prasugrel-hydrochloride and Disease-Models--Animal

Drugs inhibiting the platelet P2Y. In this study, the pharmacodynamics of a new P2Y. CN-218 had an antiaggregatory efficacy that was at least five times more potent than that of clopidogrel but not as potent as that of prasugrel. It had a significant impact on activated partial thromboplastin time (APTT), whereby the APTT of CN-218-treated rats was approximately 9 s longer than that of the vehicle- or clopidogrel-treated group, while it had no impact on prothrombin time (PT) in rats. CN-218 had a similar potent antithrombotic effect to that of prasugrel and clopidogrel and also reduced the risk of bleeding compared to prasugrel.. CN-218 may be a promising antithrombotic agent, with potent antiplatelet and significant anticoagulant activity, as well as a lower risk of bleeding compared to clopidogrel and prasugrel.

Topics: Animals; Blood Coagulation; Blood Platelets; Carrageenan; Clopidogrel; Cyclic AMP; Disease Models, Animal; Fibrinolytic Agents; Hemorrhage; Male; Mice; Piperidines; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Rats, Wistar; Receptors, Purinergic P2Y12; Thiophenes; Thrombosis

We assessed the effects of ticagrelor, aspirin and prasugrel, started 7days after myocardial ischemia-reperfusion injury on remodeling, inflammation and fibrosis in the rat. We examined whether ticagrelor can affect the number of progenitor cells in the border zone. Ticagrelor, started 24h after myocardial ischemia-reperfusion injury, attenuates the decrease in heart function and adverse remodeling, an effect which is blocked by aspirin.. Rats underwent 40min ischemia followed by reperfusion. Oral dosing with vehicle, ticagrelor (300mg/kg/d), aspirin (20mg/kg/d), their combination or prasugrel (15mg/kg/d) started 7days after infarction. Echocardiography was used to assess systolic function. Heart tissue were analyzed by rt-PCR, immunoblotting, ELISA and immunohistochemistry 2weeks after infarction.. Both ticagrelor and aspirin attenuated the decrease in systolic function and remodeling, an effect that was blocked by their combination. Ticagrelor and aspirin attenuated the increase in ANP, BNP, collagen-I and collagen-III. Again, the effect was blocked by their combination. Ticagrelor increased c-Kit, Sca-1, Ki-67, CD34, attenuated the decrease in CD105 mRNA levels, and attenuated the increase in CD31, whereas aspirin increased Ki-67, suppressed the increase in CD31 and attenuated the decrease in CD105 mRNA levels. Prasugrel did not display any effects.. Ticagrelor attenuated adverse remodeling and deterioration of left ventricular systolic function despite starting treatment after the myocardial ischemia-reperfusion injury is completed. Aspirin had similar effects; however, when combined with ticagrelor, the protective effects were significantly attenuated. Ticagrelor increased the levels of several markers of stem cells and regeneration, suggesting cardiac healing by recruiting regenerative cells into the infarct.

Topics: Animals; Apoptosis; Aspirin; Atrial Natriuretic Factor; Disease Models, Animal; Drug Therapy, Combination; Endoglin; Fibrosis; Gene Expression Regulation; Myocardial Infarction; Myocardial Reperfusion Injury; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Proto-Oncogene Proteins c-kit; Rats; Rats, Sprague-Dawley; Stem Cells; Ticagrelor; Ventricular Function, Left; Ventricular Remodeling

The thienopyridines class of drugs used as P2Y

Topics: Adenosine Diphosphate; Animals; Bleeding Time; Clopidogrel; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Molecular Structure; Platelet Aggregation; Prasugrel Hydrochloride; Prodrugs; Rats; Thienopyridines; Ticlopidine

