Studies on Activator Formation in Human Plasma with Streptokinase

1976 ◽  
Vol 36 (03) ◽  
pp. 566-581 ◽  
Author(s):  
M Martin ◽  
Miss H Auel ◽  
Keyword(s):  
Human Plasma ◽  
Strong Correlation ◽  
Clot Lysis ◽  
Activator Concentration ◽  
Nacl Solution ◽  
Lysis Time ◽  
Streptokinase Infusion ◽  
Activator Complex ◽  
Native Plasma ◽  
Clot Lysis Time

SummaryA new method is presented for estimating the activator (plasminogen-streptokinase complex) concentration in native plasma of patients undergoing streptokinase infusion. The principle of the method is based on clot lysis time as recorded by the thromboelastograph. The test clot constituents were bovine fibrinogen, bovine plasminogen, EDTA, human plasma (with unknown activator concentrations), and thrombin. In order to obtain a standardization line, urokinase dissolved in NaCl solution was substituted for patients’ plasma. Thus, each lysis time could easily be converted into urokinase equivalent (CTA-u/ml). Streptokinase and plasminogen molecules in undiluted patients’ plasma were found to exist both in an activator-bound (equimolar plasminogen-streptokinase complex) and in a freely circulating form. This result is in agreement with earlier findings where the activator complex was demonstrated to be a widely dissociated complex in highly diluted plasma of patients, thus displaying an ample proportion of free streptokinase and plasminogen molecules. Streptokinase treatment using dosage schemes of 100,000 u SK/h, 150,000 u/h, and 200,000 u/h were monitored by quantitative activator, streptokinase, and plasminogen measurements. An average activator concentration of 50–100 CTA-u/ml and a SK-concentration of 7–16 u/ml were recorded during streptokinase infusion. Plasminogen values averaged 0.25%, independent of the amount of streptokinase infused. Each drop in streptokinase was accompanied by a drop in activator during the infusion, and each rise in streptokinase by a rise in activator. There was a strong correlation between streptokinase and activator concentrations in that, on the average, 1 u streptokinase equalled 8.4 CTA-u/ml activator (correlation coefficient r = 0.9). It is concluded that the activator concentration in the plasma of patients undergoing fibrinolytic treatment can easily be adjusted by regulating the hourly streptokinase influx.

Quantitative Activator Determination in the Plasma of Patients Undergoing Fibrinolytic Treatment

1975 ◽  
Author(s):  
M. Martin ◽  
H. Auel
Keyword(s):  
Human Plasma ◽  
Correlation Coefficient ◽  
Strong Correlation ◽  
New Method ◽  
Activator Concentration ◽  
Nacl Solution ◽  
Lysis Time ◽  
Streptokinase Infusion

A new method ist presented for estimating the activator (plasminogenstreptokinase complex) concentration in the plasma of patients undergoing streptokinase infusion. The principle of the method is based on the clotlysis time as recorded by the thromboelastograph. The test clot constituents were bovine fibrinogen, bovine plasminogen, EDTA, human plasma (with unknown activator concentrations) and thrombin. In order to obtain a standardization curve, urokinase dissolved in NaCl solution was substituted for patient’s plasma. Thus, each lysis time could easily be converted into urokinase equivalent (CTA u/ml). Streptokinase treatment using a dosage scheme of 100,000 u SK/h was monitored by quantitative activator, plasminogen, and streptokinase measurements. During streptokinase infusion an average activator concentration of 20–120 CTA u UK-equ and a SK-concentration of 3–8 u/ml were recorded. Each drop in streptokinase was accompanied by a drop in activator, and each rise in streptokinase by a rise in activator. There was a strong correlation between streptokinase and activator concentrations (correlation coefficient r = 0.9).

Distinction of Plasma Inhibitor of Activator-Induced Clot Lysis from Antiplasmins

1975 ◽  
Author(s):  
N. Aoki ◽  
M. Matsuda ◽  
M. Moroi ◽  
N. Yoshida
Keyword(s):  
Affinity Chromatography ◽  
Human Plasma ◽  
Gel Filtration ◽  
Plasminogen Activators ◽  
Inhibitory Effect ◽  
Clot Lysis ◽  
Plasminogen Activation ◽  
Lysis Time ◽  
Α2 Macroglobulin ◽  
Clot Lysis Time

A fraction of human plasma prolongs the activator-induced clot lysis time and inhibits plasminogen activation by the plasminogen activators derived from various sources (urine and tissues). This fraction, designated as antiactivator fraction, was separatid from antiplasmin fractions (α2-macroglobulin and α1-antitrypsin) by gel filtration and affinity chromatography on Sepharose coupled with IgG of antiserum to α1-antitrypsin. Anti-activator fraction thus obtained exerted little antiplasmin activity but inhibited strongly activator-induced clot lysis.Inhibitory effect of plasma on urokinase-induced clot lysis (antiactivator activity) was assayed in various diseases and compared with antiplasmin activity. No correlation was found between the two activities, and it was concluded that the two activities are independent and are ascribed to two different entities.

