Disseminated Intravascular Coagulation In Rats Research Articles

Relationship between endothelin and the pathophysiology of tissue factor-induced and lipopolysaccharide-induced disseminated intravascular coagulation in rats: a study examining the effect of an endothelin receptor antagonist.

We investigated the relationship between endothelin, a potent vasoconstrictor peptide, and the pathophysiology of disseminated intravascular coagulation (DIC), using two models of DIC. Experimental DIC was induced by sustained infusion of 50 mg/kg lipopolysaccharide (LPS), or 3.75 U/kg thromboplastin, for 4 h via the rat tail vein. The effect of administration of a non-selective endothelin receptor antagonist (TAK-044) (2, 10, or 50 mg/kg, from -0.5 to 4 h) on thromboplastin-induced DIC was not significant. However, LPS-induced elevation of alanine aminotransferase, creatinine and glomerular fibrin deposition was significantly suppressed by co-administration of TAK-044 in a dose-dependent manner, although no effect of TAK-044 was observed on the platelet count, fibrinogen concentration or the level of thrombin-antithrombin complex. Moreover, plasma levels of D-dimer, which reflect the grade of fibrinolysis of cross-linked fibrin, were significantly increased by co-administration of each dose of TAK-044 in the LPS-induced DIC model in rats. Our results suggest that vasoconstriction, as well as depressed fibrinolysis, contribute to severe organ dysfunction in LPS-induced, but not thromboplastin-induced, DIC, and that endothelin plays a role in the development of organ injury in LPS-induced DIC in rats.

Effect of Urinary Protein C Inhibitor on Lipopolysaccharide-induced Disseminated Intravascular Coagulation in Rats

The effect of urinary protein C inhibitor (uPCI) on disseminated intravascular coagulation (DIC) was investigated using an experimental DIC in rats. uPCI (0.5 and 1.0 mg/kg) was continuously administrated into the left femoral vein of the rats with lipopolysaccharide (50 mg/kg)-induced DIC. In all doses, uPCI significantly prevented the drastic changes in the parameters such as fibrinogen concentration, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrin/fibrinogen degradation products (FDP) level, aspartate amino-transferase (AST) level and alanine aminotransferase (ALT) level. Furthermore, uPCI significantly inhibited the increase in the levels of plasma kallikrein and thrombin which act not only as the procoagulant proteases but also as the chemotactic factors to neutrophils and monocytes. These results show that uPCI may prevent hypercoagulation, the induction of secondary fibrinolysis and organ failure in the DIC model. Therefore, uPCI may be a useful agent for the clinical treatment of DIC.

Effects of a highly selective synthetic inhibitor of plasma kallikrein on disseminated intravascular coagulation in rats

We found a new, highly selective plasma kallikrein inhibitor, trans-4-aminomethyl-cyclohexanecarbonylphenylalanine 4-carboxymethylanilide hydrochloride, called PKSI-527 in our laboratories. This study was conducted to evaluate PKSI-527, on thromboplastin (TP)- and endotoxin (LPS)-induced disseminated intravascular coagulation (DIC) in rats. PKSI-527 was infused intravenously at 0.1 mg/kg/min for 250 min. Three of the parameters of the coagulation and fibrinolysis system, fibrinogen level, platelet counts and fibrin(ogen) degradation products (FDP) level were assayed. PKSI-527 prevented the change in the coagulation and fibrinolysis system in LPS-induced DIC, however it was not clearly effective in TP-induced DIC. The parameters of organ failure, such as serum glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), creatine phosphokinase (CPK), lactate, blood urea nitrogen and β-glucuronidase, were assayed. Although the changes in the fibrinogen level, platelet counts and FDP level were almost the same in both models, the parameters of organ failure apparently increased in LPS-induced DIC more so than in TP-induced DIC. PKSI-527 significantly suppressed the increases in GOT and GPT in LPS-induced DIC. These results indicate that plasma kallikrein may play a significant role in LPS-induced DIC. Therefore, PKSI-527, as a synthetic plasma kallikrein inhibitor may be a valuable tool to explore the mechanism of DIC and the accompanying organ failure.

