fondaparinux and Disease-Models--Animal

Topics: Acute Disease; Animals; Anticoagulants; Clinical Trials as Topic; Disease Models, Animal; Drug Evaluation, Preclinical; Drug Interactions; Drug Therapy, Combination; Factor Xa Inhibitors; Fibrinolytic Agents; Fondaparinux; Humans; Injections, Subcutaneous; Polysaccharides; Pulmonary Embolism; Venous Thrombosis

Considering that fibrin deposition is observed in glomerulonephritis as well as in diabetic nephropathy, we performed studies to clarify the roles of the coagulation pathway and the active type of coagulation factor X (factor Xa) in the development of chronic kidney disease (CKD) using animal models. Factor Xa activates various cell types through protease-activated receptor 2 (PAR2). Several in vitro studies have demonstrated that PAR2 can mediate factor Xa signaling, but not thrombin signaling. Coagulation processes proceed together with the extracellular matrix (ECM) accumulation through factor V expression in rat Thy-1 nephritis. DX-9065a, a factor Xa inhibitor, suppresses this type of glomerulonephritis. The factor Xa inhibitor danaparoid ameliorated proteinuria, cellular proliferation, and fibrin deposition in lipopolysaccharide (LPS)-triggered activation of High IgA (HIGA) strain of ddY mice. Another factor Xa inhibitor, fondaparinux, suppressed urinary protein, glomerular hypertrophy, and connective tissue growth factor (CTGF), and ECM protein deposition together with angiogenesis in diabetic db/db mice. Finally, in the model of peritoneal fibrosis, fondaparinux treatment decreased the thickness of submesothelial fibrotic tissue and angiogenesis. In consideration of the results to potential human therapy, factor Xa regulation may be promising for the treatment of the aggravation in glomerulonephritis and of the early phase of diabetic nephropathy. In the near future, novel factor Xa inhibitors with the characteristics of oral administration and biliary elimination may appear in the clinical use for treatment of cardiovascular diseases.

Topics: Animals; Blood Coagulation; Disease Models, Animal; Extracellular Matrix; Factor V; Factor Xa; Factor Xa Inhibitors; Fondaparinux; Humans; Mice; Molecular Targeted Therapy; Naphthalenes; Polysaccharides; Propionates; Proteinuria; Rats; Receptor, PAR-2; Renal Insufficiency, Chronic; Signal Transduction

There is in vitro and in vivo evidence that anticoagulants impair normal bone metabolism, and it is widely believed that this may impair fracture healing. However, there are only a few heterogeneous in vivo animal studies confirming this and the mechanisms are not fully understood.. To review the literature concerning the effects of anticoagulants on fracture healing, and to present current understanding of the mechanisms involved by reviewing in vivo studies of bone biology and in vitro studies of bone cells.. A systematic search of Medline and other databases was combined with manual searching of bibliographies of key papers to identify relevant studies in the English and German languages.. There is strong evidence that warfarin, heparin and aspirin retard fracture healing. The preferential use of low molecular weight heparins is advocated to minimise this. Fondaparinux has not shown any impairment in vitro. Further studies of fondaparinux, the timing of anticoagulation therapy and the mechanisms of action of these agents are of paramount importance.

Topics: Animals; Anticoagulants; Aspirin; Bone and Bones; Bone Remodeling; Disease Models, Animal; Fondaparinux; Fracture Healing; Heparin; Humans; Polysaccharides; Warfarin

Fondaparinux (FDX) was demonstrated to be cardioprotective in a rat model of myocardial ischemia reperfusion. In this model, FDX reduced infarct size after 2h of reperfusion, involving the activation of the survivor activating factor enhancement (SAFE) pathway as early as 30min post-reperfusion. Our aim was to study if this cardioprotection could be explained by anti-inflammatory mechanisms and a protective effect on vessels.. Wistar male rats were subjected to 40minutes (min) of myocardial ischemia, followed by 30min or 2h of reperfusion. Rats were randomized into four groups: control 30min (n=7), FDX 30min (n=7), control 2h (n=7), and FDX 2h (n=7). The FDX groups received 10mg/kg injection of FDX 10min prior to initiating reperfusion. We studied: 1) mRNA expression of endothelial markers, such as thrombomodulin (TM), endothelial protein C receptor (EPCR), and tissue factor (TF) and 2) proteic expression of ICAM-1, NF-κB, IκB, and JNK. Leukocyte infiltration was assessed by histochemistry. We also evaluated TM and EPCR mRNA expression in a model of isolated rat mesenteric arteries incubated with FDX.. FDX upregulated the expression of TM and EPCR mRNA in the models of myocardial infarction and isolated mesenteric arteries. No difference was observed between the treated and control groups regarding the expression of pro-inflammatory signaling proteins, adhesion molecules, and leukocyte infiltration after 2h of reperfusion.. The cardioprotective effect of FDX at early-stage reperfusion could be related to vascular protection, yet not to an anti-inflammatory effect.

