Thomas D P, Merton R E
Thromb Res. 1982 Nov 1;28(3):343-50. doi: 10.1016/0049-3848(82)90116-5.
A 6000 daltons low molecular weight heparin (LMWH) was compared with unfractionated mucosal heparin in vitro and in vivo. Despite unimpressive specifications by clotting assays in vitro, the LMWH gave high and sustained activity in vivo by anti-Factor Xa assays, following subcutaneous injection. However, activity measured by APTT and calcium thrombin time assays was at least as high as occurred following unfractionated heparin. On the basis of clotting assays, there seems no reason to expect a lower incidence of haemorrhagic side-effects following the clinical use of this LMWH. The study also strikingly demonstrates the inadequacy of in vitro clotting assays for assessing the in vivo behaviour of LMWH.
将一种6000道尔顿的低分子量肝素（LMWH）与未分级的黏膜肝素进行了体外和体内比较。尽管体外凝血试验的指标并不突出，但皮下注射后，通过抗Xa因子试验，低分子量肝素在体内具有高且持续的活性。然而，通过活化部分凝血活酶时间（APTT）和钙凝血酶时间试验测得的活性至少与未分级肝素后的活性一样高。基于凝血试验，似乎没有理由预期临床使用这种低分子量肝素后出血副作用的发生率会更低。该研究还显著表明体外凝血试验不足以评估低分子量肝素的体内行为。
