A Monoclonal Antibody that Does Not Recognize Tissue-Type Plasminogen Activator Bound to Its Naturally Occurring Inhibitor

1986 ◽  
Vol 56 (03) ◽  
pp. 328-332 ◽  
Author(s):  
Raymond R Schleef ◽  
Nancy V Wagner ◽  
Manjula Sinha ◽  
David J Loskutoff
Keyword(s):  
Monoclonal Antibody ◽  
Plasminogen Activator ◽  
Solid Phase ◽  
Plasminogen Activator Inhibitor ◽  
Cell Types ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Naturally Occurring ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor

SummaryHybridoma clones specific for tissue-type plasminogen activator (tPA) were screened in solid-phase radioimmunoassays for their reactivity toward free tPA and tPA complexed to the endothelial cell-derived, (3-migrating plasminogen activator inhibitor (β-PAI). Two monoclonal antibodies (MABs) were identified with quite distinct properties. The first, MAB LI72D1, bound to free tPA but did not recognize tPA complexed to the β-PAI, whereas the second, MAB HI72C1, bound both to free tPA and to tPA in complex with β-PAI. These properties were maintained when the MABs were immobilized to plastic micro- titer wells, thus permitting the development of immunoradiometric assays (IRMAs) to quantitate free tPA and total tPA antigen in various samples. The IRMAs were employed to analyze the tPA in media conditioned by several human cell types. The results indicate that in some cases, tPA may be present entirely as a free and active enzyme, while in others it apparently exists entirely in complex with β-PAI. Interestingly, some cells appear to contain both forms of tPA.

scholarly journals Kinetic analysis of the interaction between plasminogen activator inhibitor-1 and tissue-type plasminogen activator

1988 ◽  
Vol 256 (1) ◽  
pp. 237-244 ◽  
Author(s):  
C Masson ◽  
E Angles-Cano
Keyword(s):  
Plasminogen Activator ◽  
Solid Phase ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Maximal Velocity ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

The kinetics of inhibition of tissue-type plasminogen activator (t-PA) by the fast-acting plasminogen activator inhibitor-1 (PAI-1) was investigated in homogeneous (plasma) and heterogeneous (solid-phase fibrin) systems by using radioisotopic and spectrophotometric analysis. It is demonstrated that fibrin-bound t-PA is protected from inhibition by PAI-1, whereas t-PA in soluble phase is rapidly inhibited (K1 = 10(7) M-1.s-1) even in the presence of 2 microM-plasminogen. The inhibitor interferes with the binding of t-PA to fibrin in a competitive manner. As a consequence the Kd of t-PA for fibrin (1.2 +/- 0.4 nM) increases and the maximal velocity of plasminogen activation by fibrin-bound t-PA is not modified. From the plot of the apparent Kd versus the concentration of PAI-1 a Ki value of 1.3 +/- 0.3 nM was calculated. The quasi-similar values for the dissociation constants between fibrin and t-PA (Kd) and between PAI-1 and t-PA (Ki), as well as the competitive type of inhibition observed, indicate that the fibrinolytic activity of human plasma may be the result of an equilibrium distribution of t-PA between both the amount of fibrin generated and the concentration of circulating inhibitor.

Effects of Moderate Alcohol Consumption on Platelet Function, Tissue-Type Plasminogen Activator and Plasminogen Activator Inhibitor

1990 ◽  
Vol 63 (03) ◽  
pp. 345-348 ◽  
Author(s):  
J Veenastra ◽  
C Kluft ◽  
Th Ockhuizen ◽  
H v d Pol ◽  
M Wedel ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Plasminogen Activator ◽  
Platelet Function ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Moderate Alcohol Consumption ◽  
Tissue Type Plasminogen Activator ◽  
Postprandial Phase ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor

SummaryShort-term effects of moderate alcohol consumption on platelet function, tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) were studied in two age groups of volunteers (20–30 and 45–55 years), each consisting of eight healthy males. The alcohol (30 g in red port and wine) was consumed during a standard dinner. Two blood samples were drawn: one in the postprandial phase, and one the next morning after fasting overnight. Alcohol consumption tended to increase platelet aggregation and production of hydroxy fatty acids, reduced plasma t-PA activity and increased PAI activity in the postprandial phase. After the overnight fast the effects on t-PA and PAI had disappeared whereas at that time alcohol consumption tended to decrease platelet function. The effects of alcohol on t-PA and PAI activity appeared mainly in the older age group, whereas the t-PA activity in this group was already much lower, irrespective of alcohol consumption.

scholarly journals Cell-Free mRNA Concentrations of Plasminogen Activator Inhibitor-1 and Tissue-Type Plasminogen Activator Are Increased in the Plasma of Pregnant Women with Preeclampsia

2007 ◽  
Vol 53 (3) ◽  
pp. 399-404 ◽  
Author(s):  
Yuditiya Purwosunu ◽  
Akihiko Sekizawa ◽  
Keiko Koide ◽  
Antonio Farina ◽  
Noroyono Wibowo ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Maternal Plasma ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Background: Detection of placental mRNA in maternal plasma has been reported in high-risk pregnancies. We attempted to investigate the concentrations of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (tPA) mRNA in maternal plasma in preeclampsia. Methods: Peripheral blood samples were obtained from healthy pregnant women before and after delivery and also from women with or without preeclampsia. Plasma was isolated from these samples, and RNA was extracted. Plasma PAI-1 and tPA mRNA concentrations were then measured by use of reverse transcription PCR assays. The concentrations were converted into multiples of the median (MoM) of the controls adjusted for gestational age. Data were stratified and analyzed according to the clinical severity of preeclampsia and quantitative distribution of blood pressure and proteinuria. Results: The median (minimum–maximum) PAI-1 mRNA MoM values for women with preeclampsia and controls were 2.48 (0.82–8.53) and 1.00 (0.41–2.33), respectively, whereas the median (minimum–maximum) tPA mRNA MoM values were 3.33 (1.01–10.58) and 1.00 (0.95–1.20), respectively. The concentrations of both PAI-1 and tPA mRNA were significantly increased in cases of preeclampsia, compared with controls (P <0.0001). The MoM values of both mRNA species were directly correlated with the severity of preeclampsia and were greatest among a subgroup of hemolysis, increased liver enzymes, and low platelets pregnancies. Conclusion: Maternal plasma PAI-1 and tPA mRNAs are significantly increased in patients with preeclampsia and are positively correlated with the severity of preeclampsia.

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