Interaction of Heparin with Fibrinolysis

1963 ◽  
Vol 09 (02) ◽  
pp. 446-458 ◽  
Author(s):  
Rudolf Holemans ◽  
Dionysios Adamis ◽  
James F Horace
Keyword(s):  
Human Plasma ◽  
Fibrinolytic Activity ◽  
Plasminogen Activation ◽  
Fibrinolytic Agents ◽  
High Concentration ◽  
Enhancing Effect

SummaryHeparin in high concentration inhibits the fibrinolysis of human plasma clots or bovine fibrin by fibrinolytic agents which produce plasminogen activation. Heparin has no effect on the fibrinolytic activity of plasmin or Aspergillus protease.In order to produce inhibition of plasminogen activation heparin requires the presence of a co-factor which is present in citrated human plasma but absent from its euglobulin fraction.In none of the concentrations tested has heparin an enhancing effect on fibrinolysis.

The Effects of Sodium Citrate and an Excess of Plasminogen on Fibrinolytic Agents

1960 ◽  
Vol 04 (03) ◽  
pp. 462-472 ◽  
Author(s):  
Tage Astrup ◽  
Ida Sterndorff
Keyword(s):  
Fumaric Acid ◽  
Maleic Acid ◽  
Fibrinolytic Activity ◽  
Sodium Citrate ◽  
Plasminogen Activators ◽  
Fibrinolytic Agents ◽  
Enhancing Effect ◽  
Polycarboxylic Acids

Summary1. The presence of citrate in the normal fibrin enhanced the fibrinolytic activity of plasminogen activators, including trypsin. The effect of proteases (on normal or on heated fibrin, containing citrate) was not significantly influenced.2. The effect of plasminogen activators was also increased when excess of plasminogen was present in the normal fibrin plates.3. Fumaric acid and maleic acid belong to the polycarboxylic acids producing an enhancing effect.

New assay of fibrinolytic activity as a continuous rate reaction

1970 ◽  
Vol 48 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Walter H. E. Roschlau ◽  
Sandra L. Miller
Keyword(s):  
Fibrinolytic Activity ◽  
Enzymatic Degradation ◽  
Proteolytic Enzymes ◽  
Plasminogen Activators ◽  
Light Transmittance ◽  
Plasminogen Activation ◽  
Fibrinolytic Agents ◽  
Vitro Assay ◽  
Relative Potencies

A new and rapidly performed in vitro assay of fibrinolytic activity, incorporating turbidimetric measurements of fibrin suspension substrate, is described. The assay allows the write-out of rate reactions by recording the changes in light transmittance through a sample of substrate while it is subjected to enzymatic degradation by fibrinolytic agents. By running the reaction in buffer or serum, the properties of plasminogen activators can be differentiated from those of proteolytic enzymes. Data obtained with this method allow the estimation of relative potencies, quantitative inhibition of enzymes by serum, rate of plasminogen activation, etc., for which examples are given.

Inactivation of Antiplasmin and Complement C1 in Human Plasma Rendered Fibrinolytic by Synthetic Organic Compounds

1963 ◽  
Vol 10 (01) ◽  
pp. 151-163 ◽  
Author(s):  
Kurt N von Kaulla
Keyword(s):  
Human Plasma ◽  
Organic Compounds ◽  
Bovine Serum ◽  
Fibrinolytic Activity ◽  
Plasma Generation ◽  
Synthetic Organic Compounds

SummaryCertain synthetic organic compounds induce upon dissolution marked fibrinolytic activity in human plasma, reduce the antiplasmin titer of human or bovine serum and destroy the complement C1 of human plasma. Generation of fibrinolytic activity and reduction of antiplasmin are concentration-depending time reactions. Destruction of complement C1 occurs almost instantaneously. Minor molecular modifications abolish all three activities of the compounds.

Effect of Bentonite on Fibrinolytic System in Serum

1963 ◽  
Vol 10 (01) ◽  
pp. 120-132 ◽  
Author(s):  
E. S Olesen
Keyword(s):  
Guinea Pig ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
High Potential ◽  
Fibrinolytic System ◽  
Fibrinolytic Agents ◽  
Isoelectric Precipitation ◽  
Active Protease ◽  
Pig Serum

SummaryTreatment of serum with bentonite led to a reduced content of inhibitors of trypsin and urokinase in the isoelectrically precipitated euglobulin, and removed fibrinolytic agents and precursors from serum. Bentonite-treated serum added to untreated serum reduced precipitation of the above inhibitors, and presumably also precipitation of inhibitors against a plasminogen activator of serum.Bentonite-treated serum (whether from pig, ox, guinea-pig, or man), added to untreated guinea-pig serum, produced fibrinolytic activity on isoelectric precipitation of the mixture; the activity of the euglobulin was due to an activator of plasminogen as well as an active protease, probably plasmin. The described effects of bentonite-treated serum are similar to those previously reported for anionic polyelectrolytes. Possible mechanisms are discussed.The “non-specific” activation of fibrinolytic activity by means of bentonite emphasizes that guinea-pig serum [which is characterized by a high potential for “nonspecific” activation of its fibrinolytic system Olesen (1962)] contains all the elements required for the formation of an activator of plasminogen, and thus the activation of its plasminogen to plasmin.