Topics: Animals; Anticoagulants; Cardiotonic Agents; Disease Models, Animal; Fondaparinux; Male; Mesenteric Arteries; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Polysaccharides; Rats; Rats, Wistar; Receptors, Endothelin; RNA, Messenger; Thrombomodulin; Up-Regulation

Atherosclerosis is a progressive inflammatory disease that can lead to sudden cardiac events by plaque rupture and subsequent thrombosis. Factor Xa (FXa) not only occupies a crucial position in the coagulation cascade responsible for thrombin generation, but also has pro-inflammatory effects. The hypothesis that Fondaparinux, the selective FXa inhibitor, attenuates plaque progression and promotes stability of atherosclerotic lesions was assessed.. Fondaparinux (5 mg/kg body weight/day) or 0.9% saline was intraperitoneally administered for 4 weeks to apolipoprotein E-deficient mice (n=12 per group) with established atherosclerotic lesions in the innominate arteries. Fondaparinux did not remarkably decrease the progression of atherosclerosis development in apolipoprotein E-deficient mice, but increased the thickness of fibrous cap (P=0.049) and decreased the ratio of necrotic core (P=0.001) significantly. Moreover, Fondaparinux reduced the staining against Mac-2 (P=0.017), α-SMA (P=0.002), protease-activated receptor (PAR)-1 (P=0.001), PAR-2 (P=0.003), CD-31 (P=0.024), MMP-9 (P=0.000), MMP-13(P=0.011), VCAM-1 (P=0.041) and the mRNA expression of inflammatory mediators (P<0.05) significantly, such as interleukin (IL)-6, MCP-1, IFN-γ, TNF-α, IL-10 and Egr-1.. Fondaparinux, the selective FXa inhibitor, can promote the stability of atherosclerotic lesions in apolipoprotein E-deficient mice, possibly through inhibiting expression of the inflammatory mediators in plaque and reduced synthesis of MMP-9 and MMP-13.

Topics: Animals; Apolipoproteins E; Atherosclerosis; Blood Coagulation; Brachiocephalic Trunk; Cytokines; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Factor Xa Inhibitors; Fibrosis; Fondaparinux; Inflammation Mediators; Male; Matrix Metalloproteinase 13; Matrix Metalloproteinase 9; Mice, Knockout; Necrosis; Plaque, Atherosclerotic; Polysaccharides; Time Factors

Myocarditis is induced by coxsackievirus B3 (CVB3). Myocardial inflammation is tied to the activation of coagulation. Coagulation factor (F) Xa, a central player in coagulation, activates matrix metalloproteinases (MMP), which modulate the remodeling.. In this study, we investigated the effects of pharmacological FXa inhibition on myocardial function, inflammation, and remodeling during a CVB3-induced myocarditis.. Immune cells and matrix proteins were detected by immunohistochemistry. The expression of cytokines was measured by real-time PCR and the activity of MMP-2 by zymography. Left ventricular function was analyzed using microconductance pressure catheter. Treatment with the FXa inhibitor fondaparinux led to an improved left ventricular function in CVB3-induced mice compared to saline-treated controls (dPdtmax: fondaparinux 4632 ± 499.6 vs. saline 3131 ± 374.0 [mmHg/s], P = 0.0503; SV: fondaparinux 33.19 ± 4.893 vs. saline 19.32 ± 2.236 [μL], P < 0.118; CO: fondaparinux 15124 ± 2183 vs. saline 8088 ± 1035 [μL/min], P < 0.05). Therapy with fondaparinux reduced the activity of MMP-2 (fondaparinux 1.208 ± 0.1247 vs. saline 1.565 ± 0.05476, P < 0.05). The collagen type I/III ratio as well as the expression of TIMP-1 was comparable in both infection groups postinfectionem (p.i.), despite an increased infiltration of macrophages into the hearts of mice treated with fondaparinux 8 days p.i. (CD68+: fondaparinux 494.2 ± 64.73 vs. saline 306.9 ± 43.73 [cells/mm(2) ], P < 0.05). Anti-inflammatory CD206-positive M2-type macrophages were increased in the infected hearts after fondaparinux treatment (CD206+: fondaparinux 182.1 ± 18.18 vs. saline 111.6 ± 21.07 [cells/mm(2) ], P < 0.05), whereas CD80-positive M1-type macrophages were comparable in both groups.. In conclusion, selective inhibition of FXa improves the left ventricular function during CVB3-induced myocarditis and seems to be associated with an improved myocardial remodeling.

