白细胞介素6水平在大鼠深静脉血栓形成中的变化

目的：探讨白细胞介素6（IL-6）在深静脉血栓形成（DVT）中的变化与作用。 方法：60只雄性SD大鼠随机分为假手术组（n=10）与模型组（n=50），模型组大鼠采用双侧股静脉钳夹联合后肢石膏制动诱导后肢DVT，并分别在造模后2、5、10、15、25 h各处死10只大鼠取材，观察股静脉血栓形成情况；用real-time PCR检测股静脉内皮组织IL-6 mRNA含量；ELISA法检测血清IL-6、纤溶酶原激活物抑制物（PAI）和纤溶酶原激活物（tPA）水平。 结果：模型组大鼠造模后2 h未见血栓形成，但从5 h开始出现血栓形成，并随着时间的延长，血栓形成逐渐增多。模型组大鼠股静脉内皮组织中的IL-6 mRNA水平在造模后逐渐升高，于15 h达高峰；模型组大鼠血清IL-6、PAI含量变化情况与IL-6 mRNA变化一致，但血清tPA浓度变化则与前两者相反。模型组以上各指标在各时间点与假手术组间的差异均有统计学意义（均P<0.05）。 结论：在大鼠DVT过程中IL-6水平升高，其可能通过促进PAI的产生、抑制tPA的活化来促进血栓的形成。

Alteration of interleukin 6 level in development of deep vein thrombosis in rats

Objective: To investigate the alteration of the interleukin 6 (IL-6) level in the development of deep vein thrombosis (DVT) in rats and its actions. Methods: Sixty male SD rats were randomly divided into sham operation group (n=10) and model group (n=50). Rats in model group underwent bilateral femoral vein clamping plus plaster cast immobilization of the hind legs to induce hind limb DVT, and were sacrificed at 2, 5, 10, 15 and 25 h after operation respectively, with 10 rats in each time point, to obtain the vein samples. Then, the incidence of thrombus formation in the femoral vein specimens was observed, IL-6 mRNA level in the endothelial tissue of the femoral vein was measured by real-time PCR, and the serum levels of IL-6, plasminogen activator inhibitor (PAI) and tissue plasminogen activator (tPA) were determined by ELISA assay. Results: No thrombus formation was observed in rats in model group 2 h after operation, but thrombosis began to occur 5 h after operation and was increased with time. In rats of model group, the IL-6 mRNA level in the endothelial tissue of the femoral vein was gradually increased after operation, and reached the peak at postoperative 15 h; the alterations of both the serum IL-6 and PAI levels showed the same pattern of the alteration of the IL-6 mRNA level, while the serum tPA level presented the completely opposite changing pattern of the serum IL-6 and PAI levels. All the differences in above parameters at each observed time point in model group reached statistical significance in comparison with those in sham operation group (all P<0.05). Conclusion: IL-6 level is increased during the process of development of DVT in rats, and this may promote thrombosis through increasing PAI production and inhibiting tPA activation.