低分子量肝素对体内、体外血栓的溶解作用

目的：探讨低分子量肝素（ＬＭＷＨ）对体内、外血栓的溶解作用。方法：（１）取雄性家兔动脉血，制备人工血栓，放入贫血小板血浆中，观察ＬＭＷＨ对血栓的溶解作用；（２）于家兔一侧颈外静脉制备血栓，观察耳缘静脉用药（８００，４００，２００ＩＵ·ｋｇ－１）后静脉血栓溶解情况；同时测定ＡＰＴＴ、ＥＬＴ和血浆纤维蛋白原的含量。结果：不同于尿激酶，ＬＭＷＨ体外无溶栓作用；体内给药２００～８００ＩＵ·ｋｇ－１能有效地溶解体内血栓，降低纤维蛋白原的含量，缩短优球蛋白溶解时间（ＥＬＴ），并呈剂量依赖性，４００ＩＵ·ｋｇ－１溶栓作用与尿激酶５０００Ｕ·ｋｇ－１相似。结论：ＬＭＷＨ通过激活体内纤溶系统发挥溶栓作用。

The thrombolytic effect of low molecular weight heparin in vitro and in vivo

AIM: To study the thrombolytic effects of Low Molecular Weight Heparin (LMWH) in vitro and in vivo. METHODS: (1) The thrombi, which were produced from the blood of the male rabbits, and LMWH were put together in PPP, to observe the thrombolytic effect of LMWH in vitro ; (2) After the rabbit jugular vein clots were formed, the rabbits were given LMWH in vein, to observe the thrombolytic effect of LMWH in vivo . APTT, ELT and fibrinogen were determined. RESULTS: LMWH did not show thrombolytic effect on artificial thrombi in thrombolytic model in vitro, but it was effect on rabbit jugular vein clot. LMWH (400 IU·kg -1 , iv) showed the significant clot lysis similar to that of urokinase (5000 U·kg -1 ). LMWH brought about appreciable decrease in fibrinogen and ELT. CONCLUSION: LMWH exhibits thrombolytic activity by activating the fibrinolytic system in vivo.