Thrombin Generation Induced by the Intrinsic or Extrinsic Coagulation Pathway is Accelerated by Streptokinase, Independently of Plasminogen

1993 ◽  
Vol 70 (06) ◽  
pp. 0995-0997 ◽  
Author(s):  
E J P Brommer ◽  
P Meijer
Keyword(s):  
Plasminogen Activator ◽  
Thrombin Generation ◽  
Degradation Products ◽  
Recombinant Tissue Plasminogen Activator ◽  
Chromogenic Substrate ◽  
Extrinsic Pathway ◽  
Calcium Dependent ◽  
Thrombolytic Agents ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator

SummaryThrombolytic therapy paradoxically induces the formation of fibrinopeptide A, fibrin degradation products and thrombin-antithrombin complexes, indicating thrombin generation. Part of the mechanism of this thrombin generation under the influence of thrombolytic agents was unraveled in this study.We measured thrombin with a chromogenic substrate at several time intervals after recalcification of citrated plasma which had been preincubated with urokinase, streptokinase, recombinant tissue plasminogen activator (rt-PA) or recombinant singlechain urokinase-type plasminogen activator (rscu-PA). Thrombin generation induced by the addition of thromboplastin together with calcium (extrinsic pathway) was greatly accelerated in the presence of streptokinase (from about 7 to 2 min), and to a lesser extent in the presence of urokinase, rt-PA or rscu-PA. Similar effects were seen after the addition of calcium to the plasma containing the thrombolytic agent and preincubated with partial thromboplastin (intrinsic pathway). Hirudin quenched the conversion of the chromogenic substrate completely, confirming that thrombin was the active enzyme. Aprotinine did not affect the results, and the effect of streptokinase was also observed in plasminogen-depleted plasma. We conclude that streptokinase, and to a lesser extent other thrombolytic agents, activate the prothrombinase complex directly or indirectly through a calcium-dependent mechanism, independently of plasminogen, with a resulting acceleration of thrombin generation.

scholarly journals Relationship Between Severity of Fibrinolysis Based on Rotational Thromboelastometry and Conventional Fibrinolysis Markers

2020 ◽  
Vol 26 ◽  
pp. 107602962093300
Author(s):  
Tomoyo Saito ◽  
Mineji Hayakawa ◽  
Yoshinori Honma ◽  
Asumi Mizugaki ◽  
Tomonao Yoshida ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Degradation Products ◽  
Plasminogen Activator Inhibitor ◽  
University Hospital ◽  
Extrinsic Pathway ◽  
Rotational Thromboelastometry ◽  
Fibrin Degradation Products ◽  
Pi Complex ◽  
Fibrinolytic Parameters ◽  
Hospital Cardiac Arrest

The association between severity of fibrinolysis, ascertained by rotational thromboelastometry to diagnose hyperfibrinolysis in patients with out-of-hospital cardiac arrest (OHCA), and conventional fibrinolysis markers (ie, tissue-plasminogen activator [t-PA], plasminogen, α2-plasmin inhibitor [α2-PI], and plasminogen activator inhibitor [PAI]) with key roles in the fibrinolytic system was investigated. This prospective observational study included 5 healthy volunteers and 35 patients with OHCA from the Hokkaido University Hospital. Blood samples were drawn immediately upon admission to the emergency department. Assessments of the extrinsic pathway using tissue factor activation (EXTEM) and of fibrinolysis by comparison with EXTEM after aprotinin addition (APTEM) were undertaken. Conventional coagulation and fibrinolysis markers were measured in the stored plasma samples. Significant hyperfibrinolysis observed in EXTEM disappeared in APTEM. Patients exhibited significantly higher levels of fibrinogen/fibrin degradation products, plasmin–α2-PI complex, and t-PA but lower levels of fibrinogen, plasminogen, and α2-PI than healthy controls. The PAI level was unchanged. Fibrinolytic parameters of EXTEM correlated with levels of lactate and conventional fibrinolysis markers, especially t-PA. Increased t-PA activity and decreased plasminogen and α2-PI significantly correlated with increased severity of fibrinolysis (hyperfibrinolysis).

