EFFECTS OF INTRAVENOUS ADMINISTRATIONOF A TISSUE-TYPE PLASMINOGEN ACTIVATOR (AK-124) IN ACUTE MYOCARDIAL INFARCTION, INCLUDING CHANGES IN BLOOD COAGULATION AND FIBRINOLYTIC ACTIVITY.- PRELIMINARY REPORT

1987 ◽  
Author(s):  
T Honda ◽  
M Aosaki ◽  
T Tanaka ◽  
M Aosaki ◽  
T Uchida ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Blood Coagulation ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Tissue Type ◽  
Base Line ◽  
Tissue Type Plasminogen Activator ◽  
Human Lung Cells ◽  
Type Plasminogen Activator

We administered a tissue-type plasminogen activator (t-PA) intravenously to 10 patients with acute myocardial infarction (AMI), within 6 hours after the onset of symptoms, and then examined the state of reperfusion by coronary arterio graphy (CAG), and observed changes in blood coagulation and fibrinolytic activity to evaluate the drug effects. AK-124 (produced by Asahi Chemical Industry and Kowa Co., Ltd.in collaboration), a t-PA produced the by tissue cultureof normal human lung cells, was given in a dosage of48,000_576,000 A.K. units by intravenous infusionover 30_45 minutes. In 7 patients who received t-PA, areflow or improved flow was detected on CAG. In t-PAtreated patients, euglobulin lysis activity clearly increased, euglobulin lysis time clearly shortened, and D-dimer increased. After t-PA treatment, the levels of circulating fibrinogen and a2-plasmin inhibitor decreased by an average of 12%, and 14% of base-line values respectively, but plasminogen showed no detectable change. A hematoma at the site of the catheter insertion was observed in one patient. These observations suggest that t-PA has a higher specificity for fibrin bound plasminogen than for plasma plasminogen, and produces coronary thrombolysis without causing systemic fibrinolysis, at least with the above dosage.

Pharmacokinetics and Haemostatic Status During Consecutive Infusions of Recom binant Tissue-Type Plasminogen Activator in Patients with Acute Myocardial Infarction

1989 ◽  
Vol 61 (03) ◽  
pp. 497-501 ◽  
Author(s):  
E Seifried ◽  
P Tanswell ◽  
D Ellbrück ◽  
W Haerer ◽  
A Schmidt
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Plasminogen Activator ◽  
Peak Plasma ◽  
Peak Plasma Concentration ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Precise Control ◽  
Type Plasminogen Activator

SummaryPharmacokinetics and systemic effects of recombinant tissue type plasminogen activator (rt-PA) were determined during coronary thrombolysis in 12 acute myocardial infarction patients using a consecutive intravenous infusion regimen. Ten mg rt-PA were infused in 2 minutes resulting in a peak plasma concentration (mean ±SD) of 3310±950 ng/ml, followed by 50 mg in 1 h and 30 mg in 1.5 h yielding steady state plasma levels of. 2210±470 nglml and 930±200 ng/ml, respectively. All patients received intravenous heparin. Total clearance of rt-PA was 380±74 ml/min, t,½α was 3.6±0.9 min and t,½β was 16±5.4 min.After 90 min, in plasma samples containing anti-rt-PA-IgG to inhibit in vitro effects, fibrinogen was decreased to 54%, plasminogen to 52%, α2-antiplasmin to 25%, α2-macroglobulin to 90% and antithrombin III to 85% of initial values. Coagulation times were prolonged and fibrin D-dimer concentrations increased from 0.40 to 2.7 μg/ml. It is concluded that pharmacokinetics of rt-PA show low interpatient variability and that its short mean residence time in plasma allows precise control of therapy. Apart from its moderate effect on the haemostatic system, rt-PA appears to lyse a fibrin pool in addition to the coronary thrombus.

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.

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