Influence of Low Molecular Weight Heparin on the Hemostatic System After Abdominal Surgery

1985 ◽  
Vol 53 (03) ◽  
pp. 297-300 ◽  
Author(s):  
U Schmitz-Huebner ◽  
C Rüschemeyer ◽  
H Schulte ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Abdominal Surgery ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Total Blood ◽  
Treatment Groups ◽  
Hemostatic System ◽  
Heparin Fractions ◽  
Molecular Weight Fractions ◽  
Heparin Preparation

SummaryThe hemostatic effect of two low molecular weight heparin fractions and of one unfractionated heparin preparation administered subcutaneously b. i. d. was examined in 6 healthy subjects and in 53 patients after major abdominal surgery. Among other tests platelet count, prothrombin time, fibrinogen, β-thrombo- globulin, antithrombin, antiplasmin, FPA and F-CB 3 related antigen, as well as various heparin activities, were repeatedly determined pre- and postoperatively. Under all tested conditions the low molecular weight fractions induced higher heparin levels, both in terms of anti-Xa and of anti-thrombin activity. No further significant differences of the laboratory results between the treatment groups were documented. Total blood loss measured at the first postoperative day was higher in patients with malignancy and negatively correlated with antithrombin and antiplasmin levels, while no relation was observed with the heparin activities and the other tested parameters. Whereas evidence for a hemorrhagic property of the tested low molecular weight heparin fractions was found, a particular mechanism underlying this effect could not be identified.

Antithrombotic Properties Of Low Molecular Weight Heparin Fractions From Porcine Mucosal Heparin

1981 ◽  
Author(s):  
J Choay ◽  
Jean C Lormeau ◽  
Harry L Messmore ◽  
Jawed Fareed ◽  
J Stulc ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Prothrombin Complex Concentrate ◽  
Specific Activity ◽  
Weight Fraction ◽  
Low Molecular Weight ◽  
Prothrombin Complex Concentrates ◽  
Heparin Fractions ◽  
Russell’S Viper ◽  
Molecular Weight Fractions

A previous report from our laboratories has described the extraction and physicochemical properties of a low molecular weight fraction (mol wt 4-8 × 103 daltons) from porcine mucosal heparin (Choay et. al. thrombosis Res 18, 573, 1980). Beside exhibiting a strong anti Xa (>250 u/mg) activity, this product possessed strong antithrombotic properties in a modified rabbit stasis thrombosis model. At a 125 anti Xa u/kg it protected the thrombotic effects of activated prothrombin complex concentrate (20 u/kg) and Prothrombin Complex Concentrate/Russell’s Viper Venom challenge in both the pretreatment and post-treatment regiments. At 1250 anti Xa u/kg SC it also showed antithrombotic effects for various periods. We have also obtained another low molecular weight fraction from porcine mucosal heparin by controlled depolymerization with nitrous acid. This product possessed saccharides with molecular weight ranging 3-6 × 103 daltons and exhibited a specific activity of >200 anti Xa u/mg. At a 125 anti Xa u/kg this product also showed antithrombotic activity against the thrombotic effects of activated prothrombin complex concentrates, prothrombin complex concentrates and Russell’s Viper Venom. In contrast to these two low molecular weight fractions porcine mucosal heparin in identical anti Xa units failed to produce protection against the thrombogenic stimuli. Our studies suggest that low molecular weight heparin fractions with strong anti Xa and antithrombotic activities can be obtained by chemical depolymerization. Furthermore, their biologic properties are found to be similar to the naturally occuring low molecular weight fractions present in native porcine mucosal heparin.

In Vivo Studies On The Inhibition Of Coagulation By Fractionated Heparin

1981 ◽  
Author(s):  
U Schmitz-Huebner ◽  
L Balleisen ◽  
F Asbeck ◽  
J van de Loo
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Gel Filtration ◽  
In Vivo Studies ◽  
Low Molecular Weight ◽  
Chromogenic Substrate ◽  
Serotonin Content ◽  
Heparin Activity ◽  
Heparin Fractions

Recent investigations suggest that low molecular weight heparin may have advantages over conventional heparin with regard to the prevention of venous thrombosis and haemorrhagic side effects.High (HMW) and low (LMW) molecular weight heparin fractions with mean MWs of 16,000 and 8,800 respectively, obtained by gel filtration chromatography of sodium mucosal heparin (B. Braun Melsungen), were injected subcutaneously into six volunteers and compared with the unfractionated substance in a cross-over trial. Doses of 5,000 U were administered twice daily over a period of three days and heparin activity was controlled before injection and 2,4,8 hours afterwards by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of fractionated heparin on platelet function was examined. The results show that the LMW fraction induced markedly higher anti-Xa activity than the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the HMW fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA-production, while the LMW fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of PF IV, whereas the serotonin content of platelets determined at the same time increased.It is concluded that s.c. injections of LMW heparin induce relatively high levels of anti-Xa activity without leading to sensitive platelet activation or to major effects on overall clotting tests.

scholarly journals Removal of the anticoagulant activities of the low molecular weight heparin fractions and fragments with flavobacterial heparinase

1986 ◽  
Vol 44 (5) ◽  
pp. 599-610 ◽  
Author(s):  
Victor C. Yang ◽  
Howard Bernstein ◽  
Charles L. Cooney ◽  
Jill C. Kadam ◽  
Robert Langer
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Heparin Fractions
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