Fibrin Metabolism in Patients with Acute Myocardial Infarction During and After Treatment with Tissue-Type Plasminogen Activator

1988 ◽  
Vol 60 (03) ◽  
pp. 428-433 ◽  
Author(s):  
Michael E Ring ◽  
Samuel M Butman ◽  
Denise C Bruck ◽  
William M Feinberg ◽  
James J Corrigan
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Molecular Markers ◽  
Plasminogen Activator ◽  
Degradation Products ◽  
Fibrinolytic Therapy ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator

SummaryIn order to define some of the determinants of successful thrombolysis and reocclusion during fibrinolytic therapy for acute myocardial infarction (AMI), specific molecular markers of fibrin metabolism were serially measured in 15 patients with AMI treated with tissue-type plasminogen activator (t-PA). Fibrin formation was assessed by measurement of fibrinopeptide A (FpA) and fibrinolysis by assay of B-P peptides 1—42 and 15—42 and crosslinked fibrin degradation products (XDP). At baseline, FpA levels were high while markers of fibrinolysis were near normal. Following a 90-minute infusion of t-PA (0.5—1.1 mg kg−1 hr−1), all markers of fibrinolysis increased. Levels of FpA remained elevated despite heparin at the initiation of cardiac catheterization. None of these markers discriminated between patients with successful reperfusion from those without. At 4 hours, B-β 15—42 peptide and XDP levels remained elevated suggesting persistence of fibrinolysis beyond the short circulatory half-life of t-PA. FpA levels at 4 hours were lower in patients who underwent acute coronary angioplasty compared to those who received additional low dose t-PA (12.3 ± 4.5 vs. 30.4 ± 5.5 ng/ ml, p <0.05). By 48 hours, markers of fibrinolysis had returned toward normal except in 2 patients with persistently elevated B-P 15—42 peptide levels who suffered reocclusion on days 5 and 6 (75 and 44 vs. 29 ± 3 nM, p <0.005). In conclusion, molecular markers of fibrin metabolism during fibrinolytic therapy may provide clinically relevant data.

D-Phe-Pro-Arg-Chloromethylketone: Its Potential Use in Inhibiting the Formation of In Vitro Artifacts in Blood Collected During Tissue-Type Plasminogen Activator Thrombolytic Therapy

1986 ◽  
Vol 56 (02) ◽  
pp. 160-164 ◽  
Author(s):  
M A Mohler ◽  
C J Refino ◽  
S A Chen ◽  
A B Chen ◽  
A J Hotchkiss
Keyword(s):  
Plasminogen Activator ◽  
Degradation Products ◽  
Significant Loss ◽  
Tissue Type ◽  
Blood Samples ◽  
Tissue Type Plasminogen Activator ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Potential Use

Summary In vitro artifacts due to proteolysis may occur in blood samples containing recombinant tissue-type plasminogen activator (rt-PA) due to continued activation of plasminogen to plasmin by rt-PA. The aim of this study was to identify a rapid inhibitor of rt-PA that would not interfere in assays designed to monitor thrombolytic events.When rt-PA was added at 5 μg/ml to whole blood and incubated at 25° C, fibrinogen decreased 50 percent, plasminogen levels decreased 90 percent and α2-antiplasmin decreased below detectable levels. If D-Phe-Pro-Arg-chloromethylketone (PPACK) or aprotinin were added before the addition of rt-PA there was no significant loss of fibrinogen. Only PPACK completely inhibited changes in fibrin degradation products, plasminogen and α2-antiplasmin. PPACK was also found to inhibit the binding of rt-PA to plasma protease inhibitors in vitro.Rhesus monkeys were infused with rt-PA and blood samples were taken with either PPACK or aprotinin in the collection syringe. There was a significant increase in the recovery of immunoreactive rt-PA and consistent measures of fibrinogen, FDPs, plasminogen, and α2-antiplasmin in the PPACK group as compared to the aprotinin group which indicates that PPACK will prevent the in vitro formation of artifacts due to the presence of active rt-PA

