scholarly journals On the Relationship Between Molecular Mass and Anticoagulant Activity in a Low Molecular Weight Heparin (Enoxaparin)

1992 ◽  
Vol 67 (05) ◽  
pp. 556-562 ◽  
Author(s):  
Ana-Victoria Bendetowicz ◽  
Elisabeth Pacaud ◽  
Suzette Béguin ◽  
André Uzan ◽  
H Coenraad Hemker
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Low Molecular Weight Heparin ◽  
Anticoagulant Activity ◽  
Low Molecular Weight ◽  
Gel Chromatography ◽  
Molecular Weights ◽  
Thrombin Inhibition ◽  
Specific Catalytic Activity ◽  
The Relationship

SummaryA low molecular weight heparin (enoxaparin, mean molecular weight ~ 4,400) was separated by gel chromatography into eight different fractions with a narrow distribution around the following mean molecular weights: 1,800, 2,400, 2,900, 4,200, 6,200, 8,600, 9,800 and 11,000. We compared the influence of enoxaparin on the generation of thrombin in plasma to that of the eight fractions.We determined: a) the % of material with high affinity to antithrombin III (HAM) and the % of HAM above the critical chainlength necessary to allow for thrombin inhibition (ACLM), b) the specific catalytic activity on the decay of endogenous thrombin, and c) the inhibition of over-all thrombin formation in the extrinsic and the intrinsic pathway. From b and c we calculated the inhibition of prothrombin conversion in these pathways.We found that a) there is a gradual decrease of the HAM fraction with decreasing molecular weight; b) the specific catalytic activity for the inactivation of thrombin does not vary significantly between the fractions when expressed in terms of ACLM; c) the potency to inhibit prothrombin conversion does not vary significantly between the fractions when expressed in terms of HAM.

Comparison of the Non-Specific Binding of Unfractionated Heparin and Low Molecular Weight Heparin (Enoxaparin) to Plasma Proteins

1993 ◽  
Vol 70 (04) ◽  
pp. 625-630 ◽  
Author(s):  
Edward Young ◽  
Benilde Cosmi ◽  
Jeffrey Weitz ◽  
Jack Hirsh
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Plasma Proteins ◽  
Low Molecular Weight Heparin ◽  
Specific Binding ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Low Molecular Weight ◽  
Heparin Binding ◽  
Fixed Amount

SummaryThe non-specific binding of anticoagulantly-active heparin to plasma proteins may influence its anticoagulant effect. We used low affinity heparin (LAH) essentially devoid of anti-factor Xa activity to investigate the extent and possible mechanism of this non-specific binding. The addition of excess LAH to platelet-poor plasma containing a fixed amount of unfractionated heparin doubled the anti-factor Xa activity presumably because it displaces anticoagulantly-active heparin from plasma proteins. Although dextran sulfates of varying molecular weights also increased the anti-factor Xa activity, less sulfated heparin-like polysaccharides had no effect. These findings suggest that the ability to displace active heparin from plasma protein binding sites is related to charge and may be independent of molecular size. In contrast to its effect in plasma containing unfractionated heparin, there was little augmentation in anti-factor Xa activity when LAH was added to plasma containing low molecular weight heparin (LMWH), indicating that LMWH binds less to plasma proteins than unfractionated heparin. This concept is supported by studies comparing the anticoagulant activity of unfractionated heparin and LMWH in plasma with that in buffer containing antithrombin III. The anti-factor Xa activity of unfractionated heparin was 2-fold less in plasma than in the purified system. In contrast, LMWH had identical anti-factor Xa activity in both plasma and buffer, respectively. These findings may be clinically relevant because the recovered anti-factor Xa activity of unfractionated heparin was 33% lower in plasma from patients with suspected venous thrombosis than in plasma from healthy volunteers. The reduced heparin recovery in patient plasma reflects increased heparin binding to plasma proteins because the addition of LAH augmented the anti-factor Xa activity. In contrast to unfractionated heparin, there was complete recovery of LMWH added to patient plasma and little increase of anti-factor Xa activity after the addition of LAH. These findings may explain why LMWH gives a more predictable dose response than unfractionated heparin.

scholarly journals Anticoagulant Properties of a Green Algal Rhamnan-type Sulfated Polysaccharide and Its Low-molecular-weight Fragments Prepared by Mild Acid Degradation

Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 445 ◽  
Author(s):  
Xue Liu ◽  
Peng Du ◽  
Xiao Liu ◽  
Sujian Cao ◽  
Ling Qin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Anticoagulant Activity ◽  
Sulfated Polysaccharide ◽  
Low Molecular Weight ◽  
Thrombin Time ◽  
Acid Degradation ◽  
Molecular Weights ◽  
Green Algal

The active sulfated polysaccharide from seaweed possesses important pharmaceutical and biomedical potential. In the study, Monostroma sulfated polysaccharide (MSP) was obtained from Monostroma angicava, and the low-molecular-weight fragments of MSP (MSP-Fs: MSP-F1–MSP-F6) were prepared by controlled acid degradation. The molecular weights of MSP and MSP-F1–MSP-F6 were 335 kDa, 240 kDa, 90 kDa, 40 kDa, 24 kDa, 12 kDa, and 6.8 kDa, respectively. The polysaccharides were sulfated rhamnans that consisted of →3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→ units with partial sulfation at C-2 of →3)-α-l-Rhap-(1→ and C-3 of →2)-α-l-Rhap-(1→. Anticoagulant properties in vitro of MSP and MSP-F1–MSP-F6 were evaluated by studying the activated partial thromboplastin time, thrombin time, and prothrombin time. Anticoagulant activities in vivo of MSP and MSP-F4 were further evaluated; their fibrin(ogen)olytic activities in vivo and thrombolytic properties in vitro were also assessed by D-dimer, fibrin degradation products, plasminogen activator inhibitior-1, and clot lytic rate assays. The results showed that MSP and MSP-F1–MSP-F4 with molecular weights of 24–240 kDa had strong anticoagulant activities. A decrease in the molecular weight of MSP-Fs was accompanied by a decrease in the anticoagulant activity, and higher anticoagulant activity requires a molecular weight of over 12 kDa. MSP and MSP-F4 possessed strong anticoagulant activities in vivo, as well as high fibrin(ogen)olytic and thrombolytic activities. MSP and MSP-F4 have potential as drug or helpful food supplements for human health.

scholarly journals Effect of myeloperoxidase on the anticoagulant activity of low molecular weight heparin and rivaroxaban in an in vitro tumor model

2020 ◽  
Vol 18 (12) ◽  
pp. 3267-3279
Author(s):  
Minna Voigtlaender ◽  
Lennart Beckmann ◽  
Anita Schulenkorf ◽  
Bianca Sievers ◽  
Christina Rolling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Anticoagulant Activity ◽  
Tumor Model ◽  
Low Molecular Weight

The Additive Effect of Low Molecular Weight Heparins on Thrombin Inhibition by Dermatan Sulfate

1993 ◽  
Vol 70 (03) ◽  
pp. 443-447 ◽  
Author(s):  
Benilde Cosmi ◽  
Giancarlo Agnelli ◽  
Edward Young ◽  
Jack Hirsh ◽  
Jeffrey Weitz
Keyword(s):  
Molecular Weight ◽  
Antithrombin Iii ◽  
Dermatan Sulfate ◽  
Anticoagulant Activity ◽  
Additive Effect ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Heparin Cofactor Ii ◽  
Thrombin Inhibition ◽  
Sds Page

SummaryThe aim of this study was to investigate the mechanism by which the anticoagulant activity of dermatan sulfate (DS) is increased by low molecular weight heparin (LMWH). In platelet poor plasma, LMWH enhances the effect of DS on thrombin (IIa) inhibition as determined by thrombin clotting times and with a chromogenic substrate assay. Analysis of the results of the chromogenic assays using either the algebraic fractional or the graphic isobole method suggests that LMWH has an additive effect on the anti-IIa activity of DS. This additive effect was lost when the experiments were repeated in plasma immunodepleted of antithrombin III (ATIII), indicating that the anti-IIa activity of LMWH is ATIII-dependent. To further explore the mechanism of the interaction between LMWH and DS, 125I-labeled IIa was added to plasma in the presence or absence of DS and/or LMWH and the formation of IIa-inhibitor complexes was assessed using SDS-PAGE followed by autoradiography. DS addition selectively increases the formation of heparin cofactor II (HCII)-IIa complexes, whereas LMWH enhances ATIII-IIa complex generation. Compared to plasma containing DS alone, the formation of ATIII-IIa complexes also is increased when the combination of DS and LMWH is added. These findings suggest that the additive effect of LMWH on the anti-IIa activity of DS reflects their different modes of IIa inhibition; DS potentiates IIa inhibition by HCII, while LMWH catalyses ATIII-dependent IIa inactivation. The potential clinical significance of these findings requires further investigation.