Topics: Animals; Coxsackievirus Infections; Cytokines; Disease Models, Animal; Enterovirus B, Human; Factor Xa; Factor Xa Inhibitors; Fondaparinux; Inflammation Mediators; Male; Matrix Metalloproteinase 2; Mice, Inbred C57BL; Myocarditis; Polysaccharides; RNA, Messenger; Ventricular Function, Left; Ventricular Remodeling; Viral Load

Edoxaban is an oral and direct activated factor X inhibitor. In this study, the acute treatment effect of edoxaban on venous thrombosis is investigated in rats by single and multiple administrations, and compared to the conventional parenteral anticoagulants, enoxaparin and fondaparinux. Venous thrombus was induced in the inferior vena cava by partial stenosis plus topical application of 10% ferric chloride for 5min. After 1-h thrombus maturation, oral edoxaban and subcutaneous enoxaparin and fondaparinux were given. In the single administration experiment, thrombus weight was measured 1 or 4h after thrombus induction. In the multiple administration experiments, edoxaban was orally administered once daily (QD) and twice daily (BID) for 3 days. In the single administration experiment, oral administration of edoxaban (3.0 and 10mg/kg) 1h after thrombus formation significantly regressed the venous thrombus compared to the thrombus at 1h after thrombus formation. Similarly the significant venous thrombus regression was observed with enoxaparin (10mg/kg) and fondaparinux (0.30-3.0mg/kg). In the multiple administration experiment, both QD and BID administration of edoxaban at daily doses of 5 and 10mg/kg exerted significant treatment effects. QD administration of edoxaban including lower doses (1-10mg/kg) significantly reduced thrombus weight. Edoxaban administered QD and BID was effective in the treatment of venous thrombosis, and the treatment effect of edoxaban was comparable to the conventional parenteral anticoagulants. These data demonstrate the potential of edoxaban as an oral anticoagulant in the acute treatment of venous thromboembolism.

Topics: Administration, Oral; Animals; Anticoagulants; Antithrombin III; Disease Models, Animal; Drug Administration Schedule; Enoxaparin; Factor Xa Inhibitors; Fondaparinux; Male; Peptide Hydrolases; Polysaccharides; Pyridines; Rats; Rats, Wistar; Thiazoles; Venous Thrombosis

As a potent anticoagulant agent, fondaparinux exposes a risk of bleeding. An effective way to reverse its effects is needed. It was the objective to study efficacy and safety of prothrombin complex concentrate (PCC) to reverse the anticoagulant effect of fondaparinux in a rabbit model of bleeding and thrombosis. In anaesthetised and ventilated rabbits, the Folts model was applied: a stenosis (75%) and an injury were carried out on the carotid artery, inducing thrombosis. Blood flow decreased as thrombus size increased until the pressure gradient was such that the thrombus was released and local blood flow was suddenly restored. This is known as a cyclic flow reduction (CFR). After the first CFR, rabbits were randomised into three groups: control (saline and saline after 1 minute), fondaparinux (fondaparinux [3 mg.kg-1] and saline), PCC (fondaparinux and PCC [40 UI.kg-1]). Then CFRs were recorded over 20 minutes. The following were measured: ear immersion bleeding time (BT), haemoglobin blood level (Hb1) and thrombelastometric parameters (ROTEM®). Finally, a hepatosplenic section was performed; 15 minutes later, the amount of blood loss was recorded as primary endpoint and Hb2 was measured. Blood loss was increased with fondaparinux and normalised with PCC. Regarding ROTEM® INTEM, fondaparinux increased clotting time and clotting formation time. PCC normalised these parameters. EXTEM and FIBTEM tests were not modified. Regarding safety, PCC did not increase CFRs. PCC reduced bleeding without increasing thrombosis and was effective to reverse the haemorrhagic effect of fondaparinux in this rabbit model.

