Interaction Between Low Molecular Weight Dextran Sulphate and Bentonite adsorbed Plasma

1979 ◽  
Author(s):  
T. Matsuda ◽  
M. Ogawara ◽  
T. Seki ◽  
R. Miura ◽  
M. Yokouchi ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antithrombin Iii ◽  
Low Molecular Weight ◽  
Thrombin Time ◽  
Dextran Sulphate ◽  
Bothrops Atrox ◽  
Plasmin Inhibitor ◽  
Mean Molecular Weight

Effects of low molecular weight dextran sulphate (D.S.; mean molecular weight = 6,0006,500; S content = 17-19%) and/or bentonite (Wako Pure Chemical Industries, Osaka, Japan) adsorbed plasma (supernatant from plasma mixed with 300 mg/ml of bentonite for 10 minutes at 37°C), which contains no fibrinogen nor antithrombin III but α2 macro-globulin, α1-antitrypsin and α2-plasmin inhibitor, on thrombin time or batroxobin (purified fraction of venom of Bothrops atrox) time of fibrinogen solution were investigated. Addition of D.S. or bentonite adsorbed plasma to fibrinogen solution resulted in prolongations of thrombin time and batroxobin time. These results indicate that both D.S. and bentonite adsorbed plasma inhibit conversion of fibrinogen to fibrin by thrombin or batroxobin. However, when appropriately diluted bentonite adsorbed plasma and D.S. were added to fibrinogen solution simultaneously, thrombin times and batroxobin times were shorter compared to those when either bentonite adsorbed plasma or D.S. but not both was added. From these results, it is concluded that D.S. and bentonite adsorbed plasma interact to inhibit each other.

Chrono-Pharmacological Study of Once Daily Curative Dose of a Low Molecular Weight Heparin (200IU antiXa/kg of Dalteparin) in Ten Healthy Volunteers

1995 ◽  
Vol 74 (02) ◽  
pp. 660-666 ◽  
Author(s):  
P Mismetti ◽  
J Reynaud ◽  
B Tardy-Poncet ◽  
S Laporte-Simitsidis ◽  
M Scully ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Healthy Volunteers ◽  
Low Molecular Weight Heparin ◽  
Pharmacological Study ◽  
Area Under The Curve ◽  
Factor Xa ◽  
Similar Efficacy ◽  
Low Molecular Weight ◽  
Thrombin Time ◽  
Once Daily

SummaryLow molecular weight heparin (LMWH) is currently prescribed for the treatment of deep vein thrombosis at the dose of 100 IU antiXa/kg twice daily or at a dose of 175 IU antiXa/kg once daily with a similar efficacy. We decided to study the chrono-pharmacology of curative dose of LMWH once daily administrated according to the one previously described with unfractionated heparin (UFH).Ten healthy volunteers participated in an open three-period crossover study according to three 24 h cycles, separated by a wash-out interval lasting 7 days: one control cycle without injection, two cycles with subcutaneous injection of 200 IU antiXa/kg of Dalteparin (Fragmin®) at 8 a.m. or at 8 p.m. Parameters of heparin activity were analysed as maximal values and area under the curve.Activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT) and tissue factor pathway inhibitor (TFPI) were higher after 8 p.m. injection than after 8 a.m. injection (p <0.05) while no chrono-pharmacological variation of anti factor Xa (AXa) activity was observed. Thus the biological anticoagulant effect of 200 IU antiXa/kg of Dalteparin seems to be higher after an evening injection than after a morning injection.A chrono-therapeutic approach with LMWH, as prescribed once daily, deserves further investigation since our results suggest that a preferential injection time may optimise the clinical efficacy of these LMWH.

Covalent Complexes Between Low Molecular Weight Heparin Fragments and Antithrombin III – Inhibition Kinetics and Turnover Parameters

1983 ◽  
Vol 49 (02) ◽  
pp. 109-115 ◽  
Author(s):  
M Hoylaerts ◽  
E Holmer ◽  
M de Mol ◽  
D Collen
Keyword(s):  
Molecular Weight ◽  
Half Life ◽  
Low Molecular Weight Heparin ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Life Time ◽  
Low Molecular Weight ◽  
High Affinity ◽  
Plasma Half Life ◽  
Covalent Complex

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).

