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Marcinczyk N, Jarmoc D, Leszczynska A, Zakrzeska A, Kramkowski K, Strawa J, Gromotowicz-Poplawska A, Chabielska E, Tomczyk M. Antithrombotic Potential of Tormentil Extract in Animal Models. Front Pharmacol 2017; 8:534. [PMID: 28860991 PMCID: PMC5559472 DOI: 10.3389/fphar.2017.00534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 07/31/2017] [Indexed: 12/23/2022] Open
Abstract
Potentilla species that have been investigated so far display pharmacological activity mainly due to the presence of polyphenols. Recently, it was shown that polyphenol-rich extract from rhizome of Potentilla erecta (tormentil extract) affects the metabolism of arachidonic acid and exerts both anti-inflammatory and anti-oxidant activities, suggesting a possible effect on thrombosis. Accordingly, the aim of the study was to evaluate the effect of tormentil extract on haemostasis in a rat model of thrombosis. Lyophilized water-methanol extract from P. erecta rhizome was administrated per os for 14 days in doses of 100, 200, and 400 mg/kg in a volume of 2 mL/kg in a 5% water solution of gummi arabici (VEH). In the in vivo experiment an electrically induced carotid artery thrombosis model with blood flow monitoring was used in Wistar rats. Collected blood samples were analyzed ex vivo functionally and biochemically for changes in haemostasis. Tormentil extract (400 mg/kg) significantly decreased thrombus weight and prolonged the time to carotid artery occlusion and bleeding time without changes in the blood pressure. In the ex vivo experiment tormentil extract (400 mg/kg) reduced thromboxane production and decreased t-PA activity, while total t-PA concentration, as well as total PAI-1 concentration and PAI-1 activity remained unchanged. Furthermore, tormentil extract (400 mg/kg) decreased bradykinin concentration and shortened the time to reach maximal optical density during fibrin generation. Prothrombin time, activated partial thromboplastin time, QUICK index, fibrinogen level, and collagen-induced aggregation remained unchanged. To investigate the involvement of platelets in the antithrombotic effect of tormentil, the extract was administrated per os for 2 days to mice and irreversible platelets activation after ferric chloride induced thrombosis was evaluated under intravital conditions using confocal microscopy system. In this model tormentil extract (400 mg/kg) significantly reduced platelet activation at the same extent as acetylsalicylic acid. Taken together, we have shown for the first time that tormentil extract inhibits arterial thrombosis in platelet- and endothelial-dependent mechanisms without hemodynamic changes. Further studies on the detailed mechanism of action of tormentil extract toward fibrinolysis and the kinin system should be carried out.
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Affiliation(s)
- Natalia Marcinczyk
- Department of Biopharmacy, Medical University of BialystokBialystok, Poland
| | - Dominika Jarmoc
- Department of Biopharmacy, Medical University of BialystokBialystok, Poland
| | | | | | - Karol Kramkowski
- Department of Biopharmacy, Medical University of BialystokBialystok, Poland
| | - Jakub Strawa
- Department of Pharmacognosy, Medical University of BialystokBialystok, Poland
| | | | - Ewa Chabielska
- Department of Biopharmacy, Medical University of BialystokBialystok, Poland
| | - Michal Tomczyk
- Department of Pharmacognosy, Medical University of BialystokBialystok, Poland
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Roopmani P, Sethuraman S, Satheesh S, Maheswari Krishnan U. The metamorphosis of vascular stents: passive structures to smart devices. RSC Adv 2016. [DOI: 10.1039/c5ra19109b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The role of nanotechnology enabled techniques in the evolution of vascular stents.
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Affiliation(s)
- Purandhi Roopmani
- Centre for Nanotechnology and Advanced Biomaterials (CeNTAB)
- School of Chemical and Biotechnology
- SASTRA University
- Thanjavur-613 401
- India
| | - Swaminathan Sethuraman
- Centre for Nanotechnology and Advanced Biomaterials (CeNTAB)
- School of Chemical and Biotechnology
- SASTRA University
- Thanjavur-613 401
- India
| | - Santhosh Satheesh
- Jawaharlal Institute of Post Graduate Medical Education and Research (JIPMER)
- Department of Cardiology
- Pondicherry-605 006
- India
| | - Uma Maheswari Krishnan
- Centre for Nanotechnology and Advanced Biomaterials (CeNTAB)
- School of Chemical and Biotechnology
- SASTRA University
- Thanjavur-613 401
- India
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3
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Liou JT, Mao CC, Liu FC, Lin HT, Hung LM, Liao CH, Day YJ. Levobupivacaine differentially suppresses platelet aggregation by modulating calcium release in a dose-dependent manner. ACTA ACUST UNITED AC 2012; 50:112-21. [PMID: 23026170 DOI: 10.1016/j.aat.2012.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 03/20/2012] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Levobupivacaine, an amide local anesthetic widely used in regional anesthesia, is reported in recent studies that it is a potent inhibitor of platelet functions. However, the concentrations of levobupivacaine were limitedly estimated in these reports. Additionally, the mechanisms by which it affects platelet function and blood coagulation is still not entirely known. The purpose of this study was to further investigate its effects on platelet function and the possible signaling mechanisms under various concentrations of levobupivacaine. METHODS Blood samples collected from healthy volunteers were separated into whole blood, platelet-rich-plasma and washed platelets. The effect of levobupivacaine on platelet aggregation was studied using platelet function analyzer (PFA-100) and platelet aggregometer. Agonist-induced platelet adenosine triphosphate (ATP) release, cytosolic calcium mobilization, thromboxane B2 (TxB2) secretion and platelet P-selectin translocation under various concentrations of levobupivacaine were investigated. RESULTS Our results indicated that levobupivacaine possessed negative effect on platelet aggregation. The closure times of (PFA-100) were lengthened and the agonist-induced platelet aggregation was significantly attenuated by levobupivacaine even at a low dose (50 μgml(-1)). Pretreatment with levobupivacaine produced significant changes in agonist-induced platelet P-selectin translocation, ATP release, thromboxane A2 (TxA2) production, and calcium mobilization in a dose-dependent manner. The p38 mitogen-activated protein kinases (MAPK), protein kinase C (PKC) δ subtype, cytosolic phospholipase A2 (cPLA2), and protein kinase B (PKB or Akt) were involved in collagen-induced platelet signaling, which would be responsible for antiplatelet effects of levobupivacaine. CONCLUSION We explored possible targets of levobupivacaine on platelets aggregation signaling mechanisms. Our data revealed that p38 MAPK, PKC δ subtype, cPLA2, and Akt were pathways involved in collagen-induced platelet signaling, which might be responsible for antiplatelet effects of levobupivacaine. Our study did provide direct evidence bolstering the critical mechanisms of levobupivacaine within different contexts. Additionally, levobupivacaine imposed a negative effect on platelet aggregation through multiple signaling pathways.
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Affiliation(s)
- Jiin-Tarng Liou
- Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou, Taiwan, ROC
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4
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Hashimoto M, Sugidachi A, Isobe T, Niitsu Y, Ogawa T, Jakubowski JA, Asai F. The influence of P2Y12 receptor deficiency on the platelet inhibitory activities of prasugrel in a mouse model: evidence for specific inhibition of P2Y12 receptors by prasugrel. Biochem Pharmacol 2007; 74:1003-9. [PMID: 17681285 DOI: 10.1016/j.bcp.2007.06.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 06/14/2007] [Accepted: 06/14/2007] [Indexed: 12/16/2022]
Abstract
Prasugrel is a novel orally active thienopyridine with faster, higher and more reliable inhibition of platelet aggregation than clopidogrel reflecting its metabolism in vivo to an active metabolite with selective P2Y(12) antagonistic activity. Several lines of evidence support the contention that prasugrel provides selective P2Y(12) receptor antagonistic activity. To date, however, direct evidence of P2Y(12) specific action by prasugrel in vivo is limited. In the present study, effects of prasugrel on ex vivo platelet aggregation were examined in wild type (WT) and P2Y(12)(-/-) mice. In WT mice, prasugrel showed platelet inhibition that was 8.2 times more potent than clopidogrel. In P2Y(12)(-/-) mice, ADP induced platelet aggregation was minimal, and its extent was similar to that in prasugrel-treated WT mice. In addition, no further inhibition of platelet aggregation was observed after administration of prasugrel to P2Y(12)(-/-) mice. Furthermore, prasugrel-treated WT mice showed similar aggregation patterns using collagen- and murine PAR-4 agonist peptide to those of P2Y(12)(-/-) mice treated with vehicle or prasugrel. Overall, these results clearly provide additional in vivo evidence that prasugrel has selective P2Y(12) antagonistic activity.
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5
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Fuly AL, Soares AM, Marcussi S, Giglio JR, Guimarães JA. Signal transduction pathways involved in the platelet aggregation induced by a D-49 phospholipase A2 isolated from Bothrops jararacussu snake venom. Biochimie 2005; 86:731-9. [PMID: 15556284 DOI: 10.1016/j.biochi.2004.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2003] [Revised: 07/01/2004] [Accepted: 07/02/2004] [Indexed: 10/26/2022]
Abstract
Bothropstoxin-II (Bthtx-II), an Asp-49 phospholipase A(2) (D-PLA(2)) isolated from Bothrops jararacussu snake venom is able to induce platelet aggregation in a concentration-dependent manner. This effect was not due to the release of ADP from platelets since the aggregation was not suppressed by ADP scavenger systems. PMSF and PPACK were unable to inhibit Bthtx-II-induced platelet aggregation. Thus, a thrombin-like proaggregating activity of Bthtx-II can be excluded as its mechanism of action. On the other hand, indomethacin at low concentrations inhibited more markedly the ATP-release reaction than the aggregation induced by Bthtx-II, indicating that generation of cyclooxigenase products is not the most important event for the platelet aggregation reaction. It was also found that staurosporine and genistein suppressed both platelet aggregation and ATP-release reactions, but not the platelet shape-change induced by Bthtx-II. Substances that either directly activates adenylyl cyclase enzyme (forskolin and PGE(1)) or cell-permeant increasing agents (dibutyril-cAMP) inhibited in a concentration-dependent fashion, the platelet aggregation effects induced by the protein. It is concluded that Bthtx-II induces platelet aggregation and secretion through multiple signal transduction pathways.
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Affiliation(s)
- André L Fuly
- Departamento de Bioquímica Médica, ICB/CCS, Universidade Federal do Rio de Janeiro, 21941-590 Brazil
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6
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Kurata M, Horii I. BLOOD COAGULATION TESTS IN TOXICOLOGICAL STUDIES-REVIEW OF METHODS AND THEIR SIGNIFICANCE FOR DRUG SAFETY ASSESSMENT-. J Toxicol Sci 2004; 29:13-32. [PMID: 15018151 DOI: 10.2131/jts.29.13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In general toxicological studies, prothrombin time and activated partial thromboplastin time are routinely measured to assess blood coagulation. Special (problem-driven) tests for blood coagulation are of significance to detect abnormalities and investigate the mechanism of toxicity in detail. In this review, we compiled widely scattered information on blood coagulation testing from different fields in the biological area, and reviewed the methods available and their significance in toxicological studies. The relevant literature cited here reports large species differences in platelet aggregation, coagulation factors or fibrinolysis, and technical limitations. However, the following tests are basically applicable to laboratory animals; (1) assays for individual coagulation factors and protein induced by vitamin K absence or antagonists (PIVKA) to investigate coagulation factor abnormalities; (2) platelet aggregation-, platelet adhesion-, platelet release-tests and von Willebrand factor assay to screen and/or investigate platelet dysfunction; (3) fibrin/fibrinogen degradation products (FDP), D-dimer and thromboelastogram to detect fibrinolitic abnormalities, and assays for plasminogen, plasmin and their activator/inhibitor to investigate fibrinolysis in detail; and (4) bleeding-time to grossly evaluate blood coagulation capability in vivo. An appropriate battery of these tests provides significant information for risk assessment of drugs.
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Affiliation(s)
- Masaaki Kurata
- Worldwide Safety Sciences, Pfizer Global Research and Development, Nagoya Laboratories, Pfizer Inc., 5-2 Taketoyo, Aichi 470-2393, Japan
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7
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Pyo MK, Yun-Choi HS, Hong YJ. Apparent heterogeneous responsiveness of human platelet rich plasma to catecholamines. Platelets 2003; 14:171-8. [PMID: 12850841 DOI: 10.1080/0953710031000092785] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The platelet-rich plasma (PRP) from 35 healthy Korean volunteers were challenged by four catecholamines and clonidine, which were known as alpha-adrenergic agonists. Wide individual variations were observed with the respect to the pattern and the degree of aggregation in response to each agent. They fall into five distinct groups; Group A (2.9%) was responsive to all five agonists; Group B (28.6%) aggregated in response to (-)-epinephrine, (-)- norepinephrine and epinine; Group C (37.1%) aggregated in response to (-)-epinephrine and (-)-norepinephrine;Group D (11.4%) aggregated only by (-)-epinephrine; Group E (20%) showed impaired responsiveness to all the alpha-agonists tested. All of the non-responding PRP were capable of induction of aggregation in response to (-)-epinephrine, (-)-norepinephrine and epinine in the presence of near-threshold concentration of collagen. Variations were also observed between groups with dopamine and clonidine. Dopamine and clonidine failed to induce secondary aggregation, even in the presence of low concentration of collagen, in most of the PRP preparations belonging to Groups D and E and only slight improvements were observed in the preparations belonging to groups Band C. The observation on heterogeneous responsiveness to catecholamines with PRP of Korean volunteers is quite different from the previous report with PRP of presumably mostly Caucasians.
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Affiliation(s)
- Mi Kyung Pyo
- Natural Products Research Institute, Seoul National University, Seoul 110-460, South Korea
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8
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Arruzazabala MD, Carbajal D, Mas R, Molina V, Casta??o G, G??mez R. Effects of D-003, a New Compound Purified from Sugarcane Wax, on Platelet Aggregation in Healthy Volunteers. Clin Drug Investig 2003. [DOI: 10.2165/00044011-200323020-00004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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9
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Abstract
Epinephrine at even high concentrations neither caused shape change nor aggregation of rat platelets. However, epinephrine induced aggregation in the presence of low (near-threshold) concentrations of collagen at which concentration only platelet shape change was induced without aggregation. The platelet aggregation was also induced by some other catecholamines and clonidine but not by beta-agonist isoproterenol. The aggregatory potencies of R-(-)-isomers, (-)-epinephrine and (-)-norepinephrine were higher than the corresponding desoxy derivatives, epinine and dopamine. In addition, the epinephrine-induced rat platelet aggregation was inhibited by alpha2-antagonists, yohimbine and phentolamine, but not by alpha1-antagonist prazosin or beta-antagonist propranolol. These results suggested that the epinephrine-induced rat platelet aggregation is occurring through alpha2-adrenergic receptors as is the case with human platelets.
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Affiliation(s)
- H S Yun-Choi
- Natural Products Research Institute, Seoul National University, 110-460, Seoul, Republic of Korea.
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10
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Abstract
D-003 is a mixture of higher primary aliphatic saturated acids purified from sugar cane wax whose main component is octacosanoic acid followed by triacontanoic, dotriacontanoic, and tetratriacontanoic acids. The aim of this study was to evaluate the effects of D-003 on: ex vivo platelet aggregation, arterial thrombosis and bleeding time in rats. In addition, time course of antiplatelet effects of D-003 was also investigated on ex vivo platelet aggregation in guinea-pigs. D-003 (25-200 mg kg(-1)) orally administered at single or repeated doses (3 days) inhibited platelet aggregation induced by collagen (2.2 microg ml(-1)) and ADP (2 micromol l(-1)) in rats, and collagen (0.25 microg ml(-1)) induced aggregation in guinea-pigs in a dose-dependent manner. Single doses of D-003 (5-500 mg kg(-1)) administered orally 2 h before induction of arterial thrombosis significantly inhibited the reduction of rectal temperature. D-003 administered at a single dose (50-200 mg kg(-1)) 2 h before the experiment significantly increased the bleeding time in a dose-dependent manner. The time-course effects of D-003 on platelet aggregation, arterial thrombus formation, and bleeding time showed no effect 0.5 h after dosing, and maximal effects exhibited 1-2 h after treatment, whereas no significant effects were found 4 h after treatment.
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Affiliation(s)
- V Molina
- Center of Natural Products, National Center for Scientific Research, Cubanacan, Havana, Cuba
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11
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O'Shaughnessy M, Anderson GL, Pierangeli S, Acland RD, Johnson PC, Peter FW, Barker JH. In vitro platelet aggregation studies in microvascular surgery research: a method in the rat model. Microsurgery 2000; 17:238-42. [PMID: 9140958 DOI: 10.1002/(sici)1098-2752(1996)17:4<238::aid-micr12>3.0.co;2-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
There is now a growing awareness of the central role of platelet function in microvascular thrombosis. Platelet aggregation studies remain one of the most useful ways of studying platelet function and response to different stimuli. This brief communication highlights some of the main variables that can affect platelet aggregation in rats and emphasizes the existence of important differences in these variables compared with human platelet aggregation.
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Affiliation(s)
- M O'Shaughnessy
- Division of Plastic and Reconstructive Surgery, Cork University Hospial, Wilton, Ireland
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12
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Sugidachi A, Asai F, Ogawa T, Inoue T, Koike H. The in vivo pharmacological profile of CS-747, a novel antiplatelet agent with platelet ADP receptor antagonist properties. Br J Pharmacol 2000; 129:1439-46. [PMID: 10742300 PMCID: PMC1571986 DOI: 10.1038/sj.bjp.0703237] [Citation(s) in RCA: 199] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
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.
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Affiliation(s)
- Atsuhiro Sugidachi
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
| | - Fumitoshi Asai
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
- Author for correspondence:
| | - Taketoshi Ogawa
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
| | - Teruhiko Inoue
- Ube Research Laboratory, Ube Industries, Ltd., Kogushi 1978-5, Ube City, Yamaguchi 755-8633, Japan
| | - Hiroyuki Koike
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
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13