两种给药途径对低分子量肝素和肝素抗栓与抗凝作用的动物实验研究

 目的：观察比较低分子量肝素(LMWH)、肝素iv和sc的抗栓和抗凝作用。方法：按Chandler氏法由兔颈总动脉取血制备混合血栓和结扎大鼠下腔静脉制备静脉血栓模型；全血凝固时间(CT)按试管法测定，凝血酶时间(TT)、凝血酶原时间(PT)、活化的部分凝血活酶时间(APTT)和复钙时间(RT)均按常规方法测定。结果：iv时，LMWH组兔血栓重量低于等抗凝单位的肝素，对大鼠血栓重量的影响与等抗凝单位的肝素相似，对TT的延长作用弱于肝素，对CT，PT，APTT和RT的延长作用与肝素相似。sc时，LMWH组两种血栓模型的血栓重量均低于肝素组，而且对CT，PT，APTT，TT和RT的延长也明显强于肝素。结论：ivLMWH的抗栓作用强于肝素或与肝素相似，抗凝作用与肝素相似或较弱。sc时，LMWH的抗栓及抗凝作用均强于肝素。

Effects of LMWH and heparin by two administration routes on thrombosis and blood coagulation

OBJECTIVE: To investigate the effects of low molecular weight heparin (LMWH) and heparin injected intravenously and subcutaneously respectively on thrombosis and blood coagulation. METHODS: Two thrombus models were established according to Chandler's method and to Reyer's method. Clotting time (CT), prathrombin time (PT), thrombin time (TT), active partial thromboplastin time (APTT), and recalcification time (RT) were measured. RESULTS: When injected intravenously, the weight of thrombus in LMWH group was lighter than that of heparin at the same anticoagulant unit in Chandler's thrombosis model and similar to that of heparin in Reyers' model. LMWH could prolong the CT, PT, RT, APTT to the same extent as heparin, with the exception of TT which was shorter in LMWH group. When injected subcutaneously, the weight of thrombus in LMWH group was lighter than that of heparin both in Chandler's model and in Reyers' model. Furthermore, the CT, PT, APPT, TT and RT in LMWH group were longer than those of heparin. CONCLUSION: LMWH iv showed antithrombotic effect is more potent than heparin or at least similar to heparin, with the effect on blood coagulation weaker than heparin. When injected subscutaneously, the antithrombotic effects and anticoagulant effects of LMWH were more potent than those of heparin.