scholarly journals The pathogenesis of accelerated fibrinolysis in liver cirrhosis: a critical role for tissue plasminogen activator inhibitor

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1315-1319 ◽  
Author(s):  
SL Hersch ◽  
T Kunelis ◽  
RB Jr Francis
Keyword(s):  
Liver Cirrhosis ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Blood Clot ◽  
Critical Role ◽  
Plasminogen Activator Inhibitor ◽  
Clot Lysis ◽  
Lysis Time ◽  
Tissue Plasminogen

Abstract The pathogenesis of accelerated fibrinolysis in liver cirrhosis was investigated by comparing the results of specific assays for tissue plasminogen activator (tpa) antigen, tpa activity, tpa inhibitor, and alpha-2 plasmin inhibitor (a2PI) in 12 patients with cirrhosis and markedly accelerated fibrinolysis (dilute whole blood clot lysis time (DWBCLT) less than two hours), in nine patients with cirrhosis and moderately accelerated fibrinolysis (DWBCLT two to four hours), and in nine patients with cirrhosis and normal fibrinolysis (DWBCLT greater than four hours). Mean tpa antigen was markedly increased in all three groups, but no correlation was observed between overall fibrinolytic activity as measured by the DWBCLT and the level of tpa antigen. In contrast, there was a significant correlation between overall fibrinolytic activity and tpa activity and an equally significant correlation between fibrinolytic activity and decreased tpa inhibition. Mean a2PI activity was significantly lower than normal in groups 1 and 2 but was normal in group 3. The pathogenesis of accelerated fibrinolysis in liver cirrhosis thus appears to depend critically on the capacity of plasma inhibitors to inhibit increased circulating tpa antigen. Reduced a2PI also appears to play a role.

scholarly journals The pathogenesis of accelerated fibrinolysis in liver cirrhosis: a critical role for tissue plasminogen activator inhibitor

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1315-1319
Author(s):  
SL Hersch ◽  
T Kunelis ◽  
RB Jr Francis
Keyword(s):  
Liver Cirrhosis ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Blood Clot ◽  
Critical Role ◽  
Plasminogen Activator Inhibitor ◽  
Clot Lysis ◽  
Lysis Time ◽  
Tissue Plasminogen

The pathogenesis of accelerated fibrinolysis in liver cirrhosis was investigated by comparing the results of specific assays for tissue plasminogen activator (tpa) antigen, tpa activity, tpa inhibitor, and alpha-2 plasmin inhibitor (a2PI) in 12 patients with cirrhosis and markedly accelerated fibrinolysis (dilute whole blood clot lysis time (DWBCLT) less than two hours), in nine patients with cirrhosis and moderately accelerated fibrinolysis (DWBCLT two to four hours), and in nine patients with cirrhosis and normal fibrinolysis (DWBCLT greater than four hours). Mean tpa antigen was markedly increased in all three groups, but no correlation was observed between overall fibrinolytic activity as measured by the DWBCLT and the level of tpa antigen. In contrast, there was a significant correlation between overall fibrinolytic activity and tpa activity and an equally significant correlation between fibrinolytic activity and decreased tpa inhibition. Mean a2PI activity was significantly lower than normal in groups 1 and 2 but was normal in group 3. The pathogenesis of accelerated fibrinolysis in liver cirrhosis thus appears to depend critically on the capacity of plasma inhibitors to inhibit increased circulating tpa antigen. Reduced a2PI also appears to play a role.

PHYSICAL ACTIVITY RELEASES TISSUE PLASMINOGEN ACTIVATOR FROM EXERCISING PARTS OF BODY

1987 ◽  
Author(s):  
I Keber ◽  
K Potisk ◽  
D Keber ◽  
M Stegnar ◽  
N Vene
Keyword(s):  
Physical Activity ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Venous Occlusion ◽  
Clot Lysis ◽  
Lysis Time ◽  
Tissue Plasminogen ◽  
Euglobulin Clot Lysis Time ◽  
The Difference

