重组水蛭素的抗血栓形成作用及其机制

目的：研究重组水蛭素抗血栓形成的作用及机制。方法：将60只雄性昆明小鼠随机分为对照组、模型组、阿司匹林组和重组水蛭素低、中、高剂量组（n=10）。除对照组外，其余各组小鼠分别腹腔注射角叉菜胶2.5 mg/kg，诱发小鼠尾部血栓形成。注射角叉菜胶前24 h、0.5 h和注射后24 h，阿司匹林组小鼠分别腹腔注射阿司匹林25 mg/kg，重组水蛭素低、中、高剂量组小鼠分别腹腔注射0.05、0.1、0.2 mg/kg重组水蛭素，对照组和模型组小鼠分别腹腔注射等体积生理盐水。注射角叉菜胶后48 h，观察小鼠黑尾长度并计算黑尾发生率；检测血浆凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、组织型纤溶酶原激活剂（t-PA）、纤溶酶原激活物抑制因子-1（PAI-1）、6-酮-前列腺素F1α（6-keto-PGF1α）、血栓恶烷B2（TXB2）水平。结果：与对照组比较，模型组小鼠尾部形成血栓；血浆PT明显缩短（P<0.01），PAI-1、TXB2水平明显升高（P<0.01），t-PA、6-keto-PGF1α水平明显降低（P<0.01）。与模型组比较，重组水蛭素低、中、高剂量组和阿司匹林组小鼠尾部血栓长度明显缩短（P<0.05或P<0.01），PT明显延长（P<0.01），PAI-1、TXB2水平明显降低（P<0.01），t-PA、6-keto-PGF1α水平明显升高（P<0.01）。与阿司匹林组比较，重组水蛭素低剂量组小鼠尾部血栓长度明显增加（P<0.05），PT明显缩短（P<0.01），PAI-1、TXB2水平明显升高（P<0.01）；重组水蛭素低、中剂量组6-keto-PGF1α水平明显降低（P<0.01，P<0.05）；重组水蛭素中剂量组PAI-1、TXB2水平明显升高（P<0.01，P<0.05）。结论：重组水蛭素有明显抗血栓形成作用，其机制可能与影响外源性凝血系统、促进纤溶功能有关。

Antithrombotic effects of recombinant hirudin in mice and its mechanism

Objective: To investigate the antithrombotic effects of recombinant hirudin and its mechanism. Methods: Sixty male Kunming mice were randomly divided into 6 group (n=10):control group, model group, aspirin (25 mg/kg) group, recombinant hirudinlow, middle and high dose (0.05, 0.1, 0.2 mg/kg) groups.Except mice in control group, 2.5 mg/kg carrageenan was injected intraperitoneallyto mice in the other groups to produce thrombosis on the mice tail. The mice in aspirin group were administrated intraperitoneally 25 mg/kg aspirin, the mice in recombinant hirudinlow, middle and high dose groups were administrated intraperitoneally 0.05, 0.1, 0.2 mg/kg combinanthirudin, the mice in control group and model group were administrated intraperitoneallynormal saline at the same volume respectively at 24 h, 0.5 h before injecting carrageenan and 24 h after injecting carrageenan. The black tail length of mice and the incidence of black tail were observed at 48h after injection of carrageenan; prothrombin time (PT), activated partial thromboplastin time (APTT), tissue plasminogen activator (t-PA), type-1 plasminogen activator inhibitor (PAI-1), 6-keto-PGF1α, and thromboxane B2 (TXB2) level in mice plasma were determined. Results: As compared with control group, the mice in model group presented tail thrombosis; PT level in plasma was significantly shortened (P<0.01), PAI-1 and TXB2levels in plasma were significantly increased (P<0.01), while the t-PA and 6-keto-PGF1α levels in plasma in model group were significantly decreased (P<0.01). As compared with model group, the thrombus length in the tail was significantly shortened (P<0.05, P<0.01), PT level was obviously prolonged (P<0.01), and the plasma levels of PAI-1 and TXB2 were significantly decreased (P<0.01), while the plasma levels of t-PA and 6-keto-PGF1α were significantly increased (P<0.01)in the mice of recombinant hirudin low dose, middle dose, high dose groups and aspirin group. As compared with aspirin group, the thrombus length in the tail was significantly increased (P<0.05), PT level was obviously shortened (P<0.01), and the plasma levels of PAI-1 and TXB2 were significantly increased (P<0.01)in the mice of recombinant hirudin low dose group; the plasma level of 6-keto-PGF1α was significantly decreased (P<0.01, P<0.05) in the mice of recombinant hirudin low dose and middle dose groups; the plasma levels of PAI-1 and TXB2 were significantly increased (P<0.01, P<0.05)in the mice of recombinant hirudin middle dose group. Conclusion: The recombinant hirudin can fight against thrombosis, its antithrombotic mechanisms may be related to its influence on the exogenous coagulation system and the promotion of fibrinolysis function.