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Mechanisms of Thrombosis and Thrombolysis. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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2
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Marchi R, Neerman-Arbez M, Gay V, Mourey G, Fiore M, Mouton C, Gautier P, De Moerloose P, Casini A. Comparison of different activators of coagulation by turbidity analysis of hereditary dysfibrinogenemia and controls. Blood Coagul Fibrinolysis 2021; 32:108-114. [PMID: 33443927 DOI: 10.1097/mbc.0000000000001000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Turbidity analysis is widely used as a quantitative technique in hereditary dysfibrinogenemia. We aimed to compare several coagulation triggers in hereditary dysfibrinogenemia and control plasmas. We included 20 patients with hereditary dysfibrinogenemia, 19 with hotspot mutations Aα Arg35His (n = 9), Aα Arg35Cys (n = 2), γ Arg301His (n = 6), γ Arg301Cys (n = 2), and one with Aα Phe27Tyr, and a commercial pooled normal plasma. Fibrin polymerization was activated by bovine or human thrombin or tissue factor (TF), in the presence or absence of tissue type plasminogen activator. The lag time (min), slope (mOD/s), maximum absorbance (MaxAbs, mOD), and area under the curve (AUCp, OD s) were calculated from the fibrin polymerization curves and the time for 50% clot degradation (T50, min), AUCf (OD s) and the overall fibrinolytic potential from fibrinolysis curves. The lag time was significantly shorter and AUC increased in Aα Arg35His patients with bovine thrombin as compared with human thrombin. The MaxAbs and AUCp were significantly higher in γArg301His patients with bovine thrombin compared with human thrombin. Fibrin polymerization parameters of patients' samples were closer to those of control when assessed with TF compared with both human and bovine thrombin. T50 and overall fibrinolytic potential were similar in all samples regardless of the coagulation trigger used, however, with TF the AUCf of Aα Arg35His and γ Arg301His groups were significantly decreased compared with control. Bovine and human thrombin cannot be used equally for studying fibrin polymerization in hotspot hereditary dysfibrinogenemia or control plasmas.
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Affiliation(s)
- Rita Marchi
- Experimental Medicine, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.,Faculty of Medicine
| | - Marguerite Neerman-Arbez
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Valérie Gay
- Haemophilia Treatment Centre, Centre hospitalier Métropole Savoie, Chambery
| | - Guillaume Mourey
- Haemophilia Treatment Centre, University Hospital of Besançon.,Hemostasis Laboratory, Etablissement Français du Sang, Besançon
| | - Mathieu Fiore
- Service d'Hématologie biologique, CHU de Bordeaux-GH Sud - Hôpital Haut-Lévêque, Bordeaux
| | - Christine Mouton
- Service d'Hématologie biologique, CHU de Bordeaux-GH Sud - Hôpital Haut-Lévêque, Bordeaux
| | | | | | - Alessandro Casini
- Faculty of Medicine.,Division of Angiology and Hemostasis, University Hospitals of Geneva, Geneva, Switzerland
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Nair PM, Pandya SG, Dallo SF, Reddoch KM, Montgomery RK, Pidcoke HF, Cap AP, Ramasubramanian AK. Platelets stored at 4°C contribute to superior clot properties compared to current standard-of-care through fibrin-crosslinking. Br J Haematol 2017; 178:119-129. [PMID: 28580719 DOI: 10.1111/bjh.14751] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/20/2017] [Indexed: 02/05/2023]
Abstract
Currently, platelets for transfusion are stored at room temperature (RT) for 5-7 days with gentle agitation, but this is less than optimal because of loss of function and risk of bacterial contamination. We have previously demonstrated that cold (4°C) storage is an attractive alternative because it preserves platelet metabolic reserves, in vitro responses to agonists of activation, aggregation and physiological inhibitors, as well as adhesion to thrombogenic surfaces better than RT storage. Recently, the US Food and Drug Administration clarified that apheresis platelets stored at 4°C for up to 72 h may be used for treating active haemorrhage. In this work, we tested the hypothesis that cold-stored platelets contribute to generating clots with superior mechanical properties compared to RT-stored platelets. Rheological studies demonstrate that the clots formed from platelets stored at 4°C for 5 days are significantly stiffer (higher elastic modulus) and stronger (higher critical stress) than those formed from RT-stored platelets. Morphological analysis shows that clot fibres from cold-stored platelets were denser, thinner, straighter and with more branch points or crosslinks than those from RT-stored platelets. Our results also show that the enhanced clot strength and packed structure is due to cold-induced plasma factor XIII binding to platelet surfaces, and the consequent increase in crosslinking.