The efficacy of P2Y12 inhibition for the prevention of cardiovascular events in patients with peripheral arterial disease (PAD) has been established. However, the therapeutic effects on ischemic limb complications are less clear. Accordingly, we aimed to develop a novel murine model of thrombotic hindlimb ischemia to reflect that found in patients with PAD exhibiting ischemic limb symptoms. We further investigated the effects of P2Y12 deficiency and P2Y12 inhibition by prasugrel in this model.. Thrombus formation induced by application of ferric chloride to the femoral artery resulted in a significant reduction in blood flow in the injured limb. In gait analysis using the CatWalk system, moderate difficulties in grounding and weight bearing of the ischemic limb, including reduction of maximum contact area and stance phase duration and increasing in swing phase duration in the ischemic limb, were observed in this model. Blood flow reduction and gait abnormalities gradually recovered over 21 days to levels present before arterial injury. Compared to wild-type (WT) mice, significant increases in blood flow and improvement in gait were observed in P2Y12-deficient mice. In addition, daily oral administration of prasugrel (3 mg/kg per day) to WT mice resulted in significant inhibition of blood flow reduction and gait abnormalities to levels found in P2Y12 deficient mice.. Acute femoral artery thrombosis resulted in hindlimb ischemia and moderate gait abnormalities in mice. In addition, the present study suggests a possible role of P2Y12 in the complications with thrombotic limb ischemia.

Topics: Animals; Disease Models, Animal; Gait; Hindlimb; Ischemia; Mice; Mice, Inbred C57BL; Mice, Knockout; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Regional Blood Flow; Thrombosis

Several clinical trials have demonstrated the benefits of thienopyridine monotherapy in ischaemic stroke patients. Non-human primate models of ischaemic stroke have been used for various antithrombotic agents; however, to the best of our knowledge, there is no data on the effects of P2Y12 antagonists in models, such as the thrombotic middle cerebral artery occlusion (MCAO) monkey model. Accordingly, it remains unclear what level of inhibition of platelet aggregation (IPA) is required for optimal treatment of ischaemic stroke. In the present study, we investigated the effects of prasugrel, a third-generation thienopyridine antiplatelet drug, on platelet aggregation, thrombus formation and cerebral infarct volume in a non-human primate model. Daily oral administration of prasugrel resulted in significant and stable platelet inhibitory effects on Day 3, with IPA values ranging from 31% to 36% at 0.3mg/kg/day and from 44% to 50% at 1mg/kg/day. These IPA levels encompassed values observed in clinical trials of clopidogrel, and were thus selected for further study. In the thrombotic MCAO model, prasugrel increased MCA patency in a dose-dependent manner and significantly reduced ischaemic infarct volume by approximately 70% at 0.3mg/kg/day and 90% at 1mg/kg/day without increasing haemorrhagic infarction. Prasugrel also significantly reduced neurological deficit scores by 60% at 0.3mg/kg/day and 80% at 1mg/kg/day. In conclusion, prasugrel treatment resulted in effective reduction of ischaemic infarction and an associated improvement in neurological function without increasing haemorrhagic infarction. These data suggest that prasugrel monotherapy would be effective for the prevention of thrombotic stroke.

Topics: Adenosine Diphosphate; Administration, Oral; Animals; Blood Pressure; Disease Models, Animal; Dose-Response Relationship, Drug; Haplorhini; Hemorrhage; Infarction, Middle Cerebral Artery; Macaca fascicularis; Male; Myocardial Ischemia; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Receptors, Purinergic P2Y12; Stroke; Thrombosis; Time Factors

Prasugrel, through its active metabolite, reduces atherothrombosis and its clinical manifestations by inhibiting platelet activation and aggregation. Platelets also contribute to inflammation through interaction with different classes of leukocytes. We investigated whether the inhibitory effect of prasugrel on platelets also counteract inflammatory responses. The effect of prasugrel active metabolite, R-138727, was investigated on platelet P-selectin expression, platelet adhesion to polymorphonuclear leukocytes (PMN) and monocytes (MN) and Mac-1 expression in PMN and MN, in vitro, in human cells. The ex vivo effect of prasugrel administration on P-selectin, thromboxane (TXB)2 formation, platelet-PMN conjugates and Mac-1 expression in PMN triggered by PAR-4 agonist peptide was examined in whole blood from healthy mice as well as from mice in which an acute inflammatory reaction was induced by treatment with endotoxin. The effect of prasugrel on inflammatory markers in endotoxin-treated animals was also tested in vivo. R-138727 inhibited agonist-stimulated expression of platelet P-selectin, platelet-PMN and platelet-MN adhesion and platelet-dependent Mac-1 expression in leukocytes. Addition of aspirin did not modify the inhibitory effect elicited by R-138727. Treatment of mice with prasugrel resulted in a profound inhibition of platelet P-selectin expression, TXB2 production, platelet-PMN adhesion and Mac-1 expression in PMN induced by ex vivo stimulation with PAR-4 agonist peptide of whole blood from healthy or endotoxin-treated mice. Measurement of markers revealed that prasugrel reduced TXB2 and tumour necrosis factor-α synthesis and increased nitric oxide metabolites in endotoxin-treated mice in vivo. In conclusion, prasugrel reduces platelet interactions with PMN and MN. Through these effects prasugrel may curb platelet-mediated inflammatory responses.