Characterisation of Persistent Anti-Xa Activity Following Administration of the Low Molecular Weight Heparin Enoxaparin Sodium (Clexane)

1994 ◽  
Vol 72 (02) ◽  
pp. 275-280 ◽  
Author(s):  
David Brieger ◽  
Joan Dawes
Keyword(s):  
Molecular Weight ◽  
Enoxaparin Sodium ◽  
Antithrombin Iii ◽  
Anticoagulant Activity ◽  
Active Material ◽  
Biologically Active ◽  
Size Exclusion ◽  
Low Molecular Weight ◽  
Exclusion Chromatography ◽  
Liver And Kidney

SummaryIt is widely reported that persistent anti-Xa activity follows administration of low molecular weight heparins. To identify the effectors of this activity we have injected 125I-labelled Enoxaparin sodium into rabbits and subsequently analysed the circulating radiolabelled material and anti-Xa activity by affinity and size exclusion chromatography. Antithrombin III-binding material derived from the injected drug was responsible for all the anti-Xa amidolytic activity. At early times after injection additional anticoagulant activity which was largely attributable to tissue factor pathway inhibitor was measured by the Heptest clotting assay after removal of glycosaminoglycans from plasma samples. Small radiolabelled fragments, including penta/hexasaccharide with affinity for antithrombin III, were detectable in the circulation 1 week later, and sulphated oligosaccharides persisted for 3-4 weeks. Significant quantities of radiolabel remained in the liver and kidney several weeks post-injection; these organs may sequester some of the injected drug and give rise to circulating biologically active material by degradation and secretion of catabolic products into the plasma.

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.

A COMPARISON OF THE BINDING OF ANTITHROMBIN III AND HEPARIN COFACTOR II TO HEPARINS, NATURALLY OCCURRING GLYCOSAMINOGLYCANS AND OTHER SULPHATED POLYMERS

1987 ◽  
Author(s):  
J Dawes ◽  
D S Pepper
Keyword(s):  
Molecular Weight ◽  
Chain Length ◽  
Antithrombin Iii ◽  
Molar Ratio ◽  
Heparin Binding ◽  
Dextran Sulphate ◽  
Heparin Cofactor Ii ◽  
Wide Range ◽  
Pentosan Polysulphate ◽  
Binding Sequence

Antithrombin III (ATIII) and heparin cofactor II (HCII) are currently thought to be the most important protein mediators of the anticoagulant and antithrombotic activities of glycosamino-glycans. A simple, quantitative method for assessing the affinity of a protein for a sulphated polymer in the liquid phase, based on competition with immobilised heparin, has been developed. Using this technique, the binding of ATIII and HCII to a wide range of glycosaminoglycans and other sulphated polymers have been compared, and the contributions to binding of size, degree of sulphation and backbone structure of the polymers analysed.In the presence of the high protein concentrations found in plasma, unfractionated heparin inhibited the binding of ATIII to immobilised heparin with a Ki of 1 x 10-6. Binding was destroyed by N-desulphation. 1 Results with a range of low molecular weight (LMW) heparins and heparan sulphates are consistent with the view that they all contain the ATIII-binding sequence, but at a lower molar ratio than heparin. Highly sulphated synthetic polymers such as dextran sulphate bound ATIII by a different mechanism, which was molecular weight-dependent.The affinity of HCII for heparins increased markedly with heparin chain length. Binding was largely, but not entirely, mediated by sulphate residues. HCII bound to heparan and dermatan sulphates with lower affinities than to heparin, and to synthetic sulphated polymers with similar or higher affinities. Pentosan polysulphate (SP54) bound HCII as effectively as did heparin. Binding of HCII to dextran sulphate was highly dependent on molecular weight. The affinity of HCII for a sulphated polymer appears to depend both on its chain length and density of sulphation.Thus the profiles of binding of ATIII and HCII to glycosaminoglycans and other sulphated polymers are quite different. This technique is useful both for investigating the interactions of existing therapeutic anticoagulants and assessing new products.

