Changes in Clotting and Fibrinolytic Parameters Produced by Venous Stasis

1996 ◽  
Vol 2 (1) ◽  
pp. 64-68
Author(s):  
Raul Altman ◽  
Alejandra Scazziota ◽  
Jorge Rouvier
Keyword(s):  
Sodium Citrate ◽  
Vascular Endothelial Cells ◽  
Protein S ◽  
Venous Occlusion ◽  
Venous Stasis ◽  
Clot Lysis ◽  
Before And After ◽  
Fibrinolytic Parameters ◽  
Pai 1

Vascular endothelial cells have thrombosis- prevention properties through the release of some fibri nolytic factors. This capacity of endothelium was studied using the venous occlusion test (VOT) and measuring proteins released during stasis. Blood samples were col lected before and after 10 and 20 min VOT in tubes con taining sodium citrate at pH 7.0 or 4.3. A significant shortening of the euglobulin clot lysis time (ECLT) was obtained 10 and 20 min after VOT in plasma collected in citrate pH 7.0 or 4.3. No statistical difference was noted between results obtained 10 and 20 minutes after VOT. The shortening was related to the increase of tissue plas minogen activator (t-PA) released during VOT. No differ ence was detected in the concentration of tissue plasmin ogen activator inhibitor 1 (PAI-1), but PAI-1 activity mea sured in plasma from blood collected in citrate pH 7.0 decreased progressively from 10.8 ± 9.2 arbitrary units (AU)/ml to 3.76 ± 4.5 AU/ml and 0.8 ± 1.02 AU/ml (p < 0.001) after 10 and 20 min, respectively, of stasis. When the PAI-1 activity was determined in blood collected in citrate pH 4.3 for preventing in vitro complexing of PAI-1 and t-PA, results were different: PAI-1 activity decreased from a basal value of 29.2 ± 15.3 AU/ml to 24.9 ± 12.2 ( p = NS) and 18.7 ± 11.5; p < 0.02) 10 and 20 min after VOT. As result of fibrinolytic activation, other factors were modified: increase of plasminogen activators, de crease of plasminogen, and increase of D-dimer. Fibrin ogen, fibronectin, protein C, protein S, von Willebrand factor, and tissue factor pathway inhibitor concentration remained unchanged after VOT. According to our find ings, VOT can be performed with a stasis of 10 min. Good responders are related to the endothelial capacity for re leasing t-PA and urokinase-type PA (u-PA) and defined as those with an ECLT of <60 min after 10 min VOT when blood was collected in sodium citrate pH 7.0.

Activated Protein C Increases Fibrin Clot Lysis by Neutralization of Plasminogen Activator Inhibitor No Evidence for a Cofactor Role of Protein S

1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina
Keyword(s):  
Plasminogen Activator ◽  
Protein C ◽  
Blood Platelets ◽  
Plasminogen Activator Inhibitor ◽  
Protein S ◽  
Tissue Type ◽  
Clot Lysis ◽  
Activator Inhibitor ◽  
Pai 1

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.

A Plasma Clot Lysis Assay Based on the Release of Fibrin Degradation Products: Application to the Diagnosis of Hypofibrinolytic States

1990 ◽  
Vol 63 (01) ◽  
pp. 076-081 ◽  
Author(s):  
Pascale Gaussem ◽  
Sophie Gandrille ◽  
Pascale Molho-Sabatier ◽  
Loïc Capron ◽  
Jean-Noël Fiessinger ◽  
...  
Keyword(s):  
Degradation Products ◽  
Venous Occlusion ◽  
Lower Limbs ◽  
Clot Lysis ◽  
Plasma Clot ◽  
Vein Thrombosis ◽  
Fibrin Degradation Products ◽  
Before And After ◽  
Euglobulin Clot Lysis Time ◽  
Pai 1