Effects of Recombinant Human Soluble Thrombomodulin (rhs-TM) on a Rat Model of Disseminated Intravascular Coagulation with Decreased Levels of Plasma Antithrombin III

We reported that recombinant human soluble thrombomodulin (rhs-TM) is effective for disseminated intravascular coagulation (DIC) in vivo, in mice and rats. In the present work, we investigated the effects of decreased plasma antithrombin III (ATIII) levels on anticoagulant effects of rhs-TM, as compared to findings with heparin, of which effect is lowered by the decreased plasma ATIII levels in patients with DIC. Rat plasma ATIII levels decreased when we mixed plasma with anti-rat ATIII antibody and the potential of heparin to prolong APTT or PT was markedly diminished. The potential of rhs-TM to prolong APTT and PT was not affected. In rats injected with anti-rat ATIII antibody, plasma ATIII levels decreased immediately. When the rats were infused with tissue factor (TF), DIC was induced. At doses of rhs-TM and heparin which were equally effective at inhibiting the decrease in platelet count and fibrinogen level in control rats treated with TF, only rhs-TM remained effective in preventing DIC in rats with reduced ATIII levels. Heparin was not effective when administered to these rats with reduced ATIII levels. Therefore, rhs-TM effectively inhibits coagulation independent of ATIII levels, in contrast to heparin, which depends on the ATIII level.

The Glycosaminoglycan of Recombinant Human Soluble Thrombomodulin Affects Antithrombotic Activity in a Rat Model of Tissue Factor-Induced Disseminated Intravascular Coagulation

Previous studies on recombinant human soluble thrombomodulin (rsTM) from Chinese hamster ovary cells revealed that rsTM was expressed as two proteins that differed functionally in vitro due to the presence (rsTM beta) or absence (rsTM alpha) of chondroitin-4-sulfate. The current study evaluates the in vivo behavior of rsTM in rats and in a rat model of tissue factor-induced disseminated intravascular coagulation (DIC). rsTM beta was more potent than rsTM alpha for prolongation of the activated partial thromboplastin time (APTT) and their in vivo half-lives determined by ELISA were 20 min for rsTM beta and 5.0 h for rsTM alpha. Injection of a tissue factor suspension (5 mg/kg) resulted in DIC as judged by decreased platelet counts and fibrinogen concentrations, prolonged APTT, and increased fibrin and fibrinogen degradation products (FDP) levels. A bolus injection of either rsTM (0.2 mg/kg) 1 min before induction of DIC essentially neutralized effects on platelets, fibrinogen, and FDP levels, and had only a moderate effect on APTT prolongation. The dose of anticoagulant to inhibit the drop in platelet counts by 50% (ED50) was 0.2 mg/kg rsTM alpha, 0.07 mg/kg rsTM beta, and 7 U/kg heparin. The effect of increasing concentrations of rsTM and heparin on bleeding times were compared in experiments involving incision of the rat tail. Doubling of the bleeding times occurred at 5 mg/kg rsTM alpha, 3 mg/kg rsTM beta or 90 U/kg heparin. These values represent a 25-fold increase over the ED50 for rsTM alpha, 43-fold for rsTM beta and 13-fold for heparin.(ABSTRACT TRUNCATED AT 250 WORDS)

