]及假手术组[(10.1±1.3)ng/ml,P<0.01].IR组无复流区心肌组织TF mRNA表达高于缺血组及假手术组(P<0.05或P<0.001);TFPI-1 mRNA表达较缺血组无明显变化(P>0.05).TFPI-1组无复流严重程度明显低于IR组(0.39±0.11比0.54±0.06,P<0.01).结论 无复流区心肌组织TF转录水平及再灌注过程中TF血浆蛋白水平表达明显上调;而无复流区心肌组织TFPI-1转录水平无明显变化,再灌注过程中血浆蛋白水平反而相对降低;外源性rTFPI-1可以减轻无复流严重程度.TF激活的外源凝血途径在无复流发病过程中起到重要作用.

Effects of tissue factor pathway inhibitor-1 on no-reflow in a rabbit model

Objective To investigate the role of plasma tissue factor (TF) and tissue factor pathway inhibitor-1 (TFPI-1) level and to observe the effect of extrinsic TFPI-1 on no-reflow (NR) in a rabbit model of ischemia/reperfusion. Methods Rabbits were randomized into four groups (n = 10 each): ischemic- reperfusion group (IR, subjected to 120 minutes of coronary artery occlusion and followed by 60 minutes of reperfusion); ischemic- reperfusion TFPI-1 group (100 ng/kg bolus and 1 ng · kg~(-1) · min~(-1) infusion during reperfusion) ; ischemic group (subjected to 180 minutes of coronary artery occlusion) and sham group. The NR area and ischemic area were determined by thioflavin S and Evan's blue staining in vivo. Plasma TF and TFPI-1 levels were measured before operation, before and at 120 minutes post coronary artery ligation, 10 and 60 minutes after reperfusion by ELISA. Results Plasma TF and TFPI-1 levels before and at 120 minutes post coronary artery ligation were similar among the four groups (all P > 0.05). At 10 and 60 minutes after reperfusion, the plasma TF levels in the IR group was significantly higher than those in ischemic group and sham group [10 minutes: (20.7 ±4. 1) pg/ml vs. (13.9 ±2. 2)pg/ml(P <0. 001), (20.7±4. l)pg/ml vs. (13.2±2.6) pg/ml(P<0. 001); 60 minutes; (15.8±2.6) pg/ml vs. (13.5± 1.6) pg/ml(P<0.05), (15.8 ±2.6) pg/ml vs. (12.1 ±0.7) pg/ml (P < 0. 001)] while the plasma TFPI-1 levels were similar among IR, ischemic and sham groups at 10 minutes after reperfusion and at 60 minutes after reperfusion (all P >0. 05). TFPI-1 level [(9.7 ± 1. 6) ng/ml] was significantly lower in the IR group than in the ischemic group [(11.6 ±1.6) ng/ml, P < 0. 05] and sham group [( 10. 1 ±1.3) ng/ml, P < 0. 01] . TF mRNA expression in the NR area in IR group was significantly up-regulated compared to the ischemic group (P<0. 05) and sham group (P <0. 001 ) while TFPI-1 mRNA expression was similar between IR group and ischemic group ( P > 0. 05 ) . NR severity in the ischemic-reperfusion TFPI-1 group was significantly attenuated compared to IR group (0. 39 ±0. 11 vs. 0.54±0.06, P<0.01). Conclusion Upregulated TF mRNA expression in the NR area and increased plasma TF level during reperfusion period, reduced plasma TFPI-1 level during reperfusion period as well as attenuated NR severity by extrinsic application of human rTFPI-1 in this model suggested an important role in the pathogenesis of the NR phenomenon.