To determine the origin of tissue plasminogen activator (t-PA) release during physical activity, we studied the separate and combined effects of venous occlusion and acute physical activity on t-PA release in arm and leg. In 15 healthy volunteers 20 min venous occlusions of arm and leg were performed simultaneously before physical activity ( maximal stress testing on treadmill)(occlusion I), immediately after physical activity and 45 min later (occlusion II). Blood samples were drawn from unoccluded arm before occlusion and after physical activity, and from occluded arm and leg after occlusion. Fibrinolytic activity was measured by euglobulin clot lysis time (ECLT) and t-PA activity assay. The amount of released t-PA during different stimuli (fibrinolytic potential) was calculated as the difference between post- and prestimulation fibrinolytic activity. Before physical activity there was a great increase in fibrinolytic activity due to t-PA in the occluded arm but no increase in the occluded leg. Physical activity itself caused a similar increase of systemic fibrinolytic activity as arm occlusion locally. After physical activity arm occlusion evoked equally good response than before it. Fibrinolytic activity during leg occlusion behaved differently: there was an increase in t-PA activity in the occluded leg which persisted one hour after physical activity, when systemic fibrinolytic activity already fell to initial level.These results demonstrated that walking and running triggered t-PA release from the leg vessels. Since leg occlusion was not a stimulus for t-PA release, it served only as a method to demonstrate the effect of physical activity.

scholarly journals Severe SARS-CoV-2 infection inhibits fibrinolysis leading to changes in viscoelastic properties of blood clot: A descriptive study of fibrinolysis

2021 ◽  
Author(s):  
Stefanie Hammer ◽  
Helene Haeberle ◽  
Christian Schlensak ◽  
Michael Bitzer ◽  
Nisar Malek ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Point Of Care ◽  
Blood Clot ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Blood Samples ◽  
Lysis Time ◽  
Tissue Plasminogen ◽  
Pai 1

Background: Accumulating evidence indicates towards an association between SARS-CoV-2 infection and procoagulatory state in blood. Thromboelastographic investigations are useful point-of-care devices to assess coagulation and fibrinolysis. Objectives: We investigated the hypothesis that the procoagulatory state in COVID-19 patients is caused by impaired fibrinolysis system. Methods: COVID-19 patients admitted to normal wards or to the intensive care unit (ICU) were included in the study. Whole blood samples were investigated by thromboelastography. Additionally, global parameters of coagulation and factors of fibrinolysis as plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA), plasminogen activity and alpha 2-antiplasmin (A2AP) were determined. Results and conclusion: A significantly increased lysis-resistance and a significantly longer time of lysis after adding tissue plasminogen activator was observed in blood samples from ICU COVID-19 patients compared to controls (maximal lysis: 3.25% ± 0.56 vs. 6.20% ± 0.89, p=0.0127; lysis time: 365.7s ± 44.6 vs. 193.2s ± 16.3, p=0.0014). PAI-1 activity was significantly higher in plasma samples of ICU COVID-19 patients (PAI-1: 4.92U/ml ± 0.91 vs. 1.28U/ml ± 0.33, p=0.001). Interestingly, a positively correlation between the activity of PAI-1 and the lysis time of the formed clot (r=0.7015, p=0.0006) was observed. Our data suggest that severe SARS-CoV-2 infection is associated with impaired fibrinolytic activity in blood, where fibrinolytic inhibitors are elevated leading to an increased resistance to clot lysis. Future clinical studies should address the contribution of the fibrinolysis system to the procoagulatory state in blood of COVID-19 patients and investigate potential therapeutic targets in this system.

Coagulation and Fibrinolytic Activity in Behçet's Disease

1991 ◽  
Vol 66 (03) ◽  
pp. 292-294 ◽  
Author(s):  
K K Hampton ◽  
M A Chamberlain ◽  
D K Menon ◽  
J A Davies
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Behçet’S Disease ◽  
Fibrinolytic Activity ◽  
Behcet’S Disease ◽  
Behçet's Disease ◽  
Plasminogen Activator Inhibitor ◽  
Behcet's Disease ◽  
Tissue Plasminogen ◽  
Von Willebrand

SummaryCoagulation and fibrinolytic activities were studied in 18 subjects with Behçet's disease and compared with results from 14 matched control patients suffering from sero-negative arthritis. Significantly higher plasma concentrations (median and range) were found in Behçet's patients for the following variables: fibrinogen 3.7 (1.7-6.9) vs 3.0 (2.0-5.1) g/1, p <0.05; von Willebrand factor antigen, 115 (72-344) vs 74 (60-119)%, p <0.002; plasminogen activator activity (106/ECLT2) 219 (94-329) vs 137 (78-197) units, p <0.002; tissue plasminogen activator inhibitor (t-PA-I) activity, 9.1 (5.5-19.3) vs 5.1 (1.8-12.0) IU/ml, p <0.002; and PAI-1 antigen, 13.9 (4.5-20.9) vs 6.4 (2.4-11.1) ng/ml, p <0.002. Protein C antigen was significantly lower: 97 (70-183) vs 126 (96-220)%, p <0.02. No differences were observed in antithrombin III activity or antigen, factor VIII coagulant activity, fibrinopeptides A and Bβ15-42, plasminogen, α-2-antiplasmin, functional and immunological tissue-plasminogen activator, thrombin-antithrombin complexes and D-dimer. Levels of tissue plasminogen activator inhibitor (activity and antigen) correlated with disease activity while fibrinogen and von Willebrand factor concentrations did not. Seven of the 18 subjects with Behçet's disease had suffered thrombotic events but it was not possible to distinguish these from the 11 patients without thrombosis using the assays performed. The results suggest the abnormal fibrinolytic activity in Behçet's disease is due to increased inhibition of tissue plasminogen activator. No abnormality of coagulation or fibrinolytic activity specific to Behçet's disease was detected.