Topics: Animals; Anticoagulants; Blood Coagulation Factors; Carotid Arteries; Disease Models, Animal; Fondaparinux; Hemorrhage; Polysaccharides; Rabbits; Regional Blood Flow; Thrombosis; Treatment Outcome

In patients undergoing percutaneous coronary intervention, catheter thrombosis is more frequent with fondaparinux than heparin. This study was undertaken to identify the responsible mechanism and to develop strategies for its prevention. Percutaneous coronary intervention catheter segments shortened plasma clotting times from 971 ± 92 to 352 ± 22 seconds. This activity is factor XII (fXII) dependent because it was attenuated with corn trypsin inhibitor and was abolished in fXII-deficient plasma. Heparin and enoxaparin blocked catheter-induced clotting at 0.5 and 2 anti-Xa U/mL, respectively, whereas fondaparinux had no effect. Addition of fondaparinux to bivalirudin or low-dose heparin attenuated catheter-induced clotting more than either agent alone. In a rabbit model of catheter thrombosis, a 70 anti-Xa U/kg intravenous bolus of heparin or enoxaparin prolonged the time to catheter occlusion by 4.6- and 2.5-fold, respectively, compared with saline, whereas the same dose of fondaparinux had no effect. Although 15 anti-Xa U/kg heparin had no effect on its own, when given in conjunction with 70 anti-Xa U/kg fondaparinux, the time to catheter occlusion was prolonged 2.9-fold. These findings indicate that (1) catheters are prothrombotic because they trigger fXII activation, and (2) fondaparinux does not prevent catheter-induced clotting unless supplemented with low-dose heparin or bivalirudin.

Topics: Animals; Anticoagulants; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Catheters; Disease Models, Animal; Drug Synergism; Enoxaparin; Factor XII; Fondaparinux; Heparin; Humans; Male; Polysaccharides; Rabbits; Thrombosis

Edoxaban is an oral, direct factor Xa (FXa) inhibitor under late-phase clinical development. This study compared the antithrombotic efficacy of edoxaban with that of an indirect FXa inhibitor, fondaparinux, in in vivo venous and arterial thrombosis models and in ex vivo perfusion chamber thrombosis model under low and high shear rates in rats. Venous and arterial thrombi were induced by platinum wire insertion into the inferior vena cava and by application of FeCl₃ to the carotid artery, respectively. The perfusion chamber thrombus was formed by blood perfusion into a collagen-coated capillary at 150 s⁻¹ (low shear rate) and 1,600 s⁻¹ (high shear rate). Effective doses of edoxaban that reduced thrombus formation by 50% (ED₅₀) in venous and arterial thrombosis models were 0.076 and 0.093 mg/kg/h, respectively. In contrast, ED₅₀ of fondaparinux in the arterial thrombosis model (>10 mg/kg/h) was markedly higher compared to ED₅₀ in the venous thrombosis model (0.021 mg/kg/h). In the perfusion chamber thrombosis model, the ratio of ED₅₀ under high shear rate (1.13 mg/kg/h) to that under low shear rate (0.63 mg/kg/h) for edoxaban was 1.9, whereas that for fondaparinux was more than 66. While the efficacy of fondaparinux markedly decreased in arterial thrombosis and in a high-shear state, edoxaban exerted consistent antithrombotic effects regardless of flow conditions. These results suggest that shear rate is a key factor in different antithrombotic effects between edoxaban and fondaparinux.

Topics: Animals; Anticoagulants; Antithrombins; Blood Flow Velocity; Carotid Arteries; Disease Models, Animal; Factor Xa Inhibitors; Fondaparinux; Humans; Male; Polysaccharides; Pyridines; Rats; Rats, Wistar; Thiazoles; Thrombosis; Vena Cava, Inferior