Topics: Animals; Anti-Inflammatory Agents; Aspirin; Biomarkers; Blood Platelets; Disease Models, Animal; Down-Regulation; Humans; Inflammation Mediators; Leukocytes; Macrophage-1 Antigen; Male; Mice; Mice, Inbred C57BL; Nitric Oxide; Piperazines; Platelet Adhesiveness; Platelet Aggregation Inhibitors; Platelet Function Tests; Prasugrel Hydrochloride; Purinergic P2Y Receptor Antagonists; Selenoprotein P; Shock, Septic; Thiophenes; Thromboxane B2; Tumor Necrosis Factor-alpha

We evaluated the effects of prasugrel, a third-generation thienopyridyl prodrug, on P2Y12 receptors, adenosine 5'-diphosphate (ADP)-induced platelet aggregation, and myocardial infarction (MI) in rats. Oral administration of prasugrel (0.3-3 mg/kg) resulted in the dose-related inhibition of washed platelet aggregation induced by ADP (1-10 μM). Ex vivo [H]-2-MeS-ADP binding to platelet P2Y12 receptors was also inhibited by prasugrel in a similar dose range. The antiaggregatory effects of prasugrel correlated strongly with P2Y12 blockade with correlation coefficients of 0.85-0.92, suggesting that the antiaggregatory activity of prasugrel largely reflected P2Y12 blockade achieved in vivo. We further examined the effects of the in vivo P2Y12 inhibition by prasugrel (1-10 mg/kg, po) on MI induced by thrombotic coronary artery occlusion in rats. In surviving rats, infarct size at 24 hours after photoirradiation was evaluated. In the vehicle group, necrosis area/total left ventricular area was 37.9% ± 6.8% (mean ± SE, n = 7). At all prasugrel doses tested (n = 7 for each dose), necrosis area/total left ventricular area was significantly smaller than that in the vehicle group: 14.4% ± 4.0% for 1 mg/kg (P < 0.01), 19.8% ± 4.5% for 3 mg/kg (P < 0.05), and 14.8% ± 3.6% for 10 mg/kg (P < 0.01). At the highest administered dose of prasugrel (10 mg/kg), blood pressure and heart rate were unchanged. Arrhythmia was observed in 5 of 7 animals in the vehicle group at 24 hours after irradiation; in contrast, no arrhythmia was found in the group treated with prasugrel (10 mg/kg). Taken together, these results demonstrate that prasugrel is a selective P2Y12 inhibitor in vivo, providing effective inhibition of platelet aggregation and MI in rats.

Topics: Animals; Blood Platelets; Blood Pressure; Coronary Occlusion; Coronary Thrombosis; Disease Models, Animal; Drug Evaluation, Preclinical; Electrocardiography; Heart Rate; Male; Myocardial Infarction; Piperazines; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Protein Binding; Purinergic P2 Receptor Antagonists; Rats; Rats, Sprague-Dawley; Receptors, Purinergic P2Y12; Thiophenes