低分子量Ｈｅｐａｒｉｎ（ＦＲ‐８６０）の実験的播種性血管内凝固症候群に対する効果

Effects of low molecular weight heparin (FR-860) on experimental disseminated intravascular coagulation (DIC) models in rats were compared with those of conventional unfractionated heparin (UF-heparin) and other anticoagulants. In the endotoxin-induced DIC model, FR-860 (12.5-200 U/kg/hr) and UF-heparin (25-200 U/kg/hr) inhibited dose-dependently the decreases in platelet counts, fibrinogen, antithrombin III activity and alpha 2-plasmin inhibitor activity, and they also inhibited the increases in fibrin de-products and thrombus formation in the glomerular capillary bed. Neither gabexate mesilate (FOY, 10 mg/kg/hr) nor nafamostat mesilate (FUT, 0.1 mg/kg/hr) improved endotoxin-induced DIC. FR-860 showed comparable potency to UF-heparin in plasma anti-factor Xa (F.Xa) activity. However, FR-860 was weaker than UF-heparin in prolongation of activated partial thromboplastin time. In the thrombin-induced DIC model, both FR-860 and UF-heparin significantly improved, as seen in the endotoxin-induced DIC model, the changes in coagulation and fibrinolytic parameters and suppressed the production of pulmonary thrombus. On the other hand, both FOY and FUT showed significant but weak improvement in this model. In addition, FR-860 inhibited the enhancement of fibrinolysis and the production of pulmonary thrombus in the lactic acid-induced DIC model. These results suggest that the efficacy of FR-860 on DIC in rats is comparable to that of UF-heparin and that the efficacy can be attributed to its anti-F.Xa activity. FR-860 can be expected to be a useful therapeutic drug for DIC.

Protective effects of ONO-3307, a new synthetic protease inhibitor against experimental disseminated intravascular coagulation in rats

The effects of ONO-3307 (4-sulfamoylphenyl 4-guanidinobenzoate methanesulfonate), a new synthetic protease inhibitor, on endotoxin-induced experimental disseminated intravascular coagulation (DIC) were studied in rats. Experimental DIC was induced by a 4-h sustained infusion of endotoxin at a dose of 100mg/kg. The rats were infused continuously with ONO-3307 at a dose of 1, 10 or 100 μg/kg/h into a femoral vein for 4 h. Simultaneously with the agent infusion, endotoxin (100mg/kg/ 4h) was administered into the contralateral femoral vein. A protective effect against DIC was noted in the rats treated with 10 or 100 μg/kg/h of ONO-3307 in the following parameters: fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count and the number of renal glomeruli with fibrin thrombi. Therefore, ONO-3307 inhibited the aggravation of endotoxin-induced experimental DIC in rats.

Role of activated platelets in endotoxin-induced DIC in rats

To clarify whether activated platelets play an important role in the occurrence and exacerbation of disseminated intravascular coagulation (DIC), we investigated the effects of 4 anti-platelet drugs, a PGI 2 analog(CS-570), a thromboxane synthetase inhibitor (dazoxiben), a thromboxane receptor antagonist (BM-13177), and ticlopidine, in an experimental DIC model in rats. Experimental DIC was induced by a continuous infusion of lipopolysaccharide (LPS derived from E. coli, 055 B5, 25 mg/kg/hr) for 4 hrs. In the time-course determination of the coagulation parameters and prostanoids, an abrupt increase in TxB 2 (a stable metabolite of TxA 2) and 6-keto-PGF 1α (a stable metabolite of PGI 2) was followed by a decrease in platelet count, a prolongation of blood coagulation time, and an increase in fibrinogen/fibrin degradation products (FDP). Four hours after the start of LPS infusion, the rats were considered to be in the state of DIC. The effects of the anti-platelet drugs were investigated 4 hrs after the start of LPS infusion. CS-570 and ticlopidine ameliorated DIC in a dose-dependent manner. CS-570 ( 10 μg/kg/min ) improved DIC in the platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen ( Fbg ), and FDP, without affecting TxB 2 and 6-keto-PGF 1α formation. Ticlopidine (200 mg/kg, i.p.) prevented the excervation of DIC in such item parameters as platelet count, APTT, and FDP. Both dazoxiben and BM-13177 (30 mg/kg, i.p.) ameliorated DIC in following parameters as platelet count, APTT and FDP. Dazoxiben, but not BM-13177, significantly inhibited the increase in TxB 2 concentration at 4 hr. These observations suggest that drugs which inhibit platelet activation by a TxA 2-dependent route are effective in improving DIC induced by LPS, and that drugs which inhibit multiple platelet-activating routes improve DIC in more item parameters than drugs which inhibit only the TxA 2-dependent activating route. Consequently, it is concluded that activated platelets might play an important role in the occurrence and exacerbation of DIC induced by LPS, and that one of the roles of TxA 2 in DIC is to activate platelets.

