Lys-and Glu-plasminogen potentiate the inhibitory effect of recombinant tissue plasminogen activator on human platelet aggregation

1994 ◽  
Vol 74 (6) ◽  
pp. 555-563 ◽  
Author(s):  
L.Y. Chen ◽  
J.L. Mehta
Keyword(s):  
Platelet Aggregation ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Human Platelet ◽  
Recombinant Tissue Plasminogen Activator ◽  
Inhibitory Effect ◽  
Human Platelet Aggregation ◽  
Tissue Plasminogen

Investigation by HPLC of the Catabolism of Recombinant Tissue Plasminogen Activator in the Rat

1988 ◽  
Vol 60 (01) ◽  
pp. 107-112 ◽  
Author(s):  
Roy Harris ◽  
Louis Garcia Frade ◽  
Lesley J Creighton ◽  
Paul S Gascoine ◽  
Maher M Alexandroni ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Half Life ◽  
Recombinant Tissue Plasminogen Activator ◽  
Rat Plasma ◽  
High Molecular Weight Complex ◽  
Molecular Weights ◽  
Major Activity ◽  
Tissue Plasminogen

SummaryThe catabolism of recombinant tissue plasminogen activator (rt-PA) was investigated after injection of radiolabelled material into rats. Both Iodogen and Chloramine T iodination procedures yielded similar biological activity loss in the resultant labelled rt-PA and had half lives in the rat circulation of 1 and 3 min respectively. Complex formation of rt-PA was investigated by HPLC gel exclusion (TSK G3000 SW) fractionation of rat plasma samples taken 1-2 min after 125I-rt-PA injection. A series of radiolabelled complexes of varying molecular weights were found. However, 60% of the counts were associated with a single large molecular weight complex (350–500 kDa) which was undetectable by immunologically based assays (ELISA and BIA) and showed only low activity with a functional promoter-type t-PA assay. Two major activity peaks in the HPLC fractions were associated with Tree t-PA and a complex having a molecular weight of ̴ 180 kDa. HPLC fractionation to produce these three peaks at various timed intervals after injection of 125I-rt-PA showed each to have a similar initial rate half life in the rat circulation of 4-5 min. The function of these complexes as yet is unclear but since a high proportion of rt-PA is associated with a high molecular weight complex with a short half life in the rat, we suggest that the formation of this complex may be a mechanism by which t-PA activity is initially regulated and finally cleared from the rat circulation.

Inhibitory Effect of Staphylokinase on Platelet Aggregation

1993 ◽  
Vol 70 (05) ◽  
pp. 834-837 ◽  
Author(s):  
Akira Suehiro ◽  
Yoshio Oura ◽  
Motoo Ueda ◽  
Eizo Kakishita
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Degradation Products ◽  
Platelet Rich Plasma ◽  
Inhibitory Effect ◽  
Effective Concentration ◽  
Inhibit Platelet Aggregation ◽  
Platelet Suspension ◽  
Washed Platelet ◽  
Human Platelet Aggregation

SummaryWe investigated the effect of staphylokinase (SAK), which has specific thrombolytic properties, on human platelet aggregation. Platelet aggregation induced with collagen was observed following preincubation of platelets in platelet-rich plasma (PRP) or washed platelet suspension (WP) with SAK at 37° C for 30 min. SAK inhibited platelet aggregation in PRP only at the highest examined concentration (1 x 10-4 g/ml). Although SAK did not inhibit platelet aggregation in WP which contained fibrinogen, it did when the platelets had been preincubated with SAK and plasminogen. The most effective concentration in WP was 1 x 10-6 g/ml. The effect could be inhibited by adding aprotinin or α2-antiplasmin. The highest generation of plasmin in the same preincubation fluid was detected at 1 x 10-6 g/ml SAK. We concluded that SAK can inhibit platelet aggregation in WP by generating plasmin and/or fibrinogen degradation products, but is only partially effective in PRP because of the existence of α2-antiplasmin.