Fondaparinux is a synthetic pentasaccharide with powerful anticoagulant properties, which may also reduce ischemia-reperfusion (I/R) injury in vivo. However, the relative contributions of the anticoagulant and anti-inflammatory activities of fondaparinux to the observed protection are unknown. To address this issue, a crystalloid-perfused heart model was used to assess potential effects of fondaparinux on IR-induced heart injury in the absence of blood. Fondaparinux protects the ischemic myocardium independently of its haemostasis effects. Fondaparinux improved post ischemic myocardial contractile performance and tissue damage. These beneficial effects of fondaparinux may be related to the observed reduction in IR-induced oxidative stress and endothelial activation. In addition, fondaparinux altered NADPH oxidase activity and phosphorylated extracellular signal-regulated kinase (ERK) 1/2, suggesting activation of survival signaling pathways. The present study provides novel information by demonstrating that fondaparinux can attenuate inflammatory responses and oxidative stress in connection with IR heart injury. These findings could represent a potential therapeutic strategy for the prevention of myocardial dysfunction.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Cells, Cultured; Coronary Vessels; Disease Models, Animal; Endothelial Cells; Fondaparinux; Hydrogen Peroxide; Leukocyte Rolling; Male; Microvessels; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Myoblasts, Cardiac; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion Injury; NADPH Oxidases; Oxidation-Reduction; Oxidative Stress; Perfusion; Phosphorylation; Polysaccharides; Rats; Rats, Sprague-Dawley; Ventricular Function, Left; Ventricular Pressure

Previous studies have demonstrated that dysregulated coagulation and fibrinolysis contribute to the pathogenesis of asthma.. The role of procoagulant factor X in a murine model of ovalbumin (OVA)-induced asthma was investigated.. Biochemical, cellular, and physiologic in vivo and in vitro approaches were used to determine effects of factor X on the asthmatic response in mice.. Factor X transcript levels and factor Xa activity were increased in lungs of asthmatic mice challenged with OVA, compared with controls treated with phosphate-buffered saline. Factor X was highly expressed in bronchoalveolar lavage fluid macrophages from asthmatic mice. Treatment of mice with the factor Xa inhibitor fondaparinux during the last 4 wk of OVA challenge resulted in the attenuation of airway hyperresponsiveness but did not alter infiltration of inflammatory cells into the lung. There was a significant decrease in the thickness of the mucosal layer and in lung collagen deposition in fondaparinux-treated mice. In vitro investigations using human mucus-producing NCI-H292 cells indicated that exogenous factor Xa enhanced mucin production in a dose-dependent manner. Levels of amphiregulin, a protein that induces mucin production, were also increased in cells stimulated by factor Xa.. The results of this study introduce a novel participant in the asthmatic response and indicate that factor Xa functions in airway remodeling in asthma by stimulating mucin production, through regulation of amphiregulin expression and collagen deposition.

Topics: Amphiregulin; Animals; Asthma; Bronchoalveolar Lavage Fluid; Cells, Cultured; Collagen; Disease Models, Animal; EGF Family of Proteins; Factor Xa; Factor Xa Inhibitors; Fondaparinux; Glycoproteins; Goblet Cells; Humans; Hydroxyproline; Hyperplasia; Intercellular Signaling Peptides and Proteins; Lung; Male; Mice; Mice, Inbred Strains; Mucins; Ovalbumin; Polysaccharides; Receptor, PAR-1; Receptor, PAR-2; Respiration; RNA, Messenger; Thrombin

Current anticoagulant therapies for the prevention and treatment of thromboembolic disorders have many drawbacks: vitamin K antagonists interact with food and drugs and require frequent laboratory monitoring, and heparins require parenteral administration. Oral rivaroxaban (BAY 597939) is a new, highly selective and potent direct factor-Xa (FXa) inhibitor with a predictable pharmacodynamic and pharmacokinetic profile and could therefore be an attractive antithrombotic drug. It was the objective of this study to investigate the antithrombotic efficacy of oral rivaroxaban in two rabbit models of experimental venous thrombosis. In the venous stasis (prevention) model, animals were randomized to receive oral rivaroxaban 0.3, 1.0, 3.0 or 10.0 mg/kg or vehicle control. Thrombosis was induced by jugular vein stasis and injection of thromboplastin into the ear vein. In the venous thrombosis (treatment) model, intravenous (1.0 and 3.0 mg/kg) and oral (3.0 mg/kg) rivaroxaban was compared with intravenous nadroparin (40 U bolus and 20 U/h), fondaparinux (42 microg/kg) and vehicle control. Thrombus growth was assessed by measuring the accretion of radiolabelled fibrinogen into preformed clots in the jugular veins. Bleeding was assessed using an ear bleeding model. In the prevention model, rivaroxaban reduced thrombus formation dose-dependently (calculated ED(50) 1.3 mg/kg). In the treatment model, oral rivaroxaban (3.0 mg/kg) reduced thrombus growth to a similar extent to intravenous rivaroxaban (1.0 mg/kg), nadroparin and fondaparinux. Oral rivaroxaban did not prolong bleeding time. In conclusion, the orally available selective, direct FXa inhibitor rivaroxaban is effective in the prevention and treatment of venous thrombosis in two well-established models of experimental thrombosis.

