Determination of tissue plasminogen activator in plasma samples by means of a radioimmunoassay

1984 ◽  
Vol 44 (6) ◽  
pp. 495-502 ◽  
Author(s):  
G. Urdén ◽  
M. Blombäck
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasma Samples ◽  
Tissue Plasminogen

Determination of tissue plasminogen activator and its "fast" inhibitor in plasma.

1986 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
J Chmielewska ◽  
B Wiman
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Plasma Samples ◽  
Inhibitor Concentration ◽  
Blood Samples ◽  
Analytical Recovery ◽  
Specific Determination ◽  
Tissue Plasminogen ◽  
Coupled Assay

Abstract We describe efficient, accurate methods for specific determination of tissue plasminogen activator (t-PA, EC 3.4.21.31) and its "fast" inhibitor in plasma. In this coupled assay, a sample containing t-PA is incubated with plasminogen, a plasmin (EC 3.4.21.7) substrate of low Km and high Kcat, and fibrin as a stimulator. The inhibitor of t-PA is determined by incubating the sample with a known amount of t-PA in excess, then determining the residual t-PA. Both t-PA and t-PA inhibitor can be determined in many samples simultaneously within a few hours. These assays are modifications of procedures described by us (Clin Chim Acta 1983;127:279-88 and Thromb Res 1983;31:427-36). Their accuracy as assessed by analytical recovery of pure t-PA added to blood samples (91 +/- 4%) or of partly purified inhibitor added to plasma samples (102 +/- 10%) is satisfactory, as is their precision. For the t-PA assay the CV was 1.6% (within run) or 4.1% (between run). The corresponding values for the inhibitor assay were 4.5% (within run) or 8.4% (between run) if the inhibitor concentration exceeded 3 arb. units/mL.

Immunoreactivity of Tissue Plasminogen Activator and of Its Inhibitor Complexes

1989 ◽  
Vol 61 (03) ◽  
pp. 409-414 ◽  
Author(s):  
M Rånby ◽  
G Nguyen ◽  
P Y Scarabin ◽  
M Samama
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Degradation Products ◽  
Gel Filtration ◽  
Free Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Significant Difference ◽  
Tissue Plasminogen ◽  
Pai 1

SummaryAn enzyme linked immunosorbent assay (ELISA) based on goat polyclonal antibodies against human tissue plasminogen activator (tPA) was evaluated. The relative immunoreactivity of tPA in free form and tPA in complex with inhibitors was estimated by ELISA and found to be 100, 74, 94, 92 and 8l% for free tPA and tPA in complex with PAI-1, PAI-2, α2-antiplasmin and C1-inhibitor, respectively. Addition of tPA to PAI-1 rich plasma resulted in rapid and total loss of tPA activity without detectable loss of ELISA response, indicating an immunoreactivity of tPA in tPA/PAI-1 complex of about l00%. Three different treatments of citrated plasma samples (acidification/reneutralization, addition of 5 mM EDTA or of 0.5 M lysine) prior to determination by ELISA all resulted in increased tPA levels. The fact that the increase was equally large in all three cases along with good analytical recovery of tPA added to plasffi, supported the notion that all tPA antigen present in plasma samples is measured by the ELISA. Analysis by ELISA of fractions obtained by gel filtration of plasma from a patient undergoing tPA treatment identified tPA/inhibitor complexes and free tPA but no low molecular weight degradation products of tPA. Determinations of tPA antigen were made at seven French clinical laboratories on coded and randomized plasma samples with known tPA antigen content. For undiluted samples there was no significant difference between the tPA levels found and those known to be present. The between-assay coefficient of variation was 7 to 10%. In conclusion, the ELISA appeared suited for determination of total tPA antigen in human plasma samples.

An Enzyme Linked Immunosorbent Assay for Determination of Tissue Plasminogen Activator Applied to Patients with Thromboembolic Disease

1983 ◽  
Vol 50 (03) ◽  
pp. 740-744 ◽  
Author(s):  
Nils Bergsdorf ◽  
Torbjörn Nilsson ◽  
Per Wallén
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Specific Activity ◽  
Thromboembolic Disease ◽  
Tissue Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type Plasminogen Activator ◽  
Tissue Plasminogen ◽  
Normal Human

SummaryUtilizing the immunoglobulin fraction from a goat antiserum against human uterine tissue plasminogen activator, an enzyme- linked immunoassay for tissue-type plasminogen activator in human plasma has been developed. With the new method, the concentration of t-PA in normal human acidified plasma is found to be 4.0 ± 1.8 (SD) ng/ml. It increases to 12 ng/ml after a tomiquet test, and to 14 ng/ml after strenous physical exercise. In a group of patients with idiopathic thromboembolic disease, the resting t-PA concentration was 5 ng/ml and the post-occlusion value 16 ng/ml. Furthermore, the patients also exhibited a normal post-occlusion rise in the concentration of plasmin-α2-antiplasmin complex. However, in 37% of the post-occlusion patient plasmas, virtually no increase in t-PA could be detected by a specific activity assay. The results indicate that the reason for a defective post-occlusion fibrinolytic activity in a majority of cases may be the presence of increased concentrations of a fast-acting specific t-PA inhibitor.

A plasmin generation method for the determination of tissue plasminogen activator (t-PA) activity in blood

1989 ◽  
Vol 67 (3) ◽  
pp. 197-203 ◽  
Author(s):  
SCL Koh ◽  
R Yuen ◽  
OAC Viegas ◽  
SE Chua ◽  
BL Ng ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Tissue Plasminogen

scholarly journals Arginine and lysine as products of basic carboxypeptidase activity associated with fibrinolysis

2013 ◽  
Vol 59 (5) ◽  
pp. 570-577
Author(s):  
A.A. Zhloba ◽  
T.F. Subbotina ◽  
D.S. Lupan ◽  
V.A. Bogova ◽  
O.A. Kusheleva
Keyword(s):  
Amino Acids ◽  
Arterial Hypertension ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Local Source ◽  
Clot Lysis ◽  
Plasma Samples ◽  
Natural Substrate ◽  
Tissue Plasminogen

Blood carboxypeptidases play an important role in the regulation of fibrinolysis. We have proposed here the method for the assay of blood carboxypeptidase activity associated with coagulation/fibrinolysis using the natural substrate fibrin and the detection of basic amino acids arginine and lysine as products in the conditions close to those in vivo . Plasma samples from 15 patients with arterial hypertension were investigated. The coagulation and subsequent fibrinolysis were initiated by addition of standard doses of thrombin and tissue plasminogen activator, respectively. Arginine and lysine concentrations before, during, and after completion of fibrinolysis were determined using HPLC. The parameters of fibrinolysis were evaluated by clot turbidity assay. Fibrinolysis led to a large and significant increase in concentrations of arginine and lysine in the incubation mixture by 101 and 81%, respectively. The duration of fibrinolysis initiation significantly correlated to the degree of increase of these amino acids: r =-0.733 и -0.761 for arginine and lysine, respectively (p<0.05). The rates of amino acids liberation during fibrinolysis demonstrate different pattern: arginine generation had two maximums: at the beginning of clot lysis and at his end, whereas the liberation of lysine occurred mainly at the middle of fibrinolysis. Thus, the carboxypeptidase activity associated with fibrinolysis can be considered as a local source of the essential aminoacids.

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