Effect of ticlopidine on platelet aggregation, adherence to damaged vessels, thrombus formation and platelet survival

1985 ◽  
Vol 37 (1) ◽  
pp. 29-43 ◽  
Author(s):  
M. Cattaneo ◽  
P.D. Windcour ◽  
D.A. Somers ◽  
H.M. Groves ◽  
R.L. Kinlough-Rathbone ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Platelet Survival

scholarly journals Effect of aspirin and sodium salicylate on thrombosis, fibrinolysis, prothrombin time, and platelet survival In rabbits with indwelling aortic catheters

Blood ◽  
1983 ◽  
Vol 61 (2) ◽  
pp. 353-361 ◽  
Author(s):  
M Cattaneo ◽  
A Chahil ◽  
D Somers ◽  
RL Kinlough-Rathbone ◽  
MA Packham ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Prothrombin Time ◽  
Whole Blood ◽  
Fibrinolytic Activity ◽  
Sodium Salicylate ◽  
Thrombus Formation ◽  
Significant Inhibition ◽  
Weak Inhibitor ◽  
Platelet Survival ◽  
High Doses

Abstract We have studied the effect of different doses of aspirin on platelet function, PGI2 formation, platelet survival, thrombosis, fibrinolysis, and prothrombin time in rabbits with indwelling aortic catheters. The thrombi formed around indwelling aortic catheters were found to have a large fibrin component, and their formation was inhibited by heparin administration. Thus, in these experiments we examined the effect of aspirin (a weak inhibitor of thrombin-mediated platelet aggregation) under conditions in which thrombin was a major factor in the initiation and growth of the thrombi. Only very high doses of aspirin tended to inhibit thrombus formation over the 5-day period of observation, and a statistically significant inhibition of thrombus formation was produced by equivalent concentrations of sodium salicylate. The failure of high doses of aspirin to achieve a significant inhibition of thrombosis under the conditions of these experiments (whereas an equivalent dose of sodium salicylate was inhibitory) could be due to aspirin inhibition of PGI2 formation. Shortened platelet survival was not affected by aspirin treatment or the dose sodium salicylate that inhibited thrombus formation. The tendency to inhibit thrombus formation appeared to be unrelated to an effect on platelets but was associated with prolongation of the one-stage prothrombin time and increased whole blood fibrinolytic activity; doses of aspirin that inhibited platelet aggregation in response to sodium arachidonate or collagen, and PGI2 formation by the vessel wall, did not have a significant effect on the amount of thrombus present at 5 days. However, the high doses of aspirin that inhibited PGI2 formation were associated with a tendency to increased thrombus formation during the first 3 hr after insertion of the catheter. The results of these experiments show that when thrombin is an important factor in the formation of thrombi, aspirin is a weak inhibitor of thrombosis unless doses are used that provide sufficient salicylate to interfere with blood coagulation and promote whole blood fibrinolytic activity. These results also show that thrombus formation can be inhibited without an apparent change in platelet survival.

scholarly journals Effect of aspirin and sodium salicylate on thrombosis, fibrinolysis, prothrombin time, and platelet survival In rabbits with indwelling aortic catheters

Blood ◽  
1983 ◽  
Vol 61 (2) ◽  
pp. 353-361
Author(s):  
M Cattaneo ◽  
A Chahil ◽  
D Somers ◽  
RL Kinlough-Rathbone ◽  
MA Packham ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Prothrombin Time ◽  
Whole Blood ◽  
Fibrinolytic Activity ◽  
Sodium Salicylate ◽  
Thrombus Formation ◽  
Significant Inhibition ◽  
Weak Inhibitor ◽  
Platelet Survival ◽  
High Doses