Relationships between Euglobulin Clot Lysis Time and the Plasma Levels of Tissue Plasminogen Activator and Plasminogen Activator Inhibitor 1

1990 ◽  
Vol 63 (01) ◽  
pp. 082-086 ◽  
Author(s):  
Tetsumei Urano ◽  
Kenji Sakakibara ◽  
Andrzej Rydzewski ◽  
Shoko Urano ◽  
Yumiko Takada ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Slight Modification ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Lysis Time ◽  
Tissue Plasminogen ◽  
Euglobulin Clot Lysis Time ◽  
Pai 1 ◽  
Clot Lysis Time

SummaryThe relationships between tissue plasminogen activator (tPA), its fast acting inhibitor (PAI-1) and euglobulin clot lysis time (ELT) were investigated with healthy volunteers’ plasma. Turbidimetric clot lysis assay by the microtiter plate reader was utilized for ELT with a slight modification. Both tPA and PAI-1 showed the significant correlation with ELT. tPA had a significantly positive, not negative, correlation with ELT (R = 0.387, p <0.001). Higher correlation coefficients (R = 0.580, p <0.001 and R = 0.599, p <0.001) were obtained between ELT and total PAI-1 or free PAI-1 than tPA or tPA-PAI-1 complex (R = 0.427, p <0.001). The positive correlation was also obtained between tPA and PAI-1. These data suggest that PAI-1 is a highly important factor for ELT, especially, the amounts of free PAI-1 being the key factor to determine the ELT, which can represent the potential activity of the fibrinolytic system.

scholarly journals Preparation of Peptide and Recombinant Tissue Plasminogen Activator Conjugated Poly(Lactic-Co-Glycolic Acid) (PLGA) Magnetic Nanoparticles for Dual Targeted Thrombolytic Therapy

2020 ◽  
Vol 21 (8) ◽  
pp. 2690 ◽  
Author(s):  
Huai-An Chen ◽  
Yunn-Hwa Ma ◽  
Tzu-Yuan Hsu ◽  
Jyh-Ping Chen
Keyword(s):  
Magnetic Nanoparticles ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Glycolic Acid ◽  
Blood Clot ◽  
Recombinant Tissue Plasminogen Activator ◽  
Clot Lysis ◽  
High Dose ◽  
Tissue Plasminogen

Recombinant tissue plasminogen activator (rtPA) is the only thrombolytic agent that has been approved by the FDA for treatment of ischemic stroke. However, a high dose intravenous infusion is required to maintain effective drug concentration, owing to the short half-life of the thrombolytic drug, whereas a momentous limitation is the risk of bleeding. We envision a dual targeted strategy for rtPA delivery will be feasible to minimize the required dose of rtPA for treatment. For this purpose, rtPA and fibrin-avid peptide were co-immobilized to poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (PMNP) to prepare peptide/rtPA conjugated PMNPs (pPMNP-rtPA). During preparation, PMNP was first surface modified with avidin, which could interact with biotin. This is followed by binding PMNP-avidin with biotin-PEG-rtPA (or biotin-PEG-peptide), which was prepared beforehand by binding rtPA (or peptide) to biotin-PEG-maleimide while using click chemistry between maleimide and the single –SH group in rtPA (or peptide). The physicochemical property characterization indicated the successful preparation of the magnetic nanoparticles with full retention of rtPA fibrinolysis activity, while biological response studies underlined the high biocompatibility of all magnetic nanoparticles from cytotoxicity and hemolysis assays in vitro. The magnetic guidance and fibrin binding effects were also confirmed, which led to a higher thrombolysis rate in vitro using PMNP-rtPA or pPMNP-rtPA when compared to free rtPA after static or dynamic incubation with blood clots. Using pressure-dependent clot lysis model in a flow system, dual targeted pPMNP-rtPA could reduce the clot lysis time for reperfusion by 40% when compared to free rtPA at the same drug dosage. From in vivo targeted thrombolysis in a rat embolic model, pPMNP-rtPA was used at 20% of free rtPA dosage to restore the iliac blood flow in vascular thrombus that was created by injecting a blood clot to the hind limb area.