Kaolin-Activated Euglobulin Lysis Time (KELT)

1979 ◽  
Author(s):  
H Greig
Keyword(s):  
No Value ◽  
Clinical Assessment ◽  
Fibrinolytic Activity ◽  
Factor Xii ◽  
Plasminogen Activation ◽  
Normal Range ◽  
Control Subjects ◽  
Lysis Time ◽  
Euglobulin Lysis Time ◽  
The Mean

The most commonly used test for clinical assessment of fibrinolytic activity is the Euglobulin Lysis Time (ELT). However the normal range is very wide, the long times are inconvenient and detection of inhibition is impossible. An attempt has been made to utilise the acceleration of the ELT when kaolin is present, to devise a test with shorter times, a narrower normal range, and better precision. The Euglobulin lysis time was carried out by a modification of the method of NILSSON and OLOW, after precipitation of the euglobulin in the absence of kaolin (ELT) and in the presence of 1 mg. kaolin/ml. plasma (KELT). In 14 control subjects the mean, SD, and range for the ELT were 168.6’, 54.6’, 84-290’; the corresponding values for the KELT were 60.3’, 8.3’ and 46-74’. However, it was found that there was no correlation between the ELT value and the corresponding KELT (’r’ = -0.021); on the contrary, the longer the ELT, the greater the shortening produced by kaolin and there is a direct correlation between the ELT and the shortening of the lysis time by kaolin; ’r’ = 0.988. It is concluded that the KELT has no value as a clinical measure of fibrinolytic activity; further, the results suggest that kaolin may remove an inhibitor(s) of plasminogen activation as well as initiating Factor XII - mediated plasminogen activation.

scholarly journals PHYSIOLOGICAL ROLES AND ASSOCIATED DISORDERS OF ADIPONECTIN

2016 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
Preeti Sharma ◽  
Shailaza Shrestha ◽  
Pradeep Kumar ◽  
Saxena Sp ◽  
Rachna Sharma
Keyword(s):  
Type 2 Diabetes ◽  
Cardiovascular Disease ◽  
Adipose Tissue ◽  
Human Plasma ◽  
Mode Of Action ◽  
Skeletal Muscles ◽  
High Concentration ◽  
Peripheral Tissues ◽  
Cardioprotective Effects

ABSTRACTAmong the adipokines, adiponectin is the first one to be described just over a decade ago. It is produced exclusively by adipose tissue and circulatesin high concentration in human plasma accounting for 0.01% of proteins in plasma, almost thousand times higher than that of leptin. The normalcirculating level of adiponectin ranges from 2 to 30 µg/ml. It is now observed that besides adipose tissue, adiponectin can also be produced byseveral other tissues such as hepatocytes, cardiomyocytes, and placenta. Adiponectin executes its action via autocrine as well as and paracrine effects.Researchers working in this area have revealed that adiponectin has insulin-sensitizing, anti-inflammatory and cardioprotective effects. Our reviewfocuses on adiponectin, its mode of action on different peripheral tissues such as skeletal muscles, heart, liver, brain and its the correlative accountin various diseases.Keywords: Adiponectin, Obesity, Type 2 diabetes, Inflammation, Malignancies, Cardiovascular disease.

scholarly journals Alteration of Streptokinase-Induced Fibrinolysis Under Clinically Relevant Conditions

1977 ◽  
Author(s):  
A.H. Sutor ◽  
G. Wünsch-Macholz ◽  
W. Künzer
Keyword(s):  
Human Plasma ◽  
Fibrinolytic Activity ◽  
Hemoglobin Concentration ◽  
Positive Correlation ◽  
Ph Values

Testing streptokinase-induced fibrinolysis in human plasma we obtained the following results: Optimal fibrinolysis takes part at pH-values between 6.8 and 7.25, at NaCl-concentrations between 0.04 and 0.08 g/1, at temperatures between 36° and 42°, and at streptokinase-concentrations between 0.05 and 2 U/ml plasma. Outside of these ranges fibrinolytic activity is reduced. No correlation was found between streptokinase-induced fibrinolysis and hemoglobin concentration, but a strongly positive correlation between fibrinolysis and erythrocyte stromata concentration.

scholarly journals A sensitive and reliable RP-HPLC method for the detection of cimetidine – a H2 receptor antagonist in human plasma

2019 ◽  
Vol 8 (3) ◽  
pp. 671-674
Keyword(s):  
Human Plasma ◽  
High Performance ◽  
Internal Standard ◽  
Bioequivalence Study ◽  
High Concentration ◽  
H2 Receptor Antagonist ◽  
Chromatography Method ◽  
Thaw Cycle ◽  
Limit Of Quantitation ◽  
The Mean