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Affiliation(s)
- Prajeeda M Nair
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.,Blood Research Program, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Shaunak G Pandya
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA
| | - Shatha F Dallo
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA
| | - Kristin M Reddoch
- Blood Research Program, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Robbie K Montgomery
- Blood Research Program, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Heather F Pidcoke
- Blood Research Program, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Andrew P Cap
- Blood Research Program, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
| | - Anand K Ramasubramanian
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, USA.,Department of Biomedical, Chemical and Materials Engineering, San José State University, San José, CA, USA
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4
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Mechanisms of Thrombosis and Thrombolysis. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00002-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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5
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Mechanisms of Thrombosis and Thrombolysis. Stroke 2011. [DOI: 10.1016/b978-1-4160-5478-8.10003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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6
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Abstract
Dengue virus is a mosquito-borne human viral pathogen that has recently become a major public health concern particularly in tropical and subtropical countries, predominantly in urban and periurban areas. Plasma from five patients infected by the virus was selected since they have in different degrees prolonged thrombin times: +2.1, +3.4, +5.7, +7.1 and +18.5 s, like a transitory acquired dysfibrinogenemia. The serotype could be determined in only two patients, being DEN-1 and DEN-3. The fibrinogen concentration was normal ranging from 2.5 to 3.2 g/l. In general, the fibrin degradation products of the patients were high, reaching values of 6000 ng/ml. The polymerization process was quite similar to that of the control, except in two cases where the final turbidity was almost half the control value. In one of these patients, the fibrinogen was purified and mixed with normal fibrinogen (v: v); the patients' fibrinogen impaired normal fibrin polymerization. Studies of the fibrinolytic process revealed that clots from dengue patients started to lyze before they have reached the maximum turbidity, although this was not reflected in the time needed for complete clot dissolution, which was similar to that of the control for all the patients. Fibrinolysis of clots made by mixing normal and patient purified fibrinogen (2.5: 1) was impaired. Clot images obtained by scanning electron microscopy showed that the patients' fibrin network had some degree of degradation and the fibers were thicker than those of the control (P < 0.05). This preliminary study seems to indicate that the dengue virus infection modifies the balance of coagulation-fibrinolysis toward hyperfibrinolysis and could modify the normal fibrinogen molecule.
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7
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Schaefer AVL, Leslie BA, Rischke JA, Stafford AR, Fredenburgh JC, Weitz JI. Incorporation of Fragment X into Fibrin Clots Renders Them More Susceptible to Lysis by Plasmin. Biochemistry 2006; 45:4257-65. [PMID: 16566600 DOI: 10.1021/bi0525730] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bleeding, the most serious complication of thrombolytic therapy with tissue-type plasminogen activator (t-PA), is thought to result from lysis of fibrin in hemostatic plugs and from the systemic lytic state caused by unopposed plasmin. One mechanism by which systemic plasmin can impair hemostasis is by partially degrading fibrinogen to fragment X, a product that retains clottability but forms clots with reduced tensile strength that stimulate plasminogen activation by t-PA more than fibrin clots. The purpose of this study was to elucidate potential mechanisms by which fragment X accelerates t-PA-mediated fibrinolysis. In the presence of t-PA, clots containing fragment X were degraded faster than fibrin clots and exhibited higher rates of plasminogen activation. Although treatment with carboxypeptidase B, an enzyme that reduces plasminogen binding to fibrin, prolonged the lysis times of fragment X and fibrin clots, clots containing fragment X still were degraded more rapidly. Furthermore, plasmin or trypsin also degraded clots containing fragment X more rapidly than fibrin clots, suggesting that this effect is largely independent of plasminogen activation. Fragment X-derived degradation products were not preferentially released by plasmin from clots composed of equal concentrations of fibrinogen and fragment X, indicating that fragment X does not constitute a preferential site for proteolysis. These data suggest that structural changes resulting from incorporation of fragment X into clots promote their lysis. Thus, attenuation of thrombolytic therapy-induced fragment X formation may reduce the risk of bleeding.