Structural Studies of Fibrinolysis by Electron and Light Microscopy

1999 ◽  
Vol 82 (08) ◽  
pp. 277-282 ◽  
Author(s):  
Yuri Veklich ◽  
Jean-Philippe Collet ◽  
Charles Francis ◽  
John W. Weisel
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Plasminogen Activator ◽  
Structural Changes ◽  
Molecular Mechanisms ◽  
Degradation Products ◽  
Molecular Model ◽  
Three Dimensional ◽  
Tissue Type ◽  
Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

A Monoclonal Antibody-Based Enzyme Immunoassay for Fibrin Degradation Products in Plasma

1988 ◽  
Vol 59 (02) ◽  
pp. 310-315 ◽  
Author(s):  
P W Koppert ◽  
E Hoegee-de Nobel ◽  
W Nieuwenhuizen
Keyword(s):  
Enzyme Immunoassay ◽  
Degradation Products ◽  
Blood Clot ◽  
Tissue Type ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Strong Positive Reaction ◽  
Sandwich Type ◽  
Capture Antibody

SummaryWe have developed a sandwich-type enzyme immunoassay (EIA) for the quantitation of fibrin degradation products (FbDP) in plasma with a time-to-result of only 45 minutes.* The assay is based on the combination of the specificities of two monoclonal antibodies (FDP-14 and DD-13), developed in our institute. FDP-14, the capture antibody, binds both fibrinogen degradation products (FbgDP) and FbDP, but does not react with the parent fibrin(ogen) molecules. It has its epitope in the E-domain of the fibrinogen molecule on the Bβ-chain between amino acids 54-118. Antibody DD-13 was raised using D-dimer as antigen and is used as a tagging antibody, conjugated with horse-radish peroxidase. A strong positive reaction is obtained with a whole blood clot lysate (lysis induced by tissue-type plasminogen activator) which is used as a standard. The EIA does virtually not detect FbgDP i. e. purified fragments X, Y, or FbgDP generated in vitro in plasma by streptokinase treatment. This indicates that the assay is specific for fibrin degradation products.We have successfully applied this assay to the plasma of patients with a variety of diseased states. In combination with the assay previously developed by us for FbgDP and for the total amount of FbgDP + FbDP (TDP) in plasma, we are now able to study the composition of TDP in patients plasma in terms of FbgDP and FbDP.

Enhanced Effective Fibrinolysis following the Neutralization of Heparin in Open Heart Surgery Increases the Risk of Post-Surgical Bleeding

1990 ◽  
Vol 63 (02) ◽  
pp. 241-245 ◽  
Author(s):  
Jørgen Gram ◽  
Thomas Janetzko ◽  
Jørgen Jespersen ◽  
Hans Dietrich Bruhn
Keyword(s):  
Blood Loss ◽  
Plasminogen Activator ◽  
Heart Surgery ◽  
Degradation Products ◽  
Open Heart Surgery ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Chest Tube Drain ◽  
Median Blood Loss