Effect of urinastatin on disseminated intravascular coagulation

Effect of urinary enzyme inhibitor urinastatin (MTI) on disseminated intravascular coagulation (DIC) was investigated. The prolongation of PTT and increase in FDP in endotoxin-induced DIC in rats were restored by the intravenous infusion of MTI. The reduction in platelet counts, decrease in fibrinogen level and prolongation of PT were partially suppressed by the drug. Furthermore, in vitro addition of MTI prevented the decrease in r and k values and increase in ma and m epsilon values in the thromboelastogram of whole blood in endotoxin-induced DIC in rabbits. It is suggested that MTI might prevent DIC in vivo and in vitro through the inhibition of Factor XII activity and through the prevention of thromboplastin release caused by endotoxin.

Preventive effect of 2-halogen-substituted derivatives of cyclic adenosine 3',5'-monophosphate on experimental disseminated intravascular coagulation.

Cyclic adensine 3', 5'-monophosphate (cAMP) derivatives were tested for inhibitory effect on the development of experimental disseminated intravascular coagulation (DIC). Two compounds, 2-Cl-cAMP and 2-Br-cAMP, which inhibited the platelet aggregation induced by collagen in vitro, had a strong inhibitory effect on the development of experimental DIC in rats in vivo as judged by five diagnostic laboratory tests, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrin and fibrinogen degradation products (FDP), fibrinogen and platelet count. The effect of these derivatives was preventive rather than therapeutic, and the inhibition of rat platelet aggregation by these substances was marked when the stimulator was collagen or thrombin but less strong when it was calcium ionophore A23187 or adenosine 5'-diphosphate (ADP).

Effect of Panax notoginseng on experimental disseminated intravascular coagulation (DIC)

Anti-thrombic activities of 70% methanol extracts obtained from the roots of Panax notoginseng (BURK.) F.H. CHEN were investigated in the experimental model of disseminated intravascular coagulation (DIC). In coagulative system, the 70% methanol extracts at a dose of 200 mg/kg inhibited the decrease of blood platelets and fibrinogen and the formation of hemorrhagic necrosis of liver on endotoxin-induced DIC in rats. In order to clarify the mechanism for DIC, in vitro effects of the 70% methanol extracts and its various fractions on the coagulative system were examined with endotoxin-, collagen-, ADP- and arachidonic acid-induced blood platelet aggregation and conversion of fibrinogen to fibrin induced by thrombin. As a result, the 70% methanol extracts and its ethylacetate soluble portion were found to inhibit the conversion of fibrinogen to fibrin. However, the 70% methanol extracts had no inhibitory effect on blood platelet aggregation. In fibrinolytic system, effects of Panax notoginseng on fibrinolytic activity were examined in rats as determined by euglobulin lysis time and fibrin plate assay. As a result, the 70% methanol extracts at a dose of 200 mg/kg was found to reduce the euglobulin lysis time in rats. And also, the 70% methanol extracts and its n-BuOH soluble portion promoted urokinase action in a plasminogen-containing fibrin plate. On the basis of the in vivo and in vitro experimental results, it is suggested that Panax notoginseng can be considered as having anti-DIC activity. And, one of its mechanism on DIC may be due to the inhibitory effect on conversion of fibrinogen to fibrin and the promotional effect on urokinase action for plasminogen.