ENDOTOXIN INDUCES DIC BY BOTH TISSUE FACTOR (TF) AND PLASMINOGEN ACTIVATOR-INHIBITOR (PA-l) SECRETION

1987 ◽  
Author(s):  
B Baldus ◽  
G Gehrmann ◽  
W Witt ◽  
P Donner
Keyword(s):  
Fibrinolytic Activity ◽  
Blood Clot ◽  
Plasminogen Activator Inhibitor ◽  
Clot Lysis ◽  
E Coli ◽  
Microtiter Plates ◽  
Lysis Time ◽  
Male Wistar Rats ◽  
Baseline Values ◽  
Activator Inhibitor

DIC-induced organ failure represents a major pathomecha-nism in endotoxemia. To investigate which components of the haemostatic system may be disturbed during endotoxemia anaesthetized male Wistar rats were injected with E. coli endotoxin at dosages of 1 ng/kg to 100 pg/kg body mass. Citrated blood samples were investigated for fibrinolytic activity by a dilute blood clot-lysis time assay (DBC-LT), for PA-I activity by a new Tunctional assay using immobilized rt-PA on 96-well microtiter plates and for TF activity by measuring the rate of thrombin formation after stimulation with a 2000-fold diluted thrombo plastin reagent.Endotoxin induced a decrease in fibrinolytic activity measured as a prolongation of the DBC-LT at dosages from 75 ng/kg to 100 μg/kg. This effect appeared 2 h after the treatment with endotoxin and persisted for<3 h. In parallel, an increase (up to 7-fold compared to baseline values) in PA-I activity could be measured 2 h after endotoxin application. When the plasma samples were clotted either by kaolin-phospholipid reagent, thrombin or reptilase in the resulting serum PA-I activity was more than 50-fold versus baseline. TF activity generated after stimulation with diluted thromboplastin reagent increased to about 5-fold compared to baseline values. This effect was already significant 1 h after endotoxin injection.The results of this study indicate, that endotoxin induces a destruction of the balance of the haemostatic system by increasing coagulability via stimulation of TF activity and by decreasing fibrinolytic activity by secretion of PA-I. Furthermore the present data provide evidence for activation of a latent form of PA-I during the clotting process.

α2-Antiplasmin, Plasminogen Activator Inhibitor (PAI) and Dilute Blood Clot Lysis Time in Selected Disease States

1991 ◽  
Vol 66 (05) ◽  
pp. 586-591 ◽  
Author(s):  
Mircea Cucuianu ◽  
Oliver Knauer ◽  
Stefan Roman
Keyword(s):  
Plasminogen Activator ◽  
Factor Xiii ◽  
Blood Clot ◽  
Plasminogen Activator Inhibitor ◽  
Clot Lysis ◽  
Disease States ◽  
Lysis Time ◽  
Activator Inhibitor ◽  
Dilute Blood ◽  
Clot Lysis Time

SummaryThis paper is an attempt to assess the relevance of the inhibitors of fibrinolysis for clot lysis in selected disease states and to discuss the mechanisms leading to acquired abnormal levels of such inhibitors. When compared to 20 control subjects the 30 hypertriglyceridemic patients (14 with type IIb and 16 with type IV) displayed significantly (p <0.001) increased plasma plasminogen activator inhibitor (PAI) activity (221 ± 88% and 290 ± 104% respectively; mean ± SD), moderately (p <0.01) increased α2 antiplasmin (α2AP) level (112 ± 11% and 115 ± 16%) and accordingly an obviously prolonged dilute blood clot lysis time (DBCLT). Neither PAI activity and α2AP level nor DBCLT were significantly different from controls in the 10 patients with hyperlipoproteinemia type IIa. The 18 patients with severe hepatic cirrhosis had low α2AP level (59 ± 19.7%) and accelerated clot lysis, while mean PAI activity (160 ± 87%) was slightly (p <0.05) increased. In the 17 nephrotic patients α2AP was increased (115 ±12%) while PAI activity was similar to controls and DBCLT rather shorter. Two liver secretion enzymes, namely serum Cholinesterase and plasma protein C, were found to be decreased in cirrhotic patients, similar to control values in hyperlipoproteinemia type Ha and obviously increased in nephrotic patients as well as in hypertriglyceridemic subjects. The relevance of PAI and α2AP for clot lysis was considered in relation to data in the literature concerning the behaviour of t-PA and factor XIII. Enhanced hepatic synthesis of protease inhibitors and factor XIII as a possible cause of delayed clot lysis in hypertriglyceridemia was envisaged.

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