Heparin Counteracts the Antiaggregating Effect of Prostacyclin by Potentiating Platelet Aggregation

1983 ◽  
Vol 49 (02) ◽  
pp. 081-083 ◽  
Author(s):  
Vittorio Bertelé ◽  
Maria Carla Roncaglioni ◽  
Maria Benedetta Donati ◽  
Giovanni de Gaetano
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Effective Inhibitor ◽  
Inhibitory Potency ◽  
Human Platelet Aggregation

SummaryIt has recently been reported that heparin neutralizes the inhibitory effect of prostacyclin (PGI2) on human platelet aggregation. The mechanism of this interaction has not yet been unequivocally established. We present here evidence that heparin (Liquemin Roche) does not react directly with PGI2 but counteracts its inhibitory effect by potentiating platelet aggregation. In the absence of heparin, PGI2 was a less effective inhibitor of platelet aggregation induced by the combination of ADP and serotonin than by ADP alone. Moreover, the inhibitory effect of PGI2 was similarly reduced when increasing the concentrations of ADP (in the absence of heparin). The lack of a specific interaction between heparin and PGI2 is supported by the observation that, in the presence of heparin, other prostaglandins such as PGD2 and PGE1, and a non-prostanoid compound such as adenosine also appeared to lose their inhibitory potency. It is concluded that heparin opposes platelet aggregation inhibitory effect of PGI2 by enhancement of platelet aggregation.

Bioavailability in Rats of Human Recombinant Tissue Plasminogen Activator After Subcutaneous and Intramuscular Injection

1986 ◽  
Vol 56 (03) ◽  
pp. 299-301 ◽  
Author(s):  
L J Garcia Frade ◽  
S Poole ◽  
S Hanley ◽  
L J Creighton ◽  
A D Curtis ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Inferior Vena ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Vena Cava ◽  
Recombinant Tissue Plasminogen Activator ◽  
Fibrin Plate ◽  
Tissue Plasminogen

SummaryThe bioavailability of human recombinant tissue plasminogen activator (rt-PA) in rats was measured after subcutaneous (s.c.) and intramuscular (i.m.) injection. Rt-PA was absorbed after both i.m. and s.c. injection, giving peak plasma concentrations within 30 min and 1 h, respectively, with detectable concentrations up to 6 h. These peak values of bioavailable t-PA were obtained in a functional fibrin plate assay of euglobulin precipitates and expressed as +88% and +243% (for s.c. and i.m. routes respectively) above basal rat fibrinolytic activity. Prior injection of rt-PA, s.c. or i.m., significantly reduced the weights of thrombi induced in the inferior vena cava after injection.

Association of admission leukocyte count with clinical outcomes in acute ischemic stroke patients undergoing intravenous thrombolysis with recombinant tissue plasminogen activator

2020 ◽  
Vol 17 ◽  
Author(s):  
Jie Chen ◽  
Fu-Liang Zhang ◽  
Shan Lv ◽  
Hang Jin ◽  
Yun Luo ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Leukocyte Count ◽  
Intravenous Thrombolysis ◽  
Recombinant Tissue Plasminogen Activator ◽  
Functional Independence ◽  
Tissue Plasminogen ◽  
Poor Outcomes

Objective:: Increased leukocyte count are positively associated with poor outcomes and all-cause mortality in coronary heart disease, cancer, and ischemic stroke. The role of leukocyte count in acute ischemic stroke (AIS) remains important. We aimed to investigate the association between admission leukocyte count before thrombolysis with recombinant tissue plasminogen activator (rt-PA) and 3-month outcomes in AIS patients. Methods:: This retrospective study included consecutive AIS patients who received intravenous (IV) rt-PA within 4.5 h of symptom onset between January 2016 and December 2018. We assessed outcomes including short-term hemorrhagic transformation (HT), 3-month mortality, and functional independence (modified Rankin Scale [mRS] score of 0–2 or 0–1). Results:: Among 579 patients who received IV rt-PA, 77 (13.3%) exhibited HT at 24 h, 43 (7.4%) died within 3 months, and 211 (36.4%) exhibited functional independence (mRS score: 0–2). Multivariable logistic regression revealed admission leukocyte count as an independent predictor of good and excellent outcomes at 3 months. Each 1-point increase in admission leukocyte count increased the odds of poor outcomes at 3 months by 7.6% (mRS score: 3–6, odds ratio (OR): 1.076, 95% confidence interval (CI): 1.003–1.154, p=0.041) and 7.8% (mRS score: 2–6, OR: 1.078, 95% CI: 1.006–1.154, p=0.033). Multivariable regression analysis revealed no association between HT and 3-month mortality. Admission neutrophil and lymphocyte count were not associated with 3-month functional outcomes or 3-month mortality. Conclusion:: Lower admission leukocyte count independently predicts good and excellent outcomes at 3 months in AIS patients undergoing rt-PA treatment.

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