An International Standard for Low Molecular Weight Heparin

1988 ◽  
Vol 60 (01) ◽  
pp. 001-007 ◽  
Author(s):  
T W Barrowcliffe ◽  
A D Curtis ◽  
E A Johnson ◽  
D P Thomas
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Collaborative Study ◽  
Low Molecular Weight ◽  
International Standard ◽  
Thrombin Inhibition ◽  
Interlaboratory Variability ◽  
Assay Methods ◽  
The Mean ◽  
International Collaborative Study

SummaryAn international collaborative study has been carried out with the aim of establishing an international standard for low molecular weight (LMW) heparin. Three preparations of LMW heparin were assayed against the International Standard for unfractionated heparin (UFH) by 25 laboratories in 13 countries, using nine different assay methods. The results confirmed previous findings of non-parallel assays, wide interlaboratory variability and differences between methods when LMW heparins are assayed against a UFH standard. Use of one of the LMW heparins as a standard for the other two gave parallel assays and much closer agreement between laboratories. The preparation in ampoules coded 85/600 was selected as likely to give the best agreement with the largest number of LMW heparins; potencies were assigned by taking the mean of all the anti-Xa assays, and the mean of the thrombin and APTT assays, to represent the two major groups of activities. Preparation 85/600 has been established by WHO as the 1st International Standard for LMW heparin, with potencies of 1,680 iu/ampoule by anti-Xa assays and 665 iu/ampoule by thrombin inhibition and APTT assays.

Low Molecular Weight Heparin Is Responsible for the Anti-Xa Activity of Desmin 370

1996 ◽  
Vol 75 (02) ◽  
pp. 286-291 ◽  
Author(s):  
David Brieger ◽  
Joan Dawes
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Dermatan Sulphate ◽  
Molecular Weight Range ◽  
Sulphated Glycosaminoglycan

SummaryDermatan sulphate does not catalyse the inactivation of factor Xa. However, the low molecular weight (LMW) dermatan sulphate Desmin 370 has been shown to generate circulating anti-Xa activity following administration to humans. Using a single batch of Desmin 370, we measured 3 U/mg of anti-Xa activity by amidolytic assay in vitro. The material responsible for this activity had a lower molecular weight range (6000 and 1800 Da) than Desmin 370 and was more highly sulphated than the bulk of the drug. Heparinase digestion of Desmin 370 eliminated 90% of the in vitro anti-Xa activity without significantly interfering with its ability to potentiate inactivation of thrombin by HCII, suggesting that the anti-Xa activity is not due to dermatan sulphate and is probably heparin. When 125I-labelled Desmin 370 together with 40 mg/kg carrier drug was administered intravenously to a rabbit, anti-Xa activity was readily detectable in the plasma for up to 10 h and had a longer half-life than the sulphated radiolabel. Most of this anticoagulant activity was recovered from the plasma by Polybrene affinity chromatography and was probably a sulphated glycosaminoglycan. Administration of the heparinase-digested drug to a rabbit resulted in 70% less anti-Xa activity than the undigested drug. We conclude that Desmin 370 contains detectable quantities of biologically active low molecular weight heparin, which is responsible for persistent anti-Xa activity following intravenous administration.

Molecular Weight Measurements of Low Molecular Weight Heparins by Gel Permeation Chromatography

1997 ◽  
Vol 77 (04) ◽  
pp. 668-674 ◽  
Author(s):  
B Mulloy ◽  
C Gee ◽  
S F Wheeler ◽  
R Wait ◽  
E Gray ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Molecular Weights ◽  
Calibration Table ◽  
Gel Permeation ◽  
Degraded Material

SummaryThe molecular weight profiles of low molecular weight heparin samples have been measured by high-performance gel permeation chromatography using as calibrant the heparinase-degraded material (90/686) now established as the 1st International Reference Preparation (IRP) Low Molecular Weight Heparin for Molecular Weight Calibration. Use of the calibrant as a broad molecular weight standard is described and a calibration table provided based on data collected over several years in one laboratory.In order to confirm the assignment of degree of polymerisation to resolved oligosaccharide peaks in the calibrant, molecular weights of oligosaccharides fractionated from the 1st IRP were independently determined by fast atom bombardment mass spectrometry (FAB MS).The molecular weight distributions of commercial low molecular weight heparins have been characterized. Measurements of molecular weight parameters of heparin molecular weight standards from several sources provide comparisons between the molecular weight scales of this and other studies.

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