We have studied the effect of different doses of aspirin on platelet function, PGI2 formation, platelet survival, thrombosis, fibrinolysis, and prothrombin time in rabbits with indwelling aortic catheters. The thrombi formed around indwelling aortic catheters were found to have a large fibrin component, and their formation was inhibited by heparin administration. Thus, in these experiments we examined the effect of aspirin (a weak inhibitor of thrombin-mediated platelet aggregation) under conditions in which thrombin was a major factor in the initiation and growth of the thrombi. Only very high doses of aspirin tended to inhibit thrombus formation over the 5-day period of observation, and a statistically significant inhibition of thrombus formation was produced by equivalent concentrations of sodium salicylate. The failure of high doses of aspirin to achieve a significant inhibition of thrombosis under the conditions of these experiments (whereas an equivalent dose of sodium salicylate was inhibitory) could be due to aspirin inhibition of PGI2 formation. Shortened platelet survival was not affected by aspirin treatment or the dose sodium salicylate that inhibited thrombus formation. The tendency to inhibit thrombus formation appeared to be unrelated to an effect on platelets but was associated with prolongation of the one-stage prothrombin time and increased whole blood fibrinolytic activity; doses of aspirin that inhibited platelet aggregation in response to sodium arachidonate or collagen, and PGI2 formation by the vessel wall, did not have a significant effect on the amount of thrombus present at 5 days. However, the high doses of aspirin that inhibited PGI2 formation were associated with a tendency to increased thrombus formation during the first 3 hr after insertion of the catheter. The results of these experiments show that when thrombin is an important factor in the formation of thrombi, aspirin is a weak inhibitor of thrombosis unless doses are used that provide sufficient salicylate to interfere with blood coagulation and promote whole blood fibrinolytic activity. These results also show that thrombus formation can be inhibited without an apparent change in platelet survival.

ADP Plays a Key Role in Thrombogenesis in Rats

1988 ◽  
Vol 59 (02) ◽  
pp. 225-230 ◽  
Author(s):  
J P Maffrand ◽  
A Bernat ◽  
D Delebassée ◽  
G Defreyn ◽  
J P Cazenave ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Thrombus Formation ◽  
Vascular Wall ◽  
Cyclooxygenase Inhibitors ◽  
High Dose ◽  
Silk Thread ◽  
Dense Granules ◽  
Prolonged Bleeding Time ◽  
Venous Shunt

SummaryThe relative importance of ADP, arachidonic acid metabolites and serotonin as thrombogenic factors was evaluated in rats by comparing, after oral administration, the effects of two inhibitors of ADP-induced platelet aggregation (ticlopidine and PCR 4099), three cyclo-oxygenase inhibitors (aspirin, triflusal and indobufen) and a selective serotonin 5HT2 receptor antagonist (ketanserin) on platelet aggregation, in four platelet-dependent thrombosis models and on bleeding time. Platelet aggregation induced by ADP and collagen was completely inhibited by ticlopidine and PCR 4099 whereas only the collagen aggregation was reduced by the cyclo-oxygenase inhibitors. Ketanserin or a depletion of platelet serotonin by reserpine did not affect platelet aggregation. Ticlopidine and PCR 4099 greatly prolonged rat tail transection bleeding time. This is probably related to their known ability to inhibit ADP-mediated platelet aggregation. In contrast, the cyclooxygenase inhibitors did not affect bleeding time at all. Reserpine and ketanserin prolonged bleeding time by interfering with the action of serotonin on the vascular wall. Ticlopidine and PCR4099 were very potent antithrombotics in all the models. Aspirin, only at a high dose, inhibited poorly thrombus formation on a silk thread in an arterio-venous shunt, suggesting that the inhibition of cyclo-oxygenase was not responsible. Triflusal was inactive in all models while indobufen slightly reduced thrombus formation in the silk thread and metallic coil models. Ketanserin and reserpine reduced thrombus only in the metallic coil model. Thrombus formation was greatly reduced in fawn-hooded rats, which lack ADP in their platelet dense granules because of a genetic storage pool deficiency. Taken together, the results obtained with the drugs and with the fawn-hooded rats support the concept that ADP plays a key role in thrombogenesis in rats.