The new P2Y(12) antagonist prasugrel produces greater inhibition of ADP-induced platelet aggregation (IPA) and reduction of thrombotic events in patients versus approved doses of clopidogrel, but increases major bleeding. We examined whether IPA level or P2Y(12) receptor occupancy (RO) could be optimized to better balance the efficacy and bleeding effects of these thienopyridines and reduce the response variability in rabbits. Rabbits were given three daily oral doses of clopidogrel (0.3-30 mg/kg/d), prasugrel (0.03-10 mg/kg/d) or vehicle (n = 6-40/group). Electrically-induced carotid artery thrombosis (AT, % thrombus weight reduction), cuticle bleeding time (BT, fold-increase over control), IPA to 20 microM ADP (% inhibition of peak light transmission) and RO (% inhibition of [(33)P]-2MeS-ADP binding to P2Y(1)-blocked platelets) were determined 2-3 hours after the last dose. ED(50) (doses for half-maximal effect, mg/kg/d) of AT, BT, IPA and RO were 1.6, 6.7, 1.9 and 1.4 for clopidogrel vs. 1.2, 1.9, 0.5 and 0.2 for prasugrel. IPA of 30-40% for both compounds produced the optimal balances of efficacy (AT: 50-60%) and BT of about 2-fold with significant RO of 70-80%. IPA of 50-60% achieved higher efficacy (AT: 60-80%), but with increased BT of five- to six-fold and >90% RO. Box-plot suggests no significant difference in the IPA and RO response variability between both compounds. Clopidogrel was 1.3-7 times less potent than prasugrel in rabbits, depending upon which biomarker was studied. The ratio of efficacy: bleeding was most favorable at a moderate IPA of 30% to 40%. Both compounds had similar IPA and RO response variability.

Topics: Adenosine Diphosphate; Administration, Oral; Animals; Binding, Competitive; Bleeding Time; Clopidogrel; Disease Models, Animal; Dose-Response Relationship, Drug; Fibrinolytic Agents; Hemorrhage; Hemostasis; Male; Piperazines; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2 Receptor Antagonists; Rabbits; Receptors, Purinergic P2; Receptors, Purinergic P2Y12; Thionucleotides; Thiophenes; Thrombosis; Ticlopidine

Prasugrel is an orally available thienopyridyl prodrug with more potent in vivo antiplatelet effects compared to clopidogrel. In the present study, we examined the effects of prasugrel in rat models of cerebral and peripheral arterial occlusive diseases. Cerebral arterial thrombosis was induced by photochemical irradiation of the middle cerebral artery. Prasugrel (3 and 10 mg/kg) dose-relatedly and significantly reduced thrombus-mediated cerebral infarction 24 h after the irradiation. The effect of prasugrel was further examined in an embolic infarction model. Four h after an oral administration of prasugrel, non-occlusive thrombus formation in the right common carotid artery was initiated. In this model, prasugrel (0.3-3 mg/kg) reduced incidence, total area, and total number of cerebral infarcts in a dose-related manner 24 h after the vascular injury. Clopidogrel (10 or 30 mg/kg) was less potent than prasugrel at the doses tested on these thrombotic and embolic infarctions. Finally, the effect of prasugrel on lauric acid-induced peripheral arterial occlusive diseases was evaluated. After injection of lauric acid into the femoral artery, the lesions were scored for the following 10 days as they gradually progressed from the toe throughout the leg. Prasugrel (0.03-3 mg/kg/day) administered from the day before the lauric acid injection for 11 successive days inhibited the progression of the disease in a dose-related manner. Clopidogrel (3-30 mg/kg/day) showed similar effect but its effect was less potent than prasugrel. These results suggest that prasugrel could be a useful drug for preventing thromboembolic diseases including cerebral infarction and peripheral arterial occlusive diseases.