NEUTRALIZING EFFECT OF PLATELET FACTOR 4 OR HISTIGINE-RICH GLYCOPROTEIN AGAINST LOW MOLECULAR WEIGHT HEPARIN AND UNFRACTIONATED HEPARIN

1987 ◽  
Author(s):  
K Takahashi ◽  
M Niwa ◽  
N Sakuragawa
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Antithrombin Iii ◽  
Platelet Factor 4 ◽  
Low Molecular Weight ◽  
Bleeding Tendency ◽  
Human Origin ◽  
Platelet Factor ◽  
At Iii ◽  
Antifactor Xa

Purpose: Low molecular weight(LMW) heparin shows stronger antifactor Xa(F-Xa) and weaker anti-thrombin(TH) activities compared with unfractionated(UF) heparin, and shows less bleeding tendency in the cases of clinical use. Platelet factor 4(Pf-4) and histidine-rich glycoprotein(HRG) neutralize heparin. We investigated on the heparin neutralizing effects of them to both kinds of heparinMaterials and methods: LMW heparin(Kabi and Pharmuka) and UF heparin(Novo) were used. Antithrombin III(AT-III), HRG(human origin ) and pf-4( bovine origin ) were purified by our methodsTH(Green-Cross) and F-Xa(Sigma) were used. Reaction mixtures for anti-TH or anti-F-Xa were as follows: 1 vol of AT-III( 0.1 U/ml)+ 1 vol of heparin( 10 ug/ml)+l vol of pf-4 or HRG(varied)→incubated for 5 min→+l vol of TH(5 U/ml) or F-Xa( 7 nKat/ml)→incubated for 5 min→ + S-2238 or S-2222→ recorded at 405 nm.Results: (1) Pf-4 showed the equivalent anti-TH effect on both kinds of heparin, and 3 ug of pf-4 neutralized 1 ug of heparinOn F-Xa neutralizing effect, 13 ug of pf-4 neutralized 1 ug of UF heparin, but could not neutralize LMW heparin. (2) HRG showed the same results on anti-TH effect of both kinds of heparin, but could not neutralize the anti-F-Xa effect of LMW heparin on the same amount of HRG which neutralized that of UF heparin. Conclusion: Anti-F-Xa effect of. LMW heparin could not be easily neutralized by pf-4 or HRG compared with that of UF heparin.

In Vitro Characterization Of Low Molecular Weight Fractions Of Heparin

1981 ◽  
Author(s):  
Jawed Fareed ◽  
Harry L Messmore ◽  
Daniel A Walz ◽  
Jean Choay ◽  
J C Lormeau
Keyword(s):  
Molecular Weight ◽  
The Other ◽  
Low Molecular Weight ◽  
In Vitro Test ◽  
Thrombin Time ◽  
Specific Test ◽  
Platelet Factor ◽  
At Iii ◽  
Heparin Fractions

Numerous extraction, chromatographic (ion exchange, gel, and affinity), chemical and enzymatic degradation methods have been employed to obtain heparin fractions. The present assays to evaluate potency (e.g. pharmacopeial and coagulant) do not truly reflect the antithrombotic properties of these fractions. In addition, the synthetic peptide substrate based assays to measure the anti Xa activity do not correlate with the coagulant anti Xa assays. We have developed an in vitro test battery to evaluate low molecular weight heparin fractions. Porcine mucosal heparin fractions are assayed for anti Xa activity in coagulant and amidolytic assays and the results are expressed as a ratio. The effect of these fractions on coagulant assays such as prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), Stypven time (ST) on freshly prepared normal human plasma (NHP) is determined The retention characteristics of these fractions on platelet factor 4 and AT-III bound sepharose columns were also determined. We have compared the extracted and chemically depolymerized heparin fractions and found that the anti Xa activity doesn’t always correlate with the other parameters studied. The extracted fractions were slightly stronger in the USP assays and showed a biphasic retention on the PF-4 column whereas the chemically depolymerized product showed only one peak. On the other hand, on the AT-III column both fractions showed similar elution patterns. Our studies suggest that heparin and its fractions exhibit differential behavior on various assays and a specific test may not be used as an index of the potency of their antithrombotic effects. Furthermore, the potency of these fractions should be stated on a weight basis when evaluated in the in vivo animal models rather than in terms of a specific test (e.g. anti Xa activity and US Pharmacopeial assays).

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