Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of ONO-3307 (4-sulfamoyl phenyl-4-guanidinobenzoate methanesulfonate), a new protease inhibitor, was studied on various proteases in vitro and in an experimental thrombosis model in vivo. ONO-3307 competitively inhibited trypsin, thrombin, plasma kallikrein, plasmin, pancreatic kallikrein and chymotrypsin; and their Ki values were 0.048 microM, 0.18 microM, 0.29 microM, 0.31 microM, 3.6 microM and 47 microM, respectively. In addition, ONO-3307 inhibited both elastase release from N-formyl-Met-Leu-Phe (fMLP)-stimulated leukocytes and tissue thromboplastin release from endotoxin-stimulated leukocytes. To examine the effects of ONO-3307 on disseminated intravascular coagulation (DIC), we developed an experimental thrombosis model. ONO-3307 (10 mg/kg/hr) completely inhibited the deposition of radioactive fibrin in kidney and lung. Gabexate mesilate (50 mg/kg/hr) was also effective in this model, but the effect of nafamostat mesilate was unclear. These results indicate that ONO-3307 exhibits a wide range of inhibitory effects on various proteases, and ONO-3307 may be useful for the treatment of protease-mediated diseases such as thrombosis and DIC.
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PMID:Inhibitory effects of ONO-3307 on various proteases and tissue thromboplastin in vitro and on experimental thrombosis in vivo. 251 29

Some properties of a monoclonal antibody generated against the fibrinogen component of a factor VIII preparation were investigated. The antibody bound with equal affinity in solid phase radioimmunoassays to fibrinogens isolated from both normal patients and patients with von Willebrand disease. It reacted in a sensitive immunoassay of plasma fibrinogen. The specificity of the antibody was confined to the parent molecule with no significant inhibition of fibrinogen binding by the fibrinogen degradation products (FDPs) X, Y, D, or E. The antibody had no significant effect on the activated partial thromboplastin time and prothrombin time of normal plasma. However, it prolonged the thrombin time as determined by the Clauss chronometric fibrinogen method. During fibrinogen lysis by plasmin immunoreactivity of fibrinogen to the antibody was lost at the same rate as the clottable fibrinogen content determined by the Clauss assay. The lack of reactivity of the antibody with FDPs makes it a suitable reagent for investigating plasmin activity as well as studying fibrinogen and fibrin. These findings suggest that the epitope of the antibody lies within the polar protruberance of the carboxy terminal end of the A alpha chain of fibrinogen and is destroyed by plasmin cleavage.
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PMID:Some studies with a monoclonal antibody directed against human fibrinogen. 257 30

Fibrinolytic and fibrinase properties of the most of human organs and tissues have been studied. It has been established that fibrinolytic activity of the tissues highly varied. Fibrinolytic agents of the tissues are rather unstable to dilution, in contrast to thromboplastin, that is stable to dilutions as 1:10000 and 1:100000 and higher. All the tissues contain both activators and inhibitors of fibrinolysis. In some of them inhibitors prevail, that proves their antifibrinolytic properties. Tissue fibrinase decreasing fibrinolysis effectiveness, is detected almost in all tissues. The experiments with intravenous injection of extracts from different tissues have demonstrated that regardless of their fibrinolytic activity, the course of hemostasis impairment is of the same type: at the moment of the extract injection fibrinolysis is sharply inhibited, and then intravasal blood coagulation develops under the influence of strong tissue thromboplastin; the phase of hypercoagulemia is changed by that of hypocoagulemia attended by a secondary increase of fibrinolysis. The author believes that when "juices" of different tissues enter the blood flow the impairment of blood coagulation, by the mechanism of thrombohemorrhage syndrome (THS) takes place, and fibrinolysis is secondary-activated and represents a reaction of the second phase of THS.
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PMID:[Fibrinolytic and fibrin-stabilizing properties of human tissues]. 280 65

