Harbauer G, Kettenring P
Department of Experimental Surgery, Saar University, Homburg/Saar, FRG.
Haemostasis. 1988;18 Suppl 3:64-8. doi: 10.1159/000215869.
Low-molecular-weight heparin (LMWH) derivatives differ among one another and from unfractioned heparin (UFH) in their half-life as well as in their mode of action. Our aim was to find out, whether the plasma activity levels and their time course after subcutaneous low-dose application of LMWH or UFH in the experimental rabbit are comparable to those in humans. Fairly reasonable standard curves for each LMWH preparation were obtained by using geometrical dilution series of spiked rabbit pool plasma and by applying the methods of Bartl et al. (anti-IIa) and Holmer et al. (anti-Xa). The latter method was slightly modified in order to achieve discernable photometric absorptions for activity levels less than 0.05 U/ml. Rabbits under intravenous general anesthesia received an anterior neck incision. The right external jugular vein was dissected free. A catheter was inserted, advanced into the upper caval vein and kept patent by continuous infusion of 10 ml/h of normal saline. Blood samples of 4 ml were collected in syringes containing 1 ml sodium citrate, before and 1, 2, 4 and 8 h after subcutaneous injection of a LMWH derivative or UFH. The samples were centrifuged and frozen to -30 degrees C. For the estimation of heparin-like anti-IIa and anti-Xa activities the samples were thawed and treated in the same manner as the samples from which the standard curves had been derived.(ABSTRACT TRUNCATED AT 250 WORDS)
低分子量肝素（LMWH）衍生物之间以及与普通肝素（UFH）在半衰期和作用方式上存在差异。我们的目的是探究，在实验兔皮下低剂量应用LMWH或UFH后，其血浆活性水平及其时间进程是否与人类相当。通过使用加标的兔混合血浆的几何稀释系列，并应用Bartl等人（抗IIa）和Holmer等人（抗Xa）的方法，为每种LMWH制剂获得了相当合理的标准曲线。为了使活性水平低于0.05 U/ml时能获得可分辨的光度吸收，对后一种方法进行了轻微修改。在静脉全身麻醉下的兔子接受颈部前方切口。游离出右颈外静脉。插入一根导管，推进到上腔静脉，并通过以10 ml/h的速度持续输注生理盐水来保持通畅。在皮下注射LMWH衍生物或UFH之前以及之后1、2、4和8小时，在含有1 ml柠檬酸钠的注射器中采集4 ml血样。将样品离心并冷冻至-30摄氏度。为了估计类肝素抗IIa和抗Xa活性，将样品解冻并以与绘制标准曲线所用样品相同的方式处理。（摘要截短于250字）