Bioanalytical methods for bioequivalence studies require high sensibility and rapidity due to the large number of samples and the low plasma concentration of drugs. The present study aimed to develop and validate a high-performance liquid chromatography method to quantify cimetidine (CMT) in human plasma and to apply it in a bioequivalence study. Spiked plasma of 500 µl (l, m and h concentration) was used for the assay. The HPLC injection volume was 20μl of the reconstitute sample where, 2 ml of ethyl acetate used for extraction purposes. Cimetidine was prepared separately for low (80 ng/ml), medium (2000 ng/ml) and high (3600 ng/ml) concentrations and internal standard (ranitidine) concentration was 3000 ng/ml. Freeze thawing and long terms stability were conducted at -25º c. The individual calibration curve for spiked standards was linear with R2= 0.99. The inaccuracy values for QC samples were within 15% of the actual value and not more than 20% for the LOQ. The limit of quantitation (LOQ) was 40 ng/ml, which was also the lowest concentration of cimetidine that was quantitated with the variability of 5.9%. The within day precision and between day precision for LOQ were 10.8 and 5.9 respectively. The retention time for the analyte was 4.1-4.5 minutes during the within a day and between day results. The mean % inaccuracy values for low, medium and high concentration were 6.8, 5.6 and 7.8 respectively for within day and 2.4, 6.1 and 7.9 respectively for between days. The within day and between day % inaccuracy for LOQ concentration was 12.4 and 5.5 respectively. The mean recoveries for low, medium and high concentration of cimetidine were 80.2, 70.9 and 74.2. The overall mean recovery for cimetidine was 75.1%. The maximum inaccuracy for freeze thaw cycle and long term stability samples for low, medium and high was found with CV less than 15% for all concentrations, indicating that cimetidine is stable. The developed method was precise and accurate and was suitable to be applied for the bioequivalence study of cimetidine.

scholarly journals Initiation and regulation of fibrinolysis in human plasma at the plasminogen activator level

Blood ◽  
1987 ◽  
Vol 69 (5) ◽  
pp. 1354-1362 ◽  
Author(s):  
TC Wun ◽  
A Capuano
Keyword(s):  
Human Plasma ◽  
Plasminogen Activator ◽  
Gel Electrophoresis ◽  
Fibrinolytic Activity ◽  
High Rate ◽  
Bovine Aortic Endothelial Cell ◽  
Hep G2 ◽  
Triton X ◽  
Sepharose 4B

The initiation and regulation of fibrinolysis has been studied by reconstitution of fibrinolytic activity in human plasma in vitro. Depletion of tissue plasminogen activator (tPA) antigen by immunoadsorption of human plasma with anti-tPA Ig Sepharose 4B leads to total loss of spontaneous fibrinolytic activity determined by lysis of a thrombin-induced clot. Addition of physiological concentrations of purified tPA to tPA-depleted plasma restores fibrinolytic activity as a function of the length of time between tPA addition and clotting. Addition of free tPA to tPA-depleted plasma followed by immediate clotting results in a high rate of fibrinolysis. In contrast, when free tPA is allowed to incubate in plasma for 10 to 60 minutes prior to clot formation, the fibrinolytic activity of tPA is gradually lost. The loss of tPA-induced fibrinolytic activity in unclotted plasma is accompanied by decreased partitioning of tPA antigen into fibrin after clotting and is kinetically correlated with the formation of a 100 kilodalton (kDa) tPA complex as demonstrated by SDS-gel electrophoresis and fibrin-agar zymography. These results suggest that free tPA is susceptible to complexation by the plasma inhibitor in the absence of a clot. Fibrin formation renders tPA relatively inaccessible to inhibition. The tPA antigen isolated from stored plasma consists mainly of 100 kDa activity in SDS-gel electrophoresis and zymography, indicating that the tPA complex is resistant to dissociation by SDS. Upon rezymography of the sliced gel, only a 60 kDa tPA activity is found, suggesting that the activity at 100 kDa is at least partly due to free tPA dissociated from the complex during the first zymography. Conversion of tPA complex to enzymatically active free tPA also occurs with brief SDS exposure followed by incubation in the presence of excess Triton X-100 or by hydroxylamine treatment. These results reconcile the apparent discrepancy of the 100 kDA inhibitor-tPA complex manifesting plasminogen activation activity during zymography. The plasma tPA- inhibitor complex is precipitated strongly by antisera against plasminogen activator inhibitors (PAIs) of human Hep G2 hepatoma and HT- 1080 fibrosarcoma cells and weakly by antiserum against bovine aortic endothelial cell PAI but not by antiserum against a placental PAI (PAI- 2) suggesting that the plasma inhibitor is immunologically related to Hep G2, HT-1080 and possibly endothedial cell PAIs. Based on the above findings, a simple model for the initiation and regulation of plasma fibrinolysis at the PA level has been formulated.

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