The inhibiting action in vitro of urinastatin on blood coagulation was studied for the purpose of therapeutic application against thrombotic disorders, and the following results were obtained: 1) Partial thromboplastin time of normal human plasma was prolonged dose-dependently by the addition of urinastatin to the reaction mixture, but prothrombin time was little inhibited by the addition of urinastatin. Thrombin time was also prolonged with urinastatin dose-dependently. 2) Using chromogenic synthetic peptide substrates, the amydolytic activities of XIIa, plasma kallikrein and Xa activated with RVV were inhibited by the addition of urinastatin to the reaction mixtures. 3) Activated partial thromboplastin time of normal plasma was prolonged by the addition of urinastatin or heparin, and simultaneous application of both urinastatin and heparin to the reaction mixture resulted in an additional inhibitory effect on APTT. Therefore, it was assumed that the different molecular structures of the clotting factors were concerned with the inhibitory actions of urinastatin and antithrombin III. Furthermore, urinastatin was indicated to have an important role in antithrombotic remedy, since it has no inhibitory action against protein C. 4) In the comparison with purified human plasmin and plasma plasmin activated with streptokinase, the strong inhibitory action of urinastatin on purified plasmin was demonstrated, but the inhibitory action of urinastatin was decreased markedly in plasma. Therefore, it is suggested that plasma may contain an inhibitory factor against the action of urinastatin.
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PMID:[In vitro observations on antithrombotic action of urinastatin]. 296 16

Suspensions of peripheral blood mononuclear cells (PBMC), monocytes, T or B lymphocytes, platelets or granulocytes, and cell-depleted supernatant fluids of these suspensions inhibited activation of Hageman factor (HF, Factor XII) by ellagic acid, a property not shared by erythrocytes. PBMC also inhibited HF activation by glass or sulfatides. Contaminating platelets may have contributed to inhibition by PBMC. Elaboration of agents inhibiting HF activation required metabolically active cells. The inhibitor(s) in PBMC supernates were not identified with known agents, but had properties of a nonenzymatic protein. PBMC supernates did not contain fibrinogen, nor alter the thrombin, prothrombin, or partial thromboplastin times of normal plasma, amidolysis by activated plasma thromboplastin antecedent (Factor XIa) or activated Stuart factor (Factor Xa) or esterolysis by C1 (C1 esterase); they inhibited plasmin minimally. These experiments suggest that peripheral blood cells may impede intravascular coagulation. Whether this property helps maintain the fluidity of blood is unclear.
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PMID:Inhibition of the activation of Hageman factor (factor XII) by peripheral blood cells. 349 41

To evaluate the effects of chlormadinone acetate upon the coagulation of blood and fibrinolysin systems, 35 healthy, young women voluntarily using some form of birth control were studied. 10 women who served as controls used intrauterine devices; 25 women took either a progestin-estrogen (1 mg norethindrone acetate and 1 mg mestranol) combination or a synthetic progestational agent (0.5 mg chlormadinone acetate) on a coded, double-blind basis. Platelet counts, thrombelastograms, and plasma assays were performed prior to and after 3 and 6 months of treatment. After 3 months, those taking progestin-estrogen showed a highly significant increase toward hypercoagulability in Quick time, Factors II, VII, and X, and increased levels in the thromboplastin generation time (TGT), Factors V and IX, and plasminogen. At 6 months all levels remained elevated except for TGT. Those on chlormadinone acetate had only a slightly significant change toward hypercoagulability in Quick time and Factor VIII, an increase in Factor IX, and a decrease in Factor X. In the control group only TGT was elevated. The progestin alone induced only minimal changes in comparison to the marked rises accompanied with progestin-estrogen therapy.
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PMID:Progestational agents and blood coagulation. IV. Changes induced by progestogen alone. 411 4