Antithrombotic Effects and Bleeding Time Prolongation with Synthetic Platelet GPIIb/llla Inhibitors in Animal Models of Platelet-Mediated Thrombosis

1994 ◽  
Vol 71 (01) ◽  
pp. 095-102 ◽  
Author(s):  
Désiré Collen ◽  
Hua Rong Lu ◽  
Jean-Marie Stassen ◽  
Ingrid Vreys ◽  
Tsunehiro Yasuda ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Bolus Injection ◽  
Cell Injury ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Femoral Vein ◽  
Thrombotic Occlusion ◽  
Antithrombotic Effects

SummaryCyclic Arg-Gly-Asp (RGD) containing synthetic peptides such as L-cysteine, N-(mercaptoacetyl)-D-tyrosyl-L-arginylglycyl-L-a-aspartyl-cyclic (1→5)-sulfide, 5-oxide (G4120) and acetyl-L-cysteinyl-L-asparaginyl-L-prolyl-L-arginyl-glycyl-L-α-aspartyl-[0-methyltyrosyl]-L-arginyl-L-cysteinamide, cyclic 1→9-sulfide (TP9201) bind with high affinity to the platelet GPIIb/IIIa receptor.The relationship between antithrombotic effect, ex vivo platelet aggregation and bleeding time prolongation with both agents was studied in hamsters with a standardized femoral vein endothelial cell injury predisposing to platelet-rich mural thrombosis, and in dogs with a carotid arterial eversion graft inserted in the femoral artery. Intravenous administration of G4120 in hamsters inhibited in vivo thrombus formation with a 50% inhibitory bolus dose (ID50) of approximately 20 μg/kg, ex vivo ADP-induccd platelet aggregation with ID50 of 10 μg/kg, and bolus injection of 1 mg/kg prolonged the bleeding time from 38 ± 9 to 1,100 ± 330 s. Administration of TP9201 in hamsters inhibited in vivo thrombus formation with ID50 of 30 μg/kg, ex vivo platelet aggregation with an ID50 of 50 μg/kg and bolus injection of 1 mg/kg did not prolong the template bleeding time. In the dog eversion graft model, infusion of 100 μg/kg of G4120 over 60 min did not fully inhibit platelet-mediated thrombotic occlusion but was associated with inhibition of ADP-induccd ex vivo platelet aggregation and with prolongation of the template bleeding time from 1.3 ± 0.4 to 12 ± 2 min. Infusion of 300 μg/kg of TP9201 over 60 min completely prevented thrombotic occlusion, inhibited ex vivo platelet aggregation, but was not associated with prolongation of the template bleeding time.TP9201, unlike G4120, inhibits in vivo platelet-mediated thrombus formation without associated prolongation of the template bleeding time.

Antiplatelet Effect of FK633, a Platelet Glycoprotein Ilb/IIIa Antagonist, on Thrombus Formation and Vascular Patency after Thrombolysis in the Injured Hamster Carotid Artery

1997 ◽  
Vol 77 (03) ◽  
pp. 562-567 ◽  
Author(s):  
Takehiro Kaida ◽  
Hiroyuki Matsuno ◽  
Masayuki Niwa ◽  
Osamu Kozawa ◽  
Hideo Miyata ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Carotid Artery ◽  
Vascular Injury ◽  
Bleeding Time ◽  
Thrombus Formation ◽  
Separate Experiment ◽  
Platelet Glycoprotein ◽  
Neointima Formation ◽  
Vascular Patency ◽  
Injured Artery

