组织因子在大鼠脑微血管血栓形成中的表达

Expression of tissue factor in cerebral microvascular thrombosis in rats

目的探讨大鼠脑皮质微血管血栓模型中组织因子(TF)表达的动态变化及意义。方法50只SD雌性大鼠,随机分成正常对照组、血栓2h、4h、6h、24h组,每组10只,应用光化学法诱导脑皮质微血管梗塞模型。分别采用酶联免疫吸附法(ELISA)和免疫组化的方法检测脑血栓2h、4h、6h、24h血浆和脑血栓形成局部TF表达水平的变化。结果HE光镜和电镜观察的病理形态变化显示复制大鼠脑皮质微血管梗塞模型成功。血浆中TF含量4h、6h组显著高于正常对照组(P<0.01)。脑血栓局部微血管内皮细胞TF表达阳性,对照组为阴性,血栓6h和24h组TF平均吸光度值显著高于2h和4h组(P<0.01)。血浆中血管性血友病因子(vWF)含量2h(P<0.01)、4h(P<0.05)组显著高于正常对照组,抗凝血酶(AT)活性24h组显著高于其它各组(P<0.05)。结论光化学诱导大鼠脑血栓形成模型操作简单,稳定可靠,与人体血栓形成过程相似血管内皮损伤及内皮下TF暴露启动外源性凝血途径。组织因子凝血途径易化因素增强,表明TF参与大鼠脑皮质微血管血栓形成。

AIM： To study the expression of tissue factor （TF） in cerebral micmvaseular thrombosis and its dynamic changes in rats. METHODS： 50 female SD rats were randomized to control group, 2, 4, 6, and 24 hours after thrombosis groups, 10 rats in each group. The model of cerebral microvaseular thrombosis was induced by photo - chemical method. ELISA and immunohistochemistry methods were used to observe the changes of TF contents in blood plasma and the expression of TF in cerebral microvaseular in each group. RESULTS： Cerebral thrombosis was induced by photo-chemical method successfully. The TF content in plasma was obviously higher in 4 h and 6 h groups than that in control group （ P 〈 0.01 ）. TF intensely expressed on vascular endothelial cells in thrombosis groups and negatively expressed in control group. The average A value of TF in 6 h group and 24 h group was significantly higher than that in 2 h and 4 h groups （ P 〈 0.01 ）. It was also found that vWF content in plasma was obviously higher in 2 h group （ P 〈 0.01 ） and 4 h group （ P 〈 0.05） group than that in control group. AT activity in plasma showed obviously increased in 24 h group, compared with that in the others （ P 〈 0.05）. CONCLUSION： These findings suggest the photochemical infarct model is convenient to investigate cerebral thrombosis. TF plays an important role in thrombosis in this model.