心肌组织TF表达对兔无复流作用的实验研究

目的：观察无复流区心肌组织因子（TF）mRNA表达，探讨心肌组织局部TF激活的外源凝血途径在兔实验性无复流（NR）中的作用。方法：将13只新西兰大白兔随机分为TF组（n=10）和对照组（n=3）：均予结扎回旋支（LCX）中段120min，再灌注60min，建立急性心肌梗死（AMI）后再灌注NR模型。在再灌注末，从左心房注入6％硫磺素S1ml／kg使复流区着色，NR区不着色；再于原位重新结扎LCX，TF组从左心房注入Evan’s蓝，使结扎区外着蓝色，缺血区不着蓝色，对照组不予Evan’s蓝。采用RT-PCR法检测TF组NR区、缺血区和正常区心肌组织TF mRNA表达；对照组光镜下观察不同心肌组织血栓形成和心肌损伤情况。结果：TF组NR区TF mRNA表达明显高于缺血区和正常区心肌组织（0．488±0．190对0．310±0．148对0．200±0．091，P〈0．05），但缺血区和正常区心肌组织TFmRNA表达无统计学差异（P〉0．05）。对照组NR区心肌组织可见较多血栓形成，心肌损伤程度明显加重。结论：NR区心肌组织局部TF表达增强，并在NR发病过程中起到重要促进作用。

Effect of myocardial expression of tissue factor on no-reflow phenomenon in rabbits

Objective：To observe the tissue factor （TF） mRNA expression in no-reflow （NR） myocardium, and also to study the effect of TF initiated extrinsic coagulation system on NR phenomenon in experimental rabbits. Methods：Thirteen New Zealand white rabbits were randomized into TF group （n = 10） and control group （n = 3）, which were subjected to 120 minutes of coronary artery occlusion and followed by 60 rain of reperfusion. At the end of reperfusion, size of NR area was delineated by intra-atrial injection of 1ml · kg^-1 of 6% thioflavin S, then the LCX was re-occluded, and Evans blue dye was injected into the left atrium to determine ligation size （ischemic area） in TF group. TF mRNA expressions in NR, ischemic area and normal myocardial areas in the TF group were measured by RT-PCR. Thrombi formation and myocardial injury in the control group were observed under light microscope. Results：In the TF group, TF mRNA expression in NR myocardial area was significantly higher than that in ischemic area and normal areas （0. 488 ± 0. 190 vs 0. 310 ± 0. 148 vs 0. 200 ± 0. 091, P〈0. 05）, no significant difference in mRNA expression between the isehemic area and normal area was found （P〉0. 05）. In the control group, thrombi formation andmajor injury were observed in the NR area. Conclusion：The local expression of TF mRNA in the NR area was significantly increased, and might play a pathogenic role in NR phenomenon in rabbits.