SummaryUsing a monoclonal antibody-based assay, we measured the fibrin degradation product release in the supernatant of plasma clots obtained before and after venous occlusion (VO) in 30 patients with definite or suspected vascular thrombosis (19 definite and 2 suspected deep vein thrombosis, 6 recurrent superficial thrombophlebitis, 3 arterial occlusions of lower limbs). tPA and PAI-1 concentrations were determined using ELISA assays; the post-occlusion values were corrected for haemoconcentration. The increase in tPA during VO was correlated with haemoconcentration (r = 0.74), but 3 patients had ineffective VO (<2% increase in proteins). The fibrinolytic response to VO was evaluated using the shortening of the time necessary for the release of 200 μg of fibrin degradation products per mg of fibrinogen (Δ T 200). Two among the 27 patients with effective VO were bad responders with a Δ T 200 <3 h (whereas all the others had Δ T 200 >10 h). These patients had respectively a deficient tPA release (Δ tPA = 1 ng/ml) and an elevated PAI-1 level at rest (33 ng/ml). Several other patients were bad responders in terms of tPA release or of shortening of the euglobulin clot lysis time but they had a normal Δ T 200. This plasma clot test reflects the ability of free tPA to bind to fibrin (the amount of which depends on the level of tPA and PAI-1), and may be useful in the diagnosis of a hypofibrinolytic state.

The Inhibitory Effect of Aspirin on Fibrinolysis Is Reversed by Iloprost, a Prostacyclin Analogue

1989 ◽  
Vol 61 (02) ◽  
pp. 286-288 ◽  
Author(s):  
V Bertelé ◽  
L Mussoni ◽  
G Pintucci ◽  
G del Rosso ◽  
G Romano ◽  
...  
Keyword(s):  
Fibrinolytic Activity ◽  
Specific Inhibitor ◽  
Venous Occlusion ◽  
Inhibitory Effect ◽  
Venous Stasis ◽  
Prostacyclin Analogue ◽  
Fibrin Plate ◽  
Before And After ◽  
Prostacyclin Production ◽  
Pai 1

SummaryThe reduced fibrinolytic response after aspirin intake may be due to prevention of prostacyclin production. The effect of iloprost (a stable prostacyclin analogue) was tested on the fibrinolytic activity (euglobulin lysis area on fibrin plate [E.L.A.], t-PA antigen, PAI activity and PAI-1 antigen) of plasma drawn after venous stasis test from six healthy male volunteers, who each received all the following treatments according to a single-blind randomized cross-over design: placebo, iloprost, aspirin + placebo, aspirin + iloprost. The mean E. L. A. value after venous occlusion was significantly higher than the basal level after every treatment, but aspirin. Within each treatment group the t-PA antigen levels in response to venous stasis were significantly higher than the basal ones. PAI-1 antigen levels did not change significantly before and after venous stasis either within or among the treatment groups. These data are consistent with the hypothesis that the mechanism related to aspirin’s effect on fibrinolysis is mediated by suppression of vessel wall prostacyclin production. Aspirin’s inhibitory effect on fibrinolysis was in fact prevented by replacing endogenous prostacyclin with iloprost. Iloprost enhances fibrinolytic activity reduced by aspirin, but not by promoting t-PA release or by inhibiting release of the specific inhibitor, PAI-1.

FIBRINOLYTIC RESPONSE AFTER VENOUS OCCLUSION AND DDAVP IN PATIENTS WITH DEEP VENOUS THROMBOSIS

1987 ◽  
Author(s):  
M Kozak ◽  
D Keber
Keyword(s):  
Hydrostatic Pressure ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Venous Occlusion ◽  
Venous Stasis ◽  
Clot Lysis ◽  
Postthrombotic Syndrome ◽  
Before And After ◽  
The Difference ◽  
Fibrinolytic Potential

After prolonged stimulation venous endothelium becomes refractory to otherwise efficacious stimuli for tissue plasminogen activator (t-PA) release. When the stimulus is removed, the restitution of the response is observed. The distention of the veins distally from the occlusion site in deep venous thrombosis (DVT) could represent such a chronic stimulus. We studied t-PA release in patients with DVT during 20-min venous occlusion (VO) and DDAVP infusion (0,4 ug/kg b.w. in 10 min). t-PA release was estimated as the difference in euglobulin clot lysis time (ECLT in U) and fibrin plates (FP in mm2) before and after VO (fibrinolytic potential). Two groups of patients were studied: 15 recumbent patients with oneside iliofemoral DVT, and 15 patients with oneside postthrombotic syndrome.In both groups the response of legs was lower than that of arms. The comparison of the healthy and the affected leg in postthrombotic group showed no difference in t-PA release after VO. A higher release of t-PA was seen in the acute DVT group in all three tested limbs, explainable by a restitution of fibrinolytic potential due to the reduction of hydrostatic stimulus. However, the response was slightly lower in the diseased leg. In 5 patients from the acute DVT group DDAVP infusion induced higher t-PA release after VO in both legs compared to VO before DDAVP. We can conclude that hydrostatic pressure in upright position is such a strong stimulus that an additional decrease of t-PA release due to chronic venous stasis cannot be expressed. In recumbent patients DVT hinders the restitution of the response to V0 in the diseased leg. DDAVP seems to act independently of hydrostatic pressure and venous stasis.