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Affiliation(s)
- Amy V L Schaefer
- Department of Medicine, McMaster University, Hamilton, Ontario L8V 1C3, Canada
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del Zoppo GJ, Kalafut M. Mechanisms of Thrombosis and thrombolysis. Stroke 2004. [DOI: 10.1016/b0-44-306600-0/50046-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Meh DA, Mosesson MW, DiOrio JP, Siebenlist KR, Hernandez I, Amrani DL, Stojanovich L. Disintegration and reorganization of fibrin networks during tissue-type plasminogen activator-induced clot lysis. Blood Coagul Fibrinolysis 2001; 12:627-37. [PMID: 11734662 DOI: 10.1097/00001721-200112000-00003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this study, we investigated tissue-type plasminogen activator (tPA)-induced lysis of glutamic acid (glu)-plasminogen-containing or lysine (lys)-plasminogen-containing thrombin-induced fibrin clots. We measured clot development and plasmin-mediated clot disintegration by thromboelastography, and used scanning electron microscopy (SEM) to document the structural changes taking place during clot formation and lysis. These events occurred in three overlapping stages, which were initiated by the addition of thrombin, resulting first in fibrin polymerization and clot network organization (Stage I). Autolytic plasmin cleavage of glu-plasminogen at lys-77 generates lys-plasminogen, exposing lysine binding sites in its kringle domains. The presence of lys-plasminogen within the thrombin-induced fibrin clot enhanced network reorganization to form thicker fibers as well as globular complexes containing fibrin and lys-plasminogen having a greater level of turbidity and a higher elastic modulus (G) than occurred with thrombin alone. Lys-plasminogen or glu-plasminogen that had been incorporated into the fibrin clot was activated to plasmin by tPA admixed with the thrombin, and led directly to clot disintegration (Stage II) concomitant with fibrin network reorganization. The onset of Stage III (clot dissolution) was signaled by a sustained secondary rise in turbidity that was due to the combined effects of lys-plasminogen presence or its conversion from glu-plasminogen, plus clot network reorganization. SEM images documented dynamic structural changes in the lysing fibrin network and showed that the secondary turbidity rise was due to extensive reorganization of severed fibrils and fibers to form wide, occasionally branched fibers. These degraded structures contributed little, if anything, to the structural integrity of the residual clot, and eventually collapsed completely during the course of progressive clot dissolution. These results provide new perspectives on the major structural events that occur in the fibrin clot matrix during fibrinolysis.
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Affiliation(s)
- D A Meh
- The Blood Research Institute of The Blood Center of Southeastern Wisconsin, Milwaukee, Wisconsin 53201-2178, USA
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Fatah-Ardalani K, Wallén P, Petersen LC, Blombäck M. More porous fibrin gel structure obtained by interaction with Lys-plasminogen than with Glu-plasminogen. Blood Coagul Fibrinolysis 2000; 11:335-42. [PMID: 10847420 DOI: 10.1097/00001721-200006000-00004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effect of Glu1- and Lys78-plasminogen on the assembly and structure of fibrin gels was studied in purified fibrinogen-thrombin system and in plasminogen-free plasma, using turbidity, liquid permeation and three-dimensional (3D) confocal laser microscopy methods. In the purified fibrinogen system using the turbidity method, the final optical density of the fibrin gels increased with increasing concentrations of Lys-plasminogen. The fiber mass/length ratio mu increased with increasing concentrations of both Glu1- and Lys78-plasminogen, the effect of Lys78-plasminogen being much stronger. The permeability coefficient (Ks) analyzed with the permeation method revealed that fibrin gels formed in the presence of Lys78-plasminogen were more permeable (porous) than the control gels. The effect on the gel structure was inhibited by the fibrinolytic inhibitor epsilon-aminocaproic acid. The same results were obtained in plasma milieu for both mu and Ks as in the purified system, i.e. the gels became more porous with increasing concentrations of Lys78-plasminogen. 3D microscopy pictures of the gels verified the findings.
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Affiliation(s)
- K Fatah-Ardalani
- Department of Laboratory Medicine/Coagulation Research, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden
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Abstract
Fibrin is degraded by the fibrinolytic system in which a plasminogen activator converts plasminogen to plasmin, a serine protease that cleaves specific bonds in fibrin leading to solubilization. To elucidate further the biophysical processes involved in conversion of insoluble fibers to soluble fragments, fibrin was treated with either plasmin or the combination of plasminogen and plasminogen activator, and morphologic changes were observed using scanning electron microscopy. These changes were correlated with biochemical analysis and with characterization of released, soluble fragments by transmission electron microscopy. Initial changes in the fibrin matrix included creation of many free fiber ends and gaps in the continuity of fibers. With more extensive digestion, free fiber segments associated laterally, resulting in formation of thick fiber bundles. Supernatants of digesting clots, containing soluble derivatives, were negatively contrasted and examined by transmission electron microscopy. Large, complex fragments containing portions of multiple fibers were observed, as were pieces of individual fibers and smaller fragments previously identified. Some large fragments had sharply defined ends, indicating that they had been cleaved perpendicularly to the fiber direction. Other fibers showed splayed ends or a lacy meshwork of surrounding protofibrils. Longer times generated more small fragments whose molecular composition could be inferred from their appearance. These results indicate that fibrinolytic degradation results in larger pieces than previously identified and that plasmin digestion proceeds locally by transverse cutting across fibers rather than by progressive cleavage uniformly around the fiber.