The venom of the rhinoceros horned viper (Bitis nasicornis) has been studied in vitro and has been shown to be anticoagulant. This action appeared to be due to an effect on both the extrinsic and intrinsic blood thromboplastin mechanisms. The venom was also proteolytic and in purified caseinolytic systems activated plasminogen, enhanced the activation of plasminogen by streptokinase, and potentiated the action of plasmin. In the euglobulin clot lysis system high concentrations of venom produced inhibition. The crude venom increased platelet adhesiveness but in high concentrations delayed the snowstorm effect in the Chandler's tube system and inhibited platelet adenosine diphosphate reactivity. Passage through carboxymethylcellulose yielded six fractions. One possessed anticoagulant activity, inhibited plasmin, and increased the optical density of platelet-rich plasma. The other five fractions shortened the plasma recalcification time but had no effect on plasmin activity. Four fractions aggregated platelets and enhanced platelet adenosine diphosphate reactivity.
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PMID:Effects of the venom of the rhinoceros horned viper (Bitis nasicornis) on blood coagulation, platelet aggregation, and fibrinolysis. 425 26

A persistent puzzle in our understanding of hemostasis has been the absence of hemorrhagic symptoms in the majority of patients with Hageman trait, the hereditary deficiency of Hageman factor (factor XII). One proposed hypothesis is that alternative mechanisms exist in blood through which plasma thromboplastin antecedent (PTA, factor XI) can become active in the absence of Hageman factor. In order to test this hypothesis, the effect of several proteolytic enzymes, among them thrombin, plasma kallikrein, and trypsin, was tested upon unactivated PTA. PTA was prepared from normal human plasma by Ca(3)(PO(4))(2) adsorption, ammonium sulfate fractionation, and successive chromatography on QAE-Sephadex (twice). Sephadex-G150, and SP-Sephadex. The partially purified PTA was almost all in its native form, with a specific activity of 45-70 U/mg protein; the yield was about 10%. It contained no measurable amounts of other known clotting factors, plasmin, plasminogen, nor IgG. Incubation of PTA with trypsin generated potent clot-promoting activity that corrected the abnormally long clotting time of plasma deficient in Hageman factor or PTA but not in Christmas factor. This clot-promoting agent behaved like activated PTA on gel filtration (apparent molecular weight: 185,000) and was specifically inhibited by an antiserum directed against activated PTA. These data suggested that PTA can be converted into its active form by trypsin. PTA was not activated by thrombin, chymotrypsin, papain, ficin, plasmin, plasma kallikrein, tissue thromboplastin, or C. Trypsin converted PTA to its active form enzymatically. Whether trypsin serves to activate PTA in vivo is not yet clear.
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PMID:Partial purification of plasma thromboplastin antecedent (factor XI) and its activation by trypsin. 426 22

Blood plasma obtained from an individual with abnormal thromboplastin formation, due to deficiency of Fletcher factor, was fully corrected by 2% of normal, Hageman factor- or PTA-deficient plasma. It was also reconstituted by addition of highly purified human or rabbit prekallikrein. The plasma failed to generate kinin upon exposure to kaolin, a defect which was also corrected by addition of prekallikrein. Prekallikrein antigen was not detectable in this plasma. Fletcher factor-deficient plasma did not support the normal generation of PF/dil when dilute plasma was incubated in glass vessels and injected intracutaneously. Small quantities of Fletcher factor-deficient or Hageman factor-deficient plasma corrected the ability of the other to generate PF/dil. The formation of plasmin in dilute, acidified plasma incubated with kaolin was also abnormal in Fletcher factor-deficient plasma. Plasmin generation was normalized by addition of prekallikrein or small quantities of Hageman factor-deficient plasma. The data support the identity of Fletcher factor and prekallikrein.
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PMID:Prekallikrein deficiency in man. 476 50

The effects of the venoms of Naja melanoleuca, Naja nigricollis, and Ophiophagus hannah on blood coagulation, platelet aggregation, and fibrinolysis were studied in vitro. All three venoms were shown to be anticoagulant. This action appeared to be due to an effect on both the extrinsic and blood thromboplastin mechanisms. Platelet aggregation in Chandler's tubes and adenosine diphosphate reactivity were inhibited by the three venoms, although in the case of Ophiophagus hannah venom they were inhibited only with intermediate concentrations. The three venoms possessed proteolytic properties, but when incorporated into purified caseinolytic systems and euglobulin clot lysis systems inhibition of plasmin activity was observed.
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PMID:Effects of three cobra venoms on blood coagulation, platelet aggregation, and fibrinolysis. 581 35


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