Topics: Administration, Oral; Animals; Anticoagulants; Blood Coagulation Tests; Disease Models, Animal; Dose-Response Relationship, Drug; Factor Xa Inhibitors; Fibrinolytic Agents; Fondaparinux; Hemorrhage; Humans; Infusions, Intravenous; Injections, Intravenous; Jugular Veins; Ligation; Morpholines; Nadroparin; Polysaccharides; Rabbits; Random Allocation; Rivaroxaban; Thiophenes; Thromboplastin; Venous Thrombosis

The purpose of this study was to evaluate the effects of fondaparinux, a selective antithrombin III agonist, in comparison to the low-molecular-weight heparin enoxaparin in the survival of a congested skin flap.. Eighteen axial-pattern auricular flaps were performed on rabbits using a well-described congested flap model. Animals were randomized into 2 treatment groups, enoxaparin (n = 6) and fondaparinux (n = 6), and a control group (n = 6) that received no treatment. Skin flap survival area was measured postoperatively at 7 and 14 days.. The groups that received fondaparinux and enoxaparin had similar mean flap survival areas and were not statistically different. However, both treatment groups significantly increased flap survival compared with controls (P < 0.014).. Fondaparinux, like enoxaparin, significantly improves survival of congested flaps in rabbits. Its use instead of enoxaparin may be warranted, given that it eliminates the risk of heparin-induced thrombocytopenia. Further study in humans is warranted.

Topics: Animals; Anticoagulants; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Enoxaparin; Fondaparinux; Graft Rejection; Graft Survival; Injections, Subcutaneous; Polysaccharides; Rabbits; Random Allocation; Reference Values; Sensitivity and Specificity; Skin Transplantation; Surgical Flaps

Upregulation of the activated Factor VII (FVIIa)/Tissue Factor complex, downregulation of natural anticoagulation pathways, and inhibition of fibrinolysis, are major contributors to coagulopathies associated with acute inflammation. Provision of FVIIa, and consequent downstream coagulation-related proteases, also stimulates further inflammatory changes, which can result in disseminated intravascular coagulation. Thus, the potential protective effects in vivo of a genetic-based reduction in FVII levels have been investigated in a murine model of acute inflammation, namely lipopolysaccharide (LPS)-induced lethal endotoxaemia. Mice with a total FVII deficiency do not survive the neonatal period. Therefore mice expressing low levels of FVII (FVII(tTA/tTA)), producing sufficient amounts of FVII for survival (approximately 5% of wild-type (WT) FVII), were employed to investigate in vivo pathways involved in the crosstalk between coagulation, inflammation, and survival, consequent to administration of a lethal dose of LPS. The FVII(tTA/tTA) mice presented with reduced mortality, coagulation, and inflammatory responses in comparison with similarly treated WT mice after administration of LPS. The attenuated inflammatory responses in FVII(tTA/tTA) mice were associated with downregulation of Egr-1 signalling. Administration, in vivo, of specific inhibitors of FXa and thrombin demonstrated that the inflammatory responses were unaltered in WT mice, but further reduced in FVII(tTA/tTA) mice. Therefore, a FVII deficiency enhances survival from lethal endotoxaemia both through attenuation of inflammatory responses that result directly from reduced FVIIa levels, and, indirectly, from downregulation of coagulation proteases downstream of the FVII-dependent cascade.

Topics: Ancrod; Animals; Anticoagulants; Antithrombin III; Biomarkers; Blood Coagulation; Disease Models, Animal; Down-Regulation; Early Growth Response Protein 1; Endotoxemia; Factor VII Deficiency; Factor Xa; Fibrinogen; Fondaparinux; Hirudins; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Neutrophils; Peptide Hydrolases; Polysaccharides; Recombinant Proteins; Signal Transduction; Thrombin