SummaryThe antithrombotic and restenosis-preventing effects of FK633, an inhibitor of platelet aggregation via binding to the glycoprotein (GP) Ilb/IIIa receptor, were studied. IC50 value of FK633 against platelet aggregation ex vivo induced by 2.5 |iM adenosine diphosphate (ADP) was 5.4 X 10"7 M as determined using hamster platelet rich plasma. The inhibitory effect was also investigated in vivo on thrombus formation at the carotid arterial wall injured by a modified catheter. As a control, the left carotid artery was injured and the time required to develop a thrombotic occlusion (3.9 ±1.1 min, mean ± S.E.M., n = 18) was determined. Then, the right carotid artery of the same animal was injured while a continuous intravenous (i.v.) infusion of FK633 was administered at doses of 0 (saline), 0.1,0.3 or 1.0 mg/kg/h. The time to occlusion was dose-dependently prolonged. In a separate experiment, 10% of the total tPA dose (0.52 mg/kg) was injected into the injured artery as a bolus and the remaining was infused i.v. at a constant rate for 30 min. When FK633 (0.3 or 1.0 mg/kg/h) was infused together with tPA, late patency of the reperfused artery was much improved as compared with that of treatment with tPA alone. Bleeding time, measured at the end of the tPA infusion, was markedly prolonged when the higher dose of FK633 (1.0 mg/kg/h) was coadministered, however coadministration of the lower dose of FK633 (0.3 mg/kg/h) was almost without prolongation on the bleeding time, despite a significant effect on the vascular patency after thrombolysis. Next, neointima formation was evaluated 2 weeks after the vascular injury. When FK633 (0.3 mg/kg/h) was continuously infused i. v. by an implanted osmotic pump for 3,7 or 14 days after the vascular injury, the neointimal area formation was significantly suppressed in the treatment groups for 7 or 14 days. These findings suggest that FK633 inhibits platelet activation in the injured artery and improves vascular patency after thrombolysis with tPA with a concomitant suppression of neointima formation.

Inhibitory effects of Qushuanling Capsule (祛栓灵胶囊) on thrombus formation and platelet aggregation in rats

2012 ◽  
Vol 19 (2) ◽  
pp. 137-142
Author(s):  
Jie Xue ◽  
Ke-ping Zhang ◽  
Lu-jia Zhu ◽  
Mei-lin Xie ◽  
Hong-quan Zhang
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Inhibitory Effects

The Antiaggregating and Antithrombotic Activity of Clopidogrel Is Potentiated by Aspirin in Several Experimental Models in the Rabbit

1998 ◽  
Vol 80 (09) ◽  
pp. 512-518 ◽  
Author(s):  
Frédérique Dol ◽  
André Bernat ◽  
Robert Falotico ◽  
Alain Lalé ◽  
Pierre Savi ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Carotid Artery ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Experimental Models ◽  
Arteriovenous Shunt ◽  
Thrombotic Occlusion ◽  
Antithrombotic Activity ◽  
Rabbit Carotid Artery ◽  
Antithrombotic Efficacy

SummaryIt is unknown whether the addition of aspirin might increase both the efficacy and the potency of clopidogrel, a potent and selective ADP blocker. For that purpose, the efficacy of clopidogrel (1–20 mg/kg, p.o.) administered orally to rabbits alone or in combination with aspirin (0.1–10 mg/kg, p.o.) was determined in several experimental models. A potent synergistic effect of the clopidogrel/aspirin association was demonstrated with regard to collagen-induced platelet aggregation measured ex vivo. Similarly, aspirin potentiated the antithrombotic activity of clopidogrel measured with regard to experimental thrombosis induced by a silk thread or on stents placed in an arteriovenous shunt, thrombus formation following electrical stimulation of the rabbit carotid artery and with regard to 111In-labeled platelet deposition on a stent implanted in an arteriovenous shunt or on the subendothelium following air drying injury of the rabbit carotid artery. A similar potentiating effect of aspirin was obtained with regard to myointimal proliferation (restenosis) in the femoral arteries of atherosclerotic rabbits which occurred as a consequence of stent placement. The clopidogrel/aspirin combination showed only additive-type effects on bleeding time prolongation induced by ear transection in the rabbit, therefore showing that combined inhibition of cyclooxygenase and ADP‘s effects provide a marked enhanced antithrombotic efficacy. Such a combination may provide substantial protection against platelet aggregation leading to thrombotic occlusion at sites of endothelial injuries and coronary artery stenosis in humans.

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