Thrombolytic effect of single-chain pro-urokinase in a rabbit jugular vein thrombosis model

Matsuo, Osamu; Bando, Hiroshi; Okada, Kiyotaka; Tanaka, Kenji F.; Tsukada, Masaru; Iga, Yoshiro; Arimura, Hirofumi

doi:10.1016/0049-3848(86)90294-x

Cited by 21 publications

(7 citation statements)

References 11 publications

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“…The rate and extent of thrombolysis after vascular injury can vary considerably amongst patients, whereas the molecular determinants of lysis of arterial thrombi, which are characterized by a high platelet content, are not well understood. The blood fibrinolytic system, which degrades intravascular fibrin, is activated by tissue-type plasminogen activator (t-PA) (2) or by urokinase-type plas-minogen activator (u-PA) (3), enzymes that convert plasminogen to the fibrinolytic protease plasmin (4). However, cofactors, inhibitors or other proteases may also contribute to the regulation of vascular fibrinolysis (4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

Matsuno¹,

Kozawa²,

Niwa³

et al. 1999

Thromb Haemost

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SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.

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Section: Introductionmentioning

confidence: 99%

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

Matsuno¹,

Kozawa²,

Niwa³

et al. 1999

Thromb Haemost

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“…For the most part, these canine models study coronary artery thrombosis initiated either by mechanically inducing endothelial cell damage, or by electrical stimulation of the endothelium in stenosed arteries (1)(2)(3)(4)(5). The rabbit has been studied with regard to the develop-Correspondence to: Dr. Marlene L. Cohen, Lilly Research Laboratories, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA ment of atherosclerosis, balloon catheter injury to the endothelium, effectiveness of thrombolysis and venous thrombosis (6)(7)(8)(9)(10)(11)(12)(13)(14)(15). With regard to arterial thrombosis, previous rabbit models have utilized intravenous injection of thrombin (16), perivascular administration of silver nitrate (17) and radiolabeled platelet accumulation after various arterial insults (18,19,20) either to induce or measure thrombus formation.…”

Section: Introductionmentioning

confidence: 99%

LY53857, a 5HT2 Receptor Antagonist, Delays Occlusion and Inhibits Platelet Aggregation in a Rabbit Model of Carotid Artery Occlusion

et al. 1991

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SummaryThe present study was designed to evaluate the effectiveness of the ergoline 5HT2 receptor antagonist, LY53857 in a rabbit model of vascular arterial occlusion. LY53857 (1 and 10 εM) inhibited serotonin amplified platelet aggregation responses to threshold concentrations of ADP in rabbit platelets in vitro. LY53857 (1 εM) not only inhibited the serotonin component of rabbit platelet aggregation, but also inhibited in vitro aggregation induced by ADP (48.7 ± 16.7% inhibition), collagen (76.1 ± 15.9% inhibition) and U46619 (65.2 ± 12.3% inhibition). The effectiveness of this ergoline 5HT2 receptor antagonist in blocking aggregation to ADP, collagen and U46619 may be related to its ability to inhibit a serotonin component of platelet aggregation since rabbit platelets possess high concentrations of serotonin that may be released during aggregation produced by other agents. Based on the effectiveness of LY53857 to inhibit rabbit platelet aggregation, we explored the ability of LY53857 to extend the time to carotid artery occlusion in rabbits following electrical stimulation of the artery. Reproducible carotid artery occlusion was induced in rabbits by moderate stenosis coupled to arterial cross clamping, followed by electrical stimulation. With this procedure, occlusion occurred at 47.0 ± 7 min (n = 30) after initiation of the electrical stimulation. Animals pretreated with LY53857 (50 to 500 εg/kg i.v.) showed a delay in the time to carotid artery occlusion (at 100 εg/kg i.v. occlusion time extended to 164 ± 16 min). Furthermore, ex vivo platelet aggregation from animals treated with LY53857 (300 εg/kg i.v.) resulted in 40.5% inhibition of platelet aggregation in response to the combination of ADP (1 εM) and serotonin (1 εM). These studies document the ability to obtain reproducible arterial occlusion in the rabbit and showed that intravenously administered LY53857 prolonged the time to carotid artery occlusion. Prolongation of carotid artery occlusion time was accompanied by inhibition of serotonin-amplified ADP-induced aggregation in rabbit platelets, an effect observed both in vitro and ex vivo. Thus, the rabbit is a useful model for studying the effectiveness of 5HT2 receptor antagonists in prolonging vascular occlusion induced by insult of the carotid artery.

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“…A rabbit jugular vein thrombosis model was prepared as described previously (29). Briefly, a section of the jugular vein was exposed and a branch was cannulated.…”

Section: Thrombolysis In a Rabbit Modelmentioning

confidence: 99%

Recombinant Variants of Tissue-type Plasminogen Activator Containing Amino Acid Substitutions in the Fibronectin Finger-like Domain and the Kringle 1 Domain

et al. 1994

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SummaryTissue-type plasminogen activator (t-PA) is a fibrin-specific agent which is used to treat acute myocardial infarction. Pharmacokinetic-ally, t-PA is characterized by a rapid clearance from the circulation. In a previous study, we constructed variant forms of t-PA with genetic modifications at the fibronectin finger-like domain (finger domain) or at the kringle 1 domain (K1 domain). The finger modified variant, t-PA N37S.S38V.G39V.R40E. A41F.Q42S had about a 6.0-fold higher plasma half-life in vivo than wild-type t-PA. Two variants with modifications in the K1 domain, t-PA G161R.K162R.S165W and t-PA N115P, showed an improved kinetic parameters and a 2.2-fold higher plasma half-life in vivo than wild-type t-PA, respectively. To create a recombinant variant of t-PA with a higher enzymatic activity and a further prolonged half-life in vivo, the genes containing each modifications were joined and expressed in animal cells. The two variants, t-PA N37S.S38V G39V.R40E.A41F.Q42S.G161R.K162R.S165W and t-PA N37S.S38V.G39V.R40E.A41F.Q42S.N 115P, were purified from conditioned media and their biochemical, pharmacokinetic and thrombolytic profiles were investigated. Although the variant t-PA N37S.S38V.G39V.R40E.A41F.Q42S.G161R.K162R.S165W demonstrated an impaired enzymatic activity compared to the wild:type t-PA, the half-life of the variant, t-PA N37S.S38V.G39V.R40E.A41F.Q42S. N115P, following intravenous bolus injection in rabbits was considerably longer than that of finger-domain modified variants. Human plasma clot lysis assay estimated the fibrinolytic activity of both variants to be about 2.0-fold less effective than that of the wild-type t-PA. In the rabbit jugular vein clot lysis model, doses of 1.0 and 0.0625 mg/kg were required for about 70% lysis in the wild-type t-PA and t-PA N37S.S38V.G39V.R40E.A41F.Q42S.N115P, respectively. These findings suggested that the variant in this study can be used at a lower dosage in a single bolus injection.

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Thrombolytic effect of single-chain pro-urokinase in a rabbit jugular vein thrombosis model

Cited by 21 publications

References 11 publications

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

Differential Role of Components of the Fibrinolytic System in the Formation and Removal of Thrombus Induced by Endothelial Injury

LY53857, a 5HT2 Receptor Antagonist, Delays Occlusion and Inhibits Platelet Aggregation in a Rabbit Model of Carotid Artery Occlusion

Recombinant Variants of Tissue-type Plasminogen Activator Containing Amino Acid Substitutions in the Fibronectin Finger-like Domain and the Kringle 1 Domain

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