Fondaparinux is a synthetic pentasaccharide that selectively inhibits factor Xa (FXa) in an antithrombin-dependent fashion. This newly developed anticoagulant is used in the prevention and treatment of venous thromboembolism. Recently, we showed that fondaparinux reduces inflammation and protects the kidney from ischemia-reperfusion (I/R) injury. However, the relative contributions of the anticoagulant and anti-inflammatory activities of fondaparinux to the observed protection is unknown. To address this, we chemically modified fondaparinux to abolish its affinity for antithrombin and analyzed the effect of this non-anticoagulant (NAC)-pentasaccharide on binding of U937 cells to P-selectin in vitro and on inflammation in a murine model of kidney I/R injury. NAC-pentasaccharide was as effective as fondaparinux at inhibiting the binding of U937 cells to P-selectin. In addition, NAC-pentasaccharide significantly reduced IL-6 and MIP-2 expression and injury in the kidney I/R model. These findings indicate that the anti-inflammatory activity of fondaparinux can be dissociated from its anticoagulant activity and that NAC-pentasaccharide is protective in kidney I/R injury.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Anticoagulants; Blood Coagulation; Cell Adhesion; Chemokine CCL2; Chemokine CXCL2; Chemokines; Creatinine; Disease Models, Animal; Factor Xa Inhibitors; Fondaparinux; Humans; Inflammation; Interleukin-6; Kidney; Kidney Tubules; Macrophages; Mice; Neutrophil Infiltration; Oligosaccharides; P-Selectin; Partial Thromboplastin Time; Polysaccharides; Reperfusion Injury; U937 Cells

The activity of SanOrg123781A, a new synthetic antithrombotic drug inhibiting both factor Xa and thrombin through antithrombin (AT), was compared to that of unfractionated heparin (UFH) and of the synthetic pentasaccharide (fondaparinux, SP) in an ex vivo arterial thrombosis model in the pig. Six groups of four pigs were administered intravenously with SanOrg123781A (1, 3, 10 and 30 nmol kg(-1)), UFH (30 nmol kg(-1)) or SP (30 nmol kg(-1)). In this arterial model in which platelet thrombus was formed on a thrombogenic surface under a constant high shear rate, UFH and SP had moderate antithrombotic effects while SanOrg123781A exhibited a strong, dose-dependent inhibitory activity on platelet adhesion and platelet thrombus formation. In contrast to UFH, SanOrg123781A did not modify the activated partial thromboplastin time (aPTT) even at 30 nmol kg(-1), but strongly inhibited thrombin generation. At the same dose, despite a lower antithrombotic activity than SanOrg123781A, UFH significantly affected all the coagulation parameters. Taken together, these results show that SanOrg123781A, due to its potent and selective antifactor Xa and antifactor IIa activities is a promising new antithrombotic agent even in arterial setting.

Topics: Animals; Blood Platelets; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Factor Xa Inhibitors; Fondaparinux; Heparin; Partial Thromboplastin Time; Polysaccharides; Prothrombin; Swine; Thrombosis

On a previous model using Wessler's principle in the rat, we have demonstrated that a partial ligature of the inferior vena cava leading to a 40% increase in up-stream venous pressure was thrombogenic only in association with the infusion of low dose of thromboplastin (90 microg/kg). In these thrombogenic conditions, the infusion of pentasaccharide (Arixtra, fondaparinux) should lead to a strong inhibition of thrombus formation. Therefore, we performed on five groups of 10 rats: stasis alone (group S) with a 40% increase in up-stream venous pressure; stasis and thromboplastin (group ST90); and stasis, thromboplastin and pentasaccharide (groups SPT50, SPT100 and SPT250) at three different dosages (50, 100 and 250 microg/kg). The efficacy of pentasaccharide was measured according to the variations in up-stream venous pressure, thrombus weight and thrombin-antithrombin complexes levels. Only 250 microl/kg pentasaccharide significantly reduced the thrombus weight in comparison with group ST90 (5 mg versus 23.8 mg, P = 0.01) but it was not sufficient to induce a return to the basic state (5 mg versus 0.2 mg in group S, P = 0.049). Thrombin-antithrombin complex levels measured at the end of the experiment were significantly reduced in comparison with group ST90 (16.7 versus 57.8 mg, P = 0.01) and were not statistically different from group S (16.1 versus 16.6 mg, P = 0.65). In conclusion, in a very borderline model toward thrombogenesis, pentasaccharide was able to reduce thrombus weight and abolished biological hypercoagulability.

Topics: Animals; Antithrombin III; Blood Pressure; Disease Models, Animal; Dose-Response Relationship, Drug; Fondaparinux; Hemostasis; Male; Peptide Hydrolases; Polysaccharides; Rats; Rats, Sprague-Dawley; Thrombophilia; Thromboplastin; Thrombosis; Treatment Outcome