scholarly journals A Direct Oral Anticoagulant Edoxaban Enhanced Fibrinolysis Via Inhibition of Thrombin-Activatable Fibrinolysis Inhibitor Activation and Enhancement of Plasmin Generation in Human Plasma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3786-3786
Author(s):  
Yoshiyuki Morishima ◽  
Yuko Honda ◽  
Taketoshi Furugohri
Keyword(s):  
Human Plasma ◽  
Vitamin K Antagonists ◽  
Oral Anticoagulants ◽  
Clot Lysis ◽  
Thrombin Activatable Fibrinolysis Inhibitor ◽  
Normal Plasma ◽  
Lysis Time ◽  
Fibrinolysis Inhibitor ◽  
Maximum Turbidity ◽  
Clot Lysis Time

Abstract Introduction: Direct oral anticoagulants are as effective as vitamin K antagonists for the treatment of venous thromboembolism and are associated with less bleeding. We have reported that a direct oral factor Xa inhibitor edoxaban exerts a thrombus resolution effect in a rat model of venous thrombosis and enhances tissue plasminogen activator (t-PA)-induced clot lysis in human plasma. However, the mechanism underlying the thrombus resolution effect and fibrinolysis enhancement by edoxaban remains to be determined. Purposes: To evaluate the effect of edoxaban on plasmin generation during clot lysis in human plasma in vitro. To determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) in the enhancement of fibrinolysis by edoxaban. Methods: Pooled human normal plasma or TAFI-deficient plasma (both containing 180 ng/mL t-PA and 0.1 nM thrombomodulin) was mixed with edoxaban, an activated TAFI (TAFIa) inhibitor (a fibrinolysis enhancer) potato tuber carboxypeptidase inhibitor (PCI), or vehicle. Clot was induced by adding 2.5 pM tissue factor and 4 µM phospholipids. To monitor the clot formation and lysis, the absorbance of plasma at 405 nm was measured every 30 sec. Clot lysis time was defined as the interval between the time of the midpoint of the clear to maximum turbidity transition and the midpoint of the maximum turbidity to clear transition. Plasmin-α2 antiplasmin complex (PAP) concentration was measured by ELISA as an indicator of plasmin generation. Results: In normal plasma, PCI accelerated clot lysis and increased plasma PAP concentration. There was a correlation between plasma PAP concentration and percent of clot lysis, indicating that plasma PAP concentration is an appropriate marker of fibrinolysis. Edoxaban at clinically relevant concentrations (75, 150, and 300 ng/mL) significantly shortened clot lysis time and elevated plasma PAP concentration. The additive combined effect of edoxaban and PCI was observed. In TAFI-deficient plasma, clot lysis time was shortened and plasma PAP concentration increased compared with normal plasma. In these samples, the effects of edoxaban and PCI on clot lysis and plasma PAP concentration were markedly diminished as compared with normal plasma. Conclusions: Edoxaban at clinically relevant concentrations enhanced t-PA-induced clot lysis with increasing plasma PAP concentration in human plasma. The effects of edoxaban on clot lysis and plasmin generation were diminished in TAFI-deficient plasma. A TAFIa inhibitor PCI exerted similar effects. These data suggest that edoxaban enhanced fibrinolysis via inhibition of TAFI activation and enhancement of plasmin generation. Disclosures Morishima: Daiichi Sankyo Co., Ltd.: Employment. Honda:Daiichi Sankyo Co., Ltd.: Employment. Furugohri:Daiichi Sankyo Co., Ltd.: Employment.

Indirect Measurement of Streptokinase Concentration in the Plasma of Patients Undergoing Fibrinolytic Treatment

1974 ◽  
Vol 32 (02/03) ◽  
pp. 633-650 ◽  
Author(s):  
M Martin
Keyword(s):  
Human Plasma ◽  
Coagulation Factors ◽  
Indirect Measurement ◽  
Clot Lysis ◽  
Metabolism Rate ◽  
Lysis Time ◽  
Quantitative Basis ◽  
Streptokinase Infusion ◽  
High Concentrations