Fibrinolysis in Normal Subjects - Comparison Between Plasminogen Activator Inhibitor and Other Components of the Fibrinolytic System

1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Plasminogen Activator Inhibitor ◽  
Venous Occlusion ◽  
Venous Stasis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Plate Assay ◽  
Fibrin Plate ◽  
Activator Inhibitor ◽  
Pai 1

SummaryWe analyzed fibrinolytic parameters in 20 healthy men and 20 healthy women, aged from 25 to 59, before and after 10 and 20 min venous occlusion. The 10 min post-occlusion fibrinolytic activity measured directly in diluted unfractionated plasma by a highly sensitive 125I-fibrin plate assay correlated well with the activity of euglobulins determined by the classical fibrin plate assay (r = 0.729), but pre-stasis activities determined with these two methods did not correlate (r = 0.084). The enhancement of fibrinolytic activity after venous occlusion was mainly due to an increase of t-PA in the occluded vessels (4-fold increase t-PA antigen after 10 min and 8-fold after 20 min venous occlusion). Plasminogen activator inhibitor (PAI) activity and plasminogen activator inhibitor 1 (PAI-1)1 antigen levels at rest showed considerable dispersion ranging from 1.9 to 12.4 U/ml, respectively 6.9 to 77 ng/ml. A significant increase of PAI-1 antigen levels was observed after 10 and 20 min venous occlusion. At rest no correlation was found between PAI activity or PAI-1 antigen levels and the fibrinolytic activity measured by 125I-FPA. However, a high level of PAI-1 at rest was associated with a high prestasis antigen level of t-PA and a low fibrinolytic response after 10 min of venous stasis. Since the fibrinolytic response inversely correlated with PAI activity at rest, we conclude that its degree depends mainly on the presence of free PAI.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

The Roles of α2-Antiplasmin and Plasminogen Activator Inhibitor 1 (PAI-1) in the Inhibition of Clot Lysis

1993 ◽  
Vol 70 (02) ◽  
pp. 301-306 ◽  
Author(s):  
Linda A Robbie ◽  
Nuala A Booth ◽  
Alison M Croll ◽  
Bruce Bennett
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Dependent Inhibition ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe relative importance of the two major inhibitors of fibrinolysis, α2-antiplasmin (α2-AP) and plasminogen activator inhibitor (PAI-1), were investigated using a simple microtitre plate system to study fibrin clot lysis in vitro. Cross-linked fibrin clots contained plasminogen and tissue plasminogen activator (t-PA) at concentrations close to physiological. Purified α2-AP and PAI-1 caused dose-dependent inhibition. All the inhibition due to normal plasma, either platelet-rich or poor, was neutralised only by antibodies to α2-AP. Isolated platelets, at a final concentration similar to that in blood, 2.5 × 108/ml, markedly inhibited clot lysis. This inhibition was neutralised only by antibodies to PAI-1. At the normal circulating ratio of plasma to platelets, α2-AP was the dominant inhibitor. When the platelet:plasma ratio was raised some 20-fold, platelet PAI-1 provided a significant contribution. High local concentrations of PAI-1 do occur in thrombi in vivo, indicating a role for PAI-1, complementary to that of α2-AP, in such situations.

In Vitro Clot Lysis as a Potential Indicator of Thrombus Resistance to Fibrinolysis – Study in Healthy Subjects and Correlation with Blood Fibrinolytic Parameters

1997 ◽  
Vol 77 (04) ◽  
pp. 725-729 ◽  
Author(s):  
Mario Colucci ◽  
Silvia Scopece ◽  
Antonio V Gelato ◽  
Donato Dimonte ◽  
Nicola Semeraro
Keyword(s):  
Plasminogen Activator ◽  
Clot Lysis ◽  
Individual Response ◽  
Plasminogen Activator Inhibitor 1 ◽  
Autologous Plasma ◽  
Wide Range ◽  
Blood Clots ◽  
Physiological Variations ◽  
Pai 1