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12
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Abstract
AbstractFibrin is degraded by the fibrinolytic system in which a plasminogen activator converts plasminogen to plasmin, a serine protease that cleaves specific bonds in fibrin leading to solubilization. To elucidate further the biophysical processes involved in conversion of insoluble fibers to soluble fragments, fibrin was treated with either plasmin or the combination of plasminogen and plasminogen activator, and morphologic changes were observed using scanning electron microscopy. These changes were correlated with biochemical analysis and with characterization of released, soluble fragments by transmission electron microscopy. Initial changes in the fibrin matrix included creation of many free fiber ends and gaps in the continuity of fibers. With more extensive digestion, free fiber segments associated laterally, resulting in formation of thick fiber bundles. Supernatants of digesting clots, containing soluble derivatives, were negatively contrasted and examined by transmission electron microscopy. Large, complex fragments containing portions of multiple fibers were observed, as were pieces of individual fibers and smaller fragments previously identified. Some large fragments had sharply defined ends, indicating that they had been cleaved perpendicularly to the fiber direction. Other fibers showed splayed ends or a lacy meshwork of surrounding protofibrils. Longer times generated more small fragments whose molecular composition could be inferred from their appearance. These results indicate that fibrinolytic degradation results in larger pieces than previously identified and that plasmin digestion proceeds locally by transverse cutting across fibers rather than by progressive cleavage uniformly around the fiber.
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Sundell IB, Marzec UM, Kelly AB, Chronos NA, Petersen LC, Hanson SR, Hedner U, Harker LA. Reduction in stent and vascular graft thrombosis and enhancement of thrombolysis by recombinant Lys-plasminogen in nonhuman primates. Circulation 1997; 96:941-8. [PMID: 9264505 DOI: 10.1161/01.cir.96.3.941] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND To enhance thrombolytic responses without increasing hemorrhagic risks, the antithrombotic effects of recombinant Lys-plasminogen (r-LysPgn), a prothrombolytic plasminogen intermediate, were examined in baboon models of thrombus formation and dissolution. METHODS AND RESULTS The dose-response effects of r-LysPgn, alone or in combination with subthreshold dosing of tissue plasminogen activator (TPA), were measured with respect to the accumulation of (111)In-labeled platelets and (125)I-fibrin in thrombus forming on endovascular metallic stents or thrombogenic segments of vascular graft interposed in exteriorized long-term arteriovenous (AV) femoral shunts. Thrombolytic losses have also been determined for preformed, stable, (111)In-platelet- and (125)I-fibrin-labeled graft thrombus and corresponding propagated thrombotic tails, together with changes in blood tests of thrombosis, thrombolysis, and hemostasis. Bolus intravenous r-LysPgn in escalating doses (2, 4, or 8 mg/kg) increased circulating plasminogen levels in a dose-dependent manner, was removed by log-linear clearance with a T50 of 120 minutes, and reciprocally decreased the accumulating thrombus on metallic stents and segments of vascular graft (P<.001 in all cases for 8-mg/kg doses). r-LysPgn also impaired platelet aggregatory responses to physiological agonists in vitro but not ex vivo. Prethrombosis administration of low-dose r-LysPgn (2 mg/kg) greatly enhanced the lysis of radiolabeled nonoccluding thrombus by a subthreshold dose of TPA (0.1 mg/kg) compared with TPA-only controls (P=.03). CONCLUSIONS Elective bolus injections of r-LysPgn before stent deployment decrease the amount of thrombus formed without compromising hemostasis by facilitating endogenous TPA thrombolysis. r-LysPgn may provide effective and safe antithrombotic therapy for interventional vascular procedures.