SummaryThe tissue-type plasminogen activator related fibrinolytic system was studied in 24 patients undergoing cardiopulmonary bypass surgery. The degradation of fibrinogen and fibrin was followed during and after surgery by means of new sensitive and specific assays and the changes were related to the blood loss measured in the chest tube drain during the first 24 postoperative hours. Although tissue-type plasminogen activator was significantly released into the circulation during the period of extracor-poreal circulation (p <0.01), constantly low levels of fibrinogen degradation products indicated that a systemic generation of plasmin could be controlled by the naturally occurring inhibitors. Following extracorporeal circulation heparin was neutralized by protamine chloride, and in relation to the subsequent generation of fibrin, there was a short period with increased concentrations of fibrinogen degradation products (p <0.01) and a prolonged period of degradation of cross-linked fibrin, as detected by increased concentrations of D-Dimer until 24 h after surgery (p <0.01). Patients with a higher than the median blood loss (520 ml) in the chest tube drain had a significantly higher increase of D-Dimer than patients with a lower than the median blood loss (p <0.05).We conclude that the incorporation of tissue-type plasminogen activator into fibrin and the in situ activation of plasminogen enhance local fibrinolysis, thereby increasing the risk of bleeding in patients undergoing open heart surgery

Exercise-Induced Fibrinolysis – Fact or Fiction?

1982 ◽  
Vol 48 (02) ◽  
pp. 201-203 ◽  
Author(s):  
N A Marsh ◽  
P J Gaffney
Keyword(s):  
Plasminogen Activator ◽  
Degradation Products ◽  
Coagulation Factors ◽  
Vascular Wall ◽  
Strenuous Exercise ◽  
Fibrin Degradation Products ◽  
Real Increase ◽  
Exercise Induced ◽  
Male Subjects

SummaryThe effect of strenuous exercise on the fibrinolytic and coagulation mechanisms was examined in six healthy male subjects. Five min bicycle exercise at a work-rate of 800 to 1200 kpm. min−1 produced an abrupt increase in plasma plasminogen activator levels which disappeared after 90 min. However, there was no change in early or late fibrin degradation products nor was there a change in fibrinopeptide A levels or βthromboglobulin levels after exercise although activated partial thromboplastin times were significantly shortened. It is concluded that strenuous exercise does not produce any real increase in fibrinogen-fibrin conversion nor any real increase in the breakdown of these proteins. The role of exercise-induced release of plasminogen activator remains unclear, but probably helps to maintain plasma levels in a discontinuous manner concurrently with the continuous low-level secretion from the vascular wall. The shortening of partial thromboplastin time may be due to the raised levels of plasminogen activator changing the activation state of other coagulation factors.

The Pathogenesis of Thrombotic Thrombocytopenic Purpura

1979 ◽  
Author(s):  
H. C. Kwaan
Keyword(s):  
Plasminogen Activator ◽  
Thrombotic Thrombocytopenic Purpura ◽  
Degradation Products ◽  
Vascular Lesions ◽  
Local Defect ◽  
Laboratory Findings ◽  
Thrombocytopenic Purpura ◽  
Fibrin Degradation Products ◽  
Severity Of The Disease ◽  
Circulating Levels

The vascular lesions with microthrombi were studied in 12 patients with thrombotic thrombocytopenic purpura (TTP), diagnosed by the characteristic clinical and laboratory findings and confirmed histologically in each case. While defibrination was not observed, and with only minimal changes in the circulating levels of fibrinogen, fibrin degradation products and plasminogen activator, the microthrombotic lesion was invariably present. Immunofluorescent and histochemical studies indicated that both platelet and fibrin were present in the microthrombi with the platelet components dominant in many cases. Using the fibrin slide method, plasminogen activator was demonstrated in the uninvolved blood vessels but totally absent in the vessels occluded by microthrombi. in contrast, fibrinolysis is always present in the vessels afflicted with other types of thrombosis, such as the microthrombi in disseminated intravascular coagulation. Since circulating fibrinolytic activity was normal in TTP, the absence of vascular fibrinolysis is a local defect due to either inhibition by the platelet deposits or by local vascular damage. The inability of thrombolysis may explain the absence of systemic defibrination and the severity of the disease.