SummaryA new method of determining streptokinase concentrations on a quantitative basis in the plasma of patients undergoing streptokinase infusion is demonstrated. The principle of this method is based on the clot lysis time recorded by the thrombo-elastograph. The test clot constituents were bovine fibrin, bovine plasminogen, human euglobulin, EDTA, human plasma (with unknown streptokinase quantity) and thrombin. As plasminogen (euglobulin) and fibrinogen were present in the test coagulum in rather high concentrations (fixed excess) no interference with changing plasminogen and fibrinogen levels of the patient’s plasma was observed. Further, due to high EDTA concentrations, no interaction with platelet functions and coagulation factors took place. The standard error of measuring 5 u of streptokinase in one ml of human plasma was determined at s = ±0.47 u/ml.Eleven patients undergoing fibrinolytic treatment with streptokinase were monitored by streptokinase determination in the plasma. In this group of patients, streptokinase concentration values varying between 15 and 0.5 units/ml plasma were measured. One striking feature was the continuous decrease in streptokinase concentration in the plasma, in spite of unchanged streptokinase infusion rates. This observation was consistent in regimens with both large (100,000 u/h) and small (30,000 u/h) streptokinase infusion rates. No explanation is available for this observation up to now. A rise in circulating anti-streptokinase contents was precluded. Possibly, an accelerated streptokinase metabolism rate in the course of long-term streptokinase administration may be involved.

Thrombomodulin in Human Plasma Contributes to Inhibit Fibrinolysis through Acceleration of Thrombin-dependent Activation of Plasma Procarboxypeptidase B

1998 ◽  
Vol 79 (02) ◽  
pp. 371-377 ◽  
Author(s):  
Yoshitaka Hosaka ◽  
Yasuo Takahashi ◽  
Hidemi Ishii
Keyword(s):  
Human Plasma ◽  
Clot Lysis ◽  
Direct Inhibition ◽  
Carboxypeptidase B ◽  
Lysis Time ◽  
Tissue Plasminogen ◽  
Dependent Inhibition ◽  
Normal Human ◽  
Clot Lysis Time

SummaryThrombomodulin (TM) expressed on endothelial cells binds thrombin and initiates anticoagulant pathways. Soluble functional proteolytic fragments of TM are also present in circulating plasma. Recently, it was reported that TM accelerated thrombin-dependent plasma procarboxypeptidase B (pro-pCPB) activation in a purified system and suggested that TM may inhibit fibrinolysis in crude plasma. The aim of present study was to evaluate any functional role of soluble TM fragments in plasma or purified TM added into plasma to the regulation of coagulation and fibrinolysis. Addition of rabbit TM (1-200 ng/ml) to plasma resulted in a concentration-dependent prolongation of urokinase (UK)- or tissue plasminogen activator (t-PA)-induced clot lysis time. The concentration of TM required for the inhibition of fibrinolysis was lower than that required for the inhibition of coagulation. Addition of anti-rabbit TM IgG or anti-human TM IgG into plasma reduced UK- or t-PA-induced clot lysis time without affecting clotting times, indicating that exogenous TM or soluble TM fragments in normal human plasma participated in regulation of fibrinolysis. Moreover, the TM-dependent inhibition of fibrinolysis was observed only in the presence of thrombin and blocked by addition of carboxypeptidase B inhibitors, but not mediated by protein C activation or direct inhibition of UK, t-PA or plasmin. Analysis of various substrates and inhibitors indicated that TM accelerated thrombin-dependent pro-pCPB activation in plasma. The present results indicate that TM, including soluble TM fragments in plasma, inhibit fibrinolysis via activation of pro-pCPB in plasma.

Different mechanisms contribute to the biphasic pattern of carboxypeptidase U (TAFIa) generation during in vitro clot lysis in human plasma

2003 ◽  
Vol 89 (02) ◽  
pp. 264-271 ◽  
Author(s):  
Judith Leurs ◽  
Britt-Marie Wissing ◽  
Viveca Nerme ◽  
Katinka Schatteman ◽  
Petter Björquist ◽  
...  
Keyword(s):  
Human Plasma ◽  
Time Course ◽  
Thrombin Inhibitor ◽  
Clot Lysis ◽  
Time Period ◽  
Lysis Time ◽  
Two Peaks ◽  
Plasmin Inhibitor ◽  
Clot Lysis Time

SummaryCarboxypeptidase U (CPU, TAFIa) recently gained interest as a significant player in dampening the fibrinolytic rate. The aim of this study was to investigate the time course of the generation of CPU activity during coagulation and fibrinolysis using an in vitro clot lysis model in human plasma. A first peak of CPU activity appeared after initiation of the coagulation phase and a second rise in CPU activity was observed during the fibrinolysis. The decrease in the proCPU plasma concentration followed the same trend as the appearance of the CPU activity. The direct thrombin inhibitor inogatran eliminated the CPU generation during coagulation but not during fibrinolysis. Addition of the plasmin inhibitor aprotinin during fibrinolysis resulted in a decrease in CPU activation during the lysis phase. These results demonstrate that proCPU was activated during coagulation by thrombin and during fibrinolysis by plasmin. Addition of a CPU inhibitor before initiation of clotting decreased the clot lysis time as expected. However, addition in the time period between the two peaks of CPU activity had no apparent effect on the clot lysis time.