The effects of defibrinogenation with batroxobin on endotoxin-induced disseminated intravascular coagulation in rats

Experimental disseminated intravascular coagulation (DIC) can be induced by a 4-hr sustained infusion of endotoxin at a dose of 100 mg/kg in rats. This experimental model of DIC in rats was used to study the effects of defibrinogenation with batroxobin against DIC. One hour before the infusion of endotoxin, 200 batroxobin unit (BU)/kg of batroxobin was injected intraperitoneally. Immediately after the injection, fibrinogen level markedly decreased and fibrinogen and fibrin degradation products increased. Prothrombin time and partial thromboplastin time were also prolonged. Blood counts, platelet counts and hematocrit level only showed a slight decrease after the injection. The preventive effect against DIC was noted by the partial inhibition of the fall in the platelet counts and lessened number of renal glomeruli with fibrin thrombi, in the rats treated with 200 BU/kg of batroxobin 1 hr before the infusion of endotoxin (100 mg/kg/4hr). From these results, it was shown that fibrinogen metabolism plays an important role in the DIC state.

Effect of dipyridamole on experimental disseminated intravascular coagulation in rats

Experimental disseminated intravascular coagulation (DIC) can be induced by 4-h sustained infusion of endotoxin in a dose of 100 mg/kg in rats. The experimental model of DIC in rats was used to study the preventive effect of dipyridamole against DIC. Before the infusion of endotoxin, 0.5, 5.0 or 50.0 mg/kg of dipyridamole was injected intraperitoneally. The preventive effect against DIC was noted in all the parameters, such as fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count, and the number of renal glomeruli with fibrin thrombi, in rats treated with 5.0 or 50.0 mg/kg of dipyridamole. From these results, it was shown that dipyridamole inhibited the aggravation of endotoxin-induced experimental DIC in rats.

Protective effect of gabexate mesilate against experimental disseminated intravascular coagulation in rats.

Experimental disseminated intravascular coagulation (DIC) can be induced by 4 h sustained infusion of endotoxin at a dose of 100 mg/kg in rats. The experimental model of DIC in rats was used to study the preventive effect of gabexate mesilate (GM) against DIC. Before the infusion of endotoxin, 10(-6), 10(-3), 1, 10, 50 or 100 mg/kg of GM was injected intraperitoneally. The preventive effects against DIC were noted in all the parameters, such as fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count, and the number of renal glomeruli with fibrin thrombi, in rats treated with 1, 10 or 50 mg/kg of GM. From these results it was shown that GM inhibited the aggravation of endotoxin-induced experimental DIC in rats.

薬用人参の薬理学的研究(第1報)実験的Disseminated Intravascular Coagulationに対する紅参の作用 その1

The antithrombic activities of 70% methanol extract (I) obtained from Korean red ginseng (root of Panax ginseng C.A. MEYER) were evaluated in the models of experimental disseminated intravascular coagulation (DIC) induced by endotoxin or thrombin in rats, and in the in vitro models of blood platelet aggregation, agglutination of fibrinogen and activation of fibrinolytic system. In the coagulative system, I prevented the exchanges of values of clinical examination (blood platelet, fibrinogen and prothrombin time) at a dose of 500 mg/kg in rats on DIC induced by endotoxin or thrombin. I also inhibited the formation of fibrin thrombi in the renal glomeruli on the thrombin-induced DIC in rats. In the fibrinolytic system, I was found to show fibrinolytic activity in rats as determined by the euglobulin lysis time (ELT) assay. In the in vitro experiments, incubation of I in the plasminogen-containing fibrin plate promoted activation of urokinase action.