Pharmacokinetics and Effects on Fibrinolytic and Coagulation Parameters of Two Doses of Recombinant Tissue-Type Plasminogen Activator in Healthy Volunteers

1986 ◽  
Vol 56 (01) ◽  
pp. 001-005 ◽  
Author(s):  
M Verstraete ◽  
C A P F Su ◽  
P Tanswell ◽  
W Feuerer ◽  
D Collen
Keyword(s):  
Healthy Volunteers ◽  
Plasminogen Activator ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
State Level ◽  
Compartment Model ◽  
Tissue Type ◽  
Maximum Plasma ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryPharmacokinetics and pharmacological effects of two intravenous doses of recombinant tissue-type plasminogen activator (rt-PA) (40 and 60 mg over 90 min) were determined in healthy volunteers. Mean maximum plasma concentrations were 1080 and 1560 ng/ml respectively. The steady state level during subsequent maintenance infusion of 30 mg over 6 h was 250 ng/ml. The pharmacokinetics of rt-PA showed a bi-exponential disappearance from plasma consistent with a 2-compartment model of t½α = 5.7 min, a t½β = 1.3 h and a total clearance of 380 ml/min.Mean fibrinogen levels at the end of the infusions of 40 mg or 60 mg rt-PA over 90 min, measured in thawed plasma samples collected on citrate/aprotinin, decreased to 74% and 57% of the preinfusion values respectively. Plasminogen fell to 55% and 48%, and α2-antiplasmin to 28% and 18% of initial values. No further decrease of these parameters was observed during the infusion of 30 mg rt-PA over 6 h. Only 2% of the preinfusion fibrinogen levels could be recovered as fibrinogen-fibrin degradation products. This moderate extent of systemic fibrinogenolysis is much less than that reported for therapeutic i.v. infusions of streptokinase.

PLASMA LEVELS OF FRAGMENT D-DIMER OF CROSSLINKED FIBRIN DURING THROMBOLYTIC THERAPY WITH RECOMBINANT TISSUE-TYPE PLASMINOGEN ACTIVATOR

1987 ◽  
Author(s):  
P Declerck ◽  
P Mombaerts ◽  
P Holvoet ◽  
D Collen
Keyword(s):  
Thrombolytic Therapy ◽  
Plasma Levels ◽  
Degradation Products ◽  
Fibrin Clot ◽  
Tissue Type ◽  
Fibrin Degradation Products ◽  
Type Plasminogen Activator ◽  
Rate Of Increase ◽  
Significant Difference ◽  
D Dimer

Plasma levels of crosslinked fibrin degradation products (XLDP) were measured before and at the end of the administration of rt-PA (40 to 100 mg over 1.5 to 8 hours) in healthy volunteers (n=5) and patients with deep venous thrombosis (DVT) (n=8), pulmonary embolism (PE) (n=16)and myocardial infarction(MI)(n=10). Determinations were performed using our newly developed ELISA, specific for crosslinked fibrin derivatives, based on two monoclonal antibodies (15C5 and 8D3H2) raised against purified human fragment D-dimer. All plasma samples were collected on citrate and trasylol. Results are expressed as mean and range of D-dimer equivalents (μg/ml).Baseline levels in patients with MI are only slightly elevated. The increased levels inDVT and PE are in agreement with previous studies. After infusion of rt-PA a small increase of XLDP is seen even innormal subjects. A very marked increasof XLDP is detected in patients with PE and DVT but not in patients with MI. This may reflect differences in the amounts of fibrin clot dissolved in these patient groups.No significant correlation was found between the increase of XLDP and success of therapy, although a significant difference in D-dimer levels was formed between the two groups with PE: successful (n=ll): 116 (range 61-192) vs. unsuccessful (n=5): 68 (36-155).Thus, XLDP are already elevated under baseline conditions in patients with DVT and PE and increase very markedly during thrombolytic therapy. The absolute levels after thrombolytic therapy do not strictly correlate with success of therapy. It could be useful to measure D-dimer levels during early stages of therapy, because the rate of increase of XLDP levels might correlate with the efficacy of thrombolytic treatment.

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