SummaryUsing an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37° C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-anti-plasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p <0.001) and age (p <0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-ginduced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy.

scholarly journals Granulocyte microvesicles with a high plasmin generation capacity promote clot lysis and improve outcome in septic shock

Blood ◽  
2022 ◽  
Author(s):  
Sylvie Cointe ◽  
Loris Vallier ◽  
Pierre Esnault ◽  
Mathilde Dacos ◽  
Amandine Bonifay ◽  
...  
Keyword(s):  
Septic Shock ◽  
Murine Model ◽  
Thrombus Formation ◽  
Protective Role ◽  
Clot Lysis ◽  
Dependent Manner ◽  
Kinetic Assay ◽  
Generation Capacity ◽  
Pai 1

Microvesicles (MVs) have previously been shown to exert profibrinolytic capacity, which is increased in patients with septic shock (SS) with a favorable outcome. We therefore hypothesized that the plasmin generation capacity (PGC) could confer to MVs a protective effect supported by their capacity to lyse a thrombus, and we investigated the mechanisms involved. Using a MV-PGC kinetic assay, ELISA and flow cytometry, we found that granulocyte MVs (Gran-MVs) from SS patients display a heterogeneous PGC profile driven by the uPA (urokinase)/uPAR system. In vitro, these MVs lyse a thrombus according to their MV-PGC levels in a uPA/uPAR-dependent manner, as shown in a fluorescent clot lysis test and a lysis front retraction assay. Fibrinolytic activators conveyed by MVs contribute to approximately 30% of the plasma plasminogenolytic capacity of SS patients. In a murine model of SS, the injection of high PGC Gran-MVs significantly improved mouse survival and reduced the number of thrombi in vital organs. This was associated with a modification of the mouse coagulation and fibrinolysis properties toward a more fibrinolytic profile. Interestingly, mouse survival was not improved when soluble uPA was injected. Finally, using a multiplex array on plasma from SS patients, we found that neutrophil elastase correlates with the effect of high-PGC-capacity plasma and modulates the Gran-MV plasmin generation capacity by cleaving uPA-PAI-1 complexes. In conclusion, we show that high PGC level displayed by Gran-MVs reduce thrombus formation and improve survival conferring to Gran-MVs a protective role in a murine model of sepsis.

scholarly journals Inhibition of clot lysis and decreased binding of tissue-type plasminogen activator as a consequence of clot retraction

Blood ◽  
1992 ◽  
Vol 79 (6) ◽  
pp. 1420-1427 ◽  
Author(s):  
S Kunitada ◽  
GA FitzGerald ◽  
DJ Fitzgerald
Keyword(s):  
Plasminogen Activator ◽  
Tissue Type ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Clot Retraction ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Pai 1

Tissue-type plasminogen activator (t-PA) is less active in vivo and in vitro against clots that are enriched in platelets, even at therapeutic concentrations. The release of radioactivity from 125I-fibrin-labeled clots was decreased by 47% 6 hours after the addition of t-PA 400 U/mL when formed in platelet-rich versus platelet-poor plasma. This difference was not due to the release of plasminogen activator inhibitor-1 (PAI-1) by platelets. Thus, the fibrinolytic activity of t- PA in the supernatant was similar in the two preparations and fibrin autography demonstrated only a minor degree of t-PA-PAI-1 complex formation. Furthermore, a similar platelet-dependent reduction in clot lysis was seen with a t-PA mutant resistant to inhibition by PAI-1. The reduction in t-PA activity correlated with a decrease in t-PA binding to platelet-enriched clot (60% +/- 3% v platelet-poor clot, n = 5). This reduction in binding was also shown using t-PA treated with the chloromethylketone, D-Phe-Pro-Arg-CH2Cl (PPACK) (36% +/- 13%, n = 3), and with S478A, a mutant t-PA in which the active site serine at position 478 has been substituted by alanine (43% +/- 6%, n = 3). In contrast, fixed platelets and platelet supernatants had no effect on the binding or lytic activity of t-PA. Pretreatment with cytochalasin D 1 mumol/L, which inhibits clot retraction, also abolished the platelet- induced inhibition of lysis and t-PA binding by platelets. These data suggest that platelets inhibit clot lysis at therapeutic concentrations of t-PA as a consequence of clot retraction and decreased access of fibrinolytic proteins.

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