Topics: Animals; Cerebral Arterial Diseases; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Peripheral Vascular Diseases; Piperazines; Prasugrel Hydrochloride; Purinergic P2 Receptor Antagonists; Rats; Rats, Sprague-Dawley; Thiophenes

Ticagrelor (AZD6140), the first reversibly binding oral P2Y(12) receptor antagonist, blocks adenosine diphosphate (ADP)-induced platelet aggregation via a mode of action distinct from that of thienopyridine antiplatelet agents. The latter must be metabolically activated and binds irreversibly to P2Y(12) for the life of the platelet, precluding restoration of hemostatic function without the generation of new platelets. In in vitro studies comparing binding characteristics of ticagrelor and compound 105, a chemical compound indistinguishable from the active metabolite of prasugrel, ticagrelor exhibited 1) an approximately 100-fold higher affinity for P2Y(12) and rapid achievement of equilibrium (vs no equilibrium reached with compound 105) as assessed by radioligand displacement in a receptor filtration binding assay, 2) 48-fold greater potency in a functional receptor assay using recombinant human P2Y(12), and 3) 63-fold greater potency in inhibiting ADP-induced aggregation in washed human platelets. In rat and dog models of thrombosis/hemostasis, there was greater separation between doses that provided antithrombotic effect and those that increased bleeding for ticagrelor compared with clopidogrel and compound 072, a chemical compound indistinguishable from the prasugrel parent compound. The ratio of dose resulting in 3-fold increase in bleeding time to dose resulting in 50% restoration of blood flow in rats was 9.7 for ticagrelor compared with 2.0 for clopidogrel and 1.4 for compound 072. Similar results were observed in dogs. Our findings suggest that reversibility of P2Y(12) binding with ticagrelor may account for the greater separation between antithrombotic effects and increased bleeding compared with the irreversible binding of clopidogrel and prasugrel.

Topics: Adenosine; Animals; CHO Cells; Clopidogrel; Cricetinae; Cricetulus; Disease Models, Animal; Dogs; Hemostasis; Humans; Piperazines; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2 Receptor Antagonists; Pyridines; Rats; Receptors, Purinergic P2; Receptors, Purinergic P2Y12; Thiophenes; Thrombosis; Ticagrelor; Ticlopidine; Transfection

1. CS-747 is a novel antiplatelet agent that generates an active metabolite, R-99224, in vivo. CS-747 itself was totally inactive in vitro. This study examined in vivo pharmacological profiles of CS-747 after single oral administration to rats. 2. Orally administered CS-747 (0.3 - 10 mg kg(-1)) partially but significantly decreased [(3)H]-2-methylthio-ADP binding to rat platelets. CS-747 (3 mg kg(-1), p.o.) treatment neutralized ADP-induced decreases of cyclic AMP concentrations induced by prostaglandin E(1), suggesting that metabolites of CS-747 interfere with G(i)-linked P2T receptor. 3. CS-747 (0.3 and 3 mg kg(-1), p.o.) markedly inhibited ex vivo washed platelet aggregation in response to ADP but not to thrombin. CS-747 also exhibited a marked inhibition of ADP-induced ex vivo platelet aggregation in PRP with a rapid onset (<0.5 h) and long duration (>3 days) of action (ED(50) at 4 h=1.2 mg kg(-1)). 4. R-99224 (IC(50)=45 microM) inhibited in vitro PRP aggregation in a concentration-related manner. 5. CS-747 prevented thrombus formation in a dose-related manner with an ED(50) value of 0.68 mg kg(-1). CS-747 was more potent than clopidogrel (6.2 mg kg(-1)) and ticlopidine (>300 mg kg(-1)). 6. CS-747, clopidogrel, and ticlopidine prolonged the bleeding time. The order of potency of these agents in this activity was the same as that in antiaggregatory and antithrombotic activities. 7. These findings indicate that CS-747 is an orally active and a potent antiplatelet and antithrombotic agent with a rapid onset and long duration of action, and warrants clinical evaluations of the agent.

Topics: Adenosine Diphosphate; Administration, Oral; Animals; Arteriovenous Shunt, Surgical; Binding, Competitive; Bleeding Time; Blood Platelets; Clopidogrel; Collagen; Cyclic AMP; Disease Models, Animal; Dose-Response Relationship, Drug; Fibrinolytic Agents; Male; Piperazines; Platelet Aggregation; Platelet Aggregation Inhibitors; Prasugrel Hydrochloride; Purinergic P2 Receptor Antagonists; Rats; Rats, Sprague-Dawley; Receptors, Purinergic P2; Thionucleotides; Thiophenes; Thrombin; Thrombosis; Ticlopidine; Time Factors; Tritium