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Affiliation(s)
- I B Sundell
- Department of Medicine, Yerkes Regional Primate Research Center, Emory University School of Medicine, Atlanta, GA 30322, USA
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Sakharov DV, Nagelkerke JF, Rijken DC. Rearrangements of the fibrin network and spatial distribution of fibrinolytic components during plasma clot lysis. Study with confocal microscopy. J Biol Chem 1996; 271:2133-8. [PMID: 8567670 DOI: 10.1074/jbc.271.4.2133] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Binding of components of the fibrinolytic system to fibrin is important for the regulation of fibrinolysis. In this study, decomposition of the fibrin network and binding of plasminogen and plasminogen activators (PAs) to fibrin during lysis of a plasma clot were investigated with confocal microscopy using fluorescein-labeled preparations of fibrinogen, plasminogen, tissue-type PA (t-PA), and two-chain urokinase-type PA (tcu-PA). Lysis induced by PAs present throughout the plasma clot was accompanied by a gradual loss of fibrin content of fibers and by accumulation of plasminogen onto the fibers. Two sequential phases could be distinguished: a phase of prelysis, during which the fibrin network remained immobile, and a phase of final lysis, during which fibers moved with a tendency to shrink and eventually disappeared. The two phases occurred simultaneously but in different locations when lysis was induced by PAs present in the plasma surrounding the clot. The zone of final lysis was located within a 5-8 microns superficial layer, where fibers were mobile, a surface-associated fibrin agglomerates appeared. Plasminogen accumulated in these agglomerates up to 30-fold as compared with its concentration in the outer plasma. t-PA was also highly concentrated in the agglomerates, and tcu-PA bound to them slightly. The zone of prelysis, where plasminogen was moderately accumulated on the immobile fibers, was located deeper in the clot. This zone was much thinner in the case of t-PA-induced lysis than in the case of tcu-PA-induced lysis, reflecting the difference in penetration of the two PAs into the clot. We conclude that under conditions of diffusional transport of fibrinolytic enzymes from outside a plasma clot, extensive lysis is spatially restricted to a zone not exceeding 5-8 microns from the clot surface. In this zone the structure of the fibrin network undergoes significant changes, and strikingly high accumulation of fibrinolytic components takes place.
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Affiliation(s)
- D V Sakharov
- Gaubius Laboratory, TNO-PG, Leiden, The Netherlands
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Mehta JL, Chen L, Nichols WW, Johannesen M, Bregengård C, Hedner U, Saldeen TG. Recombinant lys-plasminogen, but not glu-plasminogen, improves recombinant tissue-type plasminogen activator-induced coronary thrombolysis in dogs. J Am Coll Cardiol 1995; 25:753-60. [PMID: 7860925 DOI: 10.1016/0735-1097(94)00444-u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES This study examined the modification of recombinant tissue-type plasminogen activator (rt-PA)-induced thrombolysis by recombinant lys-plasminogen. BACKGROUND Recombinant tissue-type plasminogen activator restores flow in the thrombosed coronary artery, but the artery often reoccludes. The rt-PA-induced thrombolysis is a result of activation of plasminogen bound to fibrin in the thrombus and results in generation of the fibrinolytic enzyme plasmin. Small amounts of lys-plasminogen are formed when rt-PA is used. Lys-plasminogen binds to fibrin with a 10-fold greater affinity than the predominant native glu-plasminogen, leading to a loose fibrin structure. METHODS Dogs with electrically induced occlusive intracoronary thrombus were treated with saline solution (n = 9), glu-plasminogen (2 mg/kg body weight, n = 5) or lys-plasminogen (2 mg/kg, n = 5), followed by infusion of rt-PA (1 mg/kg over 20 min) 10 min later. RESULTS Reperfusion rates were similar in all groups of dogs, but the time to reflow was lowest in dogs given lys-plasminogen compared with those given saline solution or glu-plasminogen before rt-PA (mean [+/- SE] 14 +/- 2 vs. 22 +/- 2 and 23 +/- 3 min, respectively, p < 0.05). None of the reperfused coronary arteries reoccluded in the lys-plasminogen plus rt-PA group, whereas 75% reoccluded in dogs given saline solution plus rt-PA, and 50% reoccluded in those given glu-plasminogen plus rt-PA. Accordingly, duration of reflow was greater in the lys-plasminogen plus rt-PA group (> 120 vs. 39 +/- 7 and 82 +/- 21 min, respectively, p < 0.05). Plasminogen activator inhibitor-1 activity decreased during rt-PA infusion and thereafter increased in all dogs, but less so in dogs given lys-plasminogen (p < 0.05 vs. those given saline solution before rt-PA). CONCLUSIONS Treatment with recombinant lys-plasminogen before rt-PA reduces time to reflow and sustains reflow after thrombolysis, whereas glu-plasminogen has no such effect.
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Affiliation(s)
- J L Mehta
- Department of Medicine, University of Florida College of Medicine, Gainesville 32610-0277
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