scholarly journals Depression of factor XII-dependent fibrinolytic activity characterizes patients with early myocardial reinfarction after recombinant tissue-type plasminogen activator therapy

1991 ◽  
Vol 18 (2) ◽  
pp. 454-458 ◽  
Author(s):  
Steffen Munkvad ◽  
Jørgen Jespersen ◽  
Jørgen Gram ◽  
Cornelis Kluft
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Tissue Type ◽  
Factor Xii ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

On the Fibrinolytic System in Aged Rats, and Its Reactivity to Endotoxin and Cytokines

1992 ◽  
Vol 67 (06) ◽  
pp. 697-701 ◽  
Author(s):  
J J Emeis ◽  
A Brouwer ◽  
R J Barelds ◽  
M A Horan ◽  
S K Durham ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Fibrinolytic System ◽  
Tissue Type ◽  
High Dose ◽  
Base Line ◽  
Aged Rats ◽  
Tissue Type Plasminogen Activator ◽  
Young Rats ◽  
Type Plasminogen Activator

SummaryAged rats are more susceptible to endotoxin-induced effects, including microthrombosis and platelet aggregation, than are young rats. To investigate whether changes in the fibrinolytic system might be involved, we investigated the fibrinolytic activity in plasma euglobulin fractions and tissues (lung and heart) of young (6-months old) and aged (24-months old) rats under baseline conditions and after challenge with endotoxin. Aged rats had lower plasma levels of tissue-type plasminogen activator (t-PA) and of urokinase-type PA (u-PA) activity. PA inhibitor (PAI) activity was higher in the plasma of aged rats, as was t-PA activity in lung and heart.Rats were treated with either a low dose (1 μg/kg) or a high dose (10 mg/kg) of endotoxin. Both treatments induced a transient phase of increased blood fibrinolytic activity, as evidenced by higher levels of tissue-type plasminogen activator (t-PA) activity and decreased levels of PA inhibitor (PAI) activity. Over time, the fibrinolytic activity decreased, probably due to increased levels of PA inhibitor.Both the early increase in t-PA activity, and the subsequent increase in PAI activity, were more pronounced in the aged rats, as compared with the younger rats, after the high dose of endotoxin. The aged rats also responded to an injection of interleukin-1β or tumor necrosis factor-α with a larger increase of PAI activity than did the younger rats.Together the data suggest that, compared to young rats, aged rats have a decreased base-line plasma fibrinolytic activity, while their fibrinolytic system is more responsive to challenge by endotoxin and cytokines.

scholarly journals Plasminogen activators in dextran sulfate-activated euglobulin fractions: a molecular analysis of factor XII- and prekallikrein- dependent fibrinolysis

Blood ◽  
1989 ◽  
Vol 73 (4) ◽  
pp. 994-999
Author(s):  
J Hauert ◽  
G Nicoloso ◽  
WD Schleuning ◽  
F Bachmann ◽  
M Schapira
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Dextran Sulfate ◽  
Plasminogen Activators ◽  
Contact System ◽  
Tissue Type ◽  
Plasma Kallikrein ◽  
Factor Xii ◽  
Single Chain ◽  
Type Plasminogen Activator

To elucidate the mechanism by which activation of the contact system of blood coagulation leads to expression of fibrinolytic activity, we have determined the molecular characteristics of the plasminogen activators present in dextran sulfate-treated euglobulin fractions by electrophoretic-zymographic analysis and specific immunoadsorption. In addition to free and protease inhibitor-bound tissue-type plasminogen activator (t-PA), dextran sulfate precipitates of euglobulins contained the complex formed between plasma kallikrein and C1-inhibitor, an indicator of prekallikrein activation. These precipitates also contained substantial fibrinolytic activity related to urinary-type plasminogen activator (u-PA). Autoradiographic analysis was then used to evaluate the cleavage of 125I-single-chain u-PA (prourokinase) in dextran sulfate euglobulins as well as after exposure to kallikrein or beta-factor XIIa. This analysis supported the conclusion that plasma kallikrein-mediated cleavage and activation of single-chain u-PA is the mechanism operative for the development of lytic activity in euglobulin precipitates following activation of the contact system.

FIBRINOLYSIS AFTER HEART TRANSPLANTATION

1987 ◽  
Author(s):  
J A Páramo ◽  
R Arcas ◽  
J Fernández ◽  
J Herreros ◽  
R Llorens ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Cardiac Transplantation ◽  
Degradation Products ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Inhibitor Activity ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Activator Inhibitor

Some aspects of the function of the fibrinolytic system were investigated in 12 patients undergoing cardiac transplantation. Plasminogen, euglobulin fibrinolytic activity (EFA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor activity (PAI),α2-antiplasmin (α2-Ap) and fibrinogen degradation products (FDP) were determined preo-peratively and on postoperative days 1 and 5. Results showed a significant decrease of plasminogen (p <0.005), EFA (p <0.0001) and t-PA (p ^.0.001) on postoperative day 1 as compared to the baseline value, followed by recovery on day 5. There was a significant increase of PAI (p < 0 . 005) , α2-AP (p <0.0001) and FDP (p < 0.02) on postoperative day 1 as compared to the preoperative value. PAI and FDP reached the baseline value on postoperative day 5, but α2AP also increased on postoperative day 5. Our data show that there is an impairment in blood fibrinolytic activity early after cardiac transplantation, mainly related to a decrease of plasminogen and t-PA and a increase of PAI and α2AP. The clinical relevance of these data needs further evaluation.

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