Effect of Vitamin E on Endotoxin-Induced Disseminated Intravascular Coagulation in Rats

Experimental disseminated intravascular coagulation (DIC) can be induced by 4 hr sustained infusion of endotoxin in a dose of 100 mg/kg in rats. The experimental model of DIC in rats was used to study the preventive effect of vitamin E, alpha-tocopheryl acetate, against DIC. Before the infusion of endotoxin, 0.01, 0.1, 1.0 or 10.0 mg/kg/day of alpha-tocopheryl acetate was injected intraperitoneally for 4 successive days. The preventive effect against DIC was noted in all the parameters, such as fibrinogen and fibrin degradation products, fibrinogen level, prothrombin time, partial thromboplastin time, platelet count, and the number of renal glomeruli with fibrin thrombi, in rats treated with 1.0 or 10.0 mg/kg of alpha-tocopheryl acetate. From these results, it was shown that vitamin E, alpha-tocopheryl acetate, inhibited endotoxin-induced experimental DIC in rats.

Experimental model of disseminated intravascular coagulation induced by sustained infusion of endotoxin.

Experimental disseminated intravascular coagulation (DIC) was induced by sustained infusion of endotoxin into the femoral vein in rats. The severity of DIC was determined with reference to various parameters, such as fibrinogen and fibrin degradation products (FDP), prothrombin time (PT), partial thromboplastin time (PTT), platelet count, and number of renal glomeruli having fibrin thrombi. Experimental DIC could be induced by a 4-h sustained infusion of endotoxin in a dose of 100 mg/kg. The DIC induced in rats showed a close resemblance to human DIC as judged from such changes as an elevation in FDP, prolongation of PT and PTT, depression in fibrinogen and platelet count, and increase in glomeruli having fibrin thrombi. This experimental model has an advantage in that severity of DIC can be determined by measuring various parameters. It will be of use in the studies aimed at the establishment of a therapy for DIC as well as in the studies on DIC in rats.

The influence of drugs on disseminated intravascular coagulation (DIC) V. Effects of α-adrenoceptor blocking agents on thrombin-induced DIC in rats

The influence of various types of antiadrenergic agents ( α 1- and/or α 2-receptor blockers) on DIC induced by thrombin infusion in rats was studied. Changes in the DIC-sensitive parameters, microthrombosis in the lungs and kidneys and the decrease in oxygen consumption were prevented or inhibited by dibenamine and dihydroergotamine. Yohimbine was less effective in preventing DIC, it caused, however, an increase in microthrombosis in the lungs. The adrenergic effects in DIC are concluded to be mediated by stimulation of α 1-receptors.

The influence of drugs on disseminated intravascular coagulation (DIC) IV. Effects of the thrombin-like enzyme batroxobin on thrombin-induced DIC in rats

The influence of defibrinogenation with batroxobin on thrombin-induced disseminated intravascular coagulation (DIC) was studied in rats. Injection of low batroxobin doses caused defibrinogenation and secondary fibrinolysis without formation of microthrombi. High doses caused transient microthrombosis in the lungs, subsequent defibrinogenation and formation of fibrin degradation products (FDP). The response of platelets to aggregation-inducing agents was inhibited. In animals pretreated with batroxobin the fall in platelet counts and the increase in plasma haemoglobin caused by thrombin infusion were diminished. Formation of 125I-fibrin thrombi in the lungs, kidneys, spleen and adrenals was prevented, the pulmonary uptake of 51Cr-labelled platelets was reduced.

The influence of drugs on disseminated intravascular coagulation (DIC) I. Effects of antifibrinolytics and fibrinolytics on thrombin-induced DIC in rats

The effects of the antifibrinolytic PAMBA and of a protease from Aspergillus ochraceus, ocrase, on consumption coagulopathy and disseminated intravascular coagulation (DIC) induced by thrombin infusion are studied in rats. In the organs investigated (lungs, liver, kidneys, suprarenals), application of PAMBA causes a significant increase in DIC and a decrease in oxygen consumption, whereas hematological changes (decrease in fibrinogen level and platelet count, appearance of fibrin monomers and of free plasma hemoglobin) are not influenced. Application of ocrase causes a rapid lysis of microthrombi. A repatency of the microvasculature is reached, whereby the impaired oxygen consumption is gradually normalized and tissue lesions appear more infrequently.