Influence of Moderate and Strenuous Daily Physical Activity on Fibrinolytic Activity of Blood: Possibility of Plasminogen Activator Stores Depletion

1979 ◽  
Vol 41 (04) ◽  
pp. 745-755 ◽  
Author(s):  
Dušan Keber ◽  
Mojca Stegnar ◽  
Irena Keber ◽  
Bojan Accetto
Keyword(s):  
Physical Activity ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Regular Physical Activity ◽  
Clot Lysis ◽  
Moderate Activity ◽  
Lysis Time ◽  
Strenuous Activity ◽  
Activity Measurements ◽  
Clot Lysis Time

SummaryFibrinolysis was studied in 10 alpinists during regular physical activity of different intensity. Blood was sampled at rest and after exposure to submaximal workload on the treadmill on three occasions: before and after 6 months physical conditioning (moderate physical activity), and after 6 weeks of an alpinistic expedition (strenuous physical activity). Measurements included submaximal working capacity, fibrinogen, euglobulin clot lysis time (ELT), whole plasma clot lysis time, and estimations derived from ELT - percent increase in fibrinolytic activity after exercise (RFS), and absolute increase in fibrinolytic activity after exercise (PAR).Regular moderate activity increased the resting level of ELT, but strenuous activity decreased is. After each treadmill testing, a marked increase in fibrinolytic activity was observed. RFS was unaltered at all three testings. PAR increased after moderate activity, but decreased after strenuous activity.The results indicate that regular physical activity can lead from enhanced to decreased resting activity of plasminogen activator in blood. It is presumed that increased release of activator during prolonged stress causes partial depletion of endothelial stores with the consequence of decreased activator activity in the blood.

The Effect of Copper Ions on Clot Lysis Time in the Fibrinolytic Assay of Streptokinase

1965 ◽  
Vol 13 (02) ◽  
pp. 477-483
Author(s):  
Alwin B. Bogert
Keyword(s):  
Copper Ions ◽  
Borate Buffer ◽  
Fibrinolytic System ◽  
Clot Lysis ◽  
Distilled Water ◽  
Naturally Occurring ◽  
Lysis Time ◽  
Low Levels ◽  
Effect Of Copper ◽  
Clot Lysis Time

SummaryExperiments were conducted to determine why different lots of Borate Buffer reagent affect the clot lysis times obtained in the fibrinolytic assay of Streptokinase. Minerals naturally occurring in distilled water were screened individually to determine their influence on lysis. Copper was found to have a very pronounced effect in this regard on the fibrinolytic system in that low levels reduce the lysis time and high levels increase it.

Altered fibrin clot structure/function in patients with antiphospholipid syndrome: association with thrombotic manifestation

2014 ◽  
Vol 112 (08) ◽  
pp. 287-296 ◽  
Author(s):  
Magdalena Celińska-Löwenhoff ◽  
Teresa Iwaniec ◽  
Agnieszka Padjas ◽  
Jacek Musiał ◽  
Anetta Undas
Keyword(s):  
Structure Function ◽  
Antiphospholipid Syndrome ◽  
Thrombotic Event ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Lag Phase ◽  
Lysis Time ◽  
Clot Structure ◽  
Clot Lysis Time ◽  
D Dimer

SummaryWe tested the hypothesis that plasma fibrin clot structure/function is unfavourably altered in patients with antiphospholipid syndrome (APS). Ex vivo plasma clot permeability, turbidity and susceptibility to lysis were determined in 126 consecutive patients with APS enrolled five months or more since thrombotic event vs 105 controls. Patients with both primary and secondary APS were characterised by 11% lower clot permeability (p<0.001), 4.8% shorter lag phase (p<0.001), 10% longer clot lysis time (p<0.001), and 4.7% higher maximum level of D-dimer released from clots (p=0.02) as compared to the controls. Scanning electron microscopy images confirmed denser fibrin networks composed of thinner fibres in APS. Clots from patients with “triple-antibody positivity” were formed after shorter lag phase (p=0.019) and were lysed at a slower rate (p=0.004) than in the remainder. Clots from APS patients who experienced stroke and/or myocardial infarction were 8% less permeable (p=0.01) and susceptible to lysis (10.4% longer clot lysis time [p=0.006] and 4.5% slower release of D-dimer from clots [p=0.01]) compared with those following venous thromboembolism alone. Multivariate analysis adjusted for potential confounders showed that in APS patients, lupus anticoagulant and “triple-positivity” were the independent predictors of clot permeability, while “triple-positivity” predicted lysis time. We conclude that APS is associated with prothrombotic plasma fibrin clot phenotype, with more pronounced abnormalities in arterial thrombosis. Molecular background for this novel prothrombotic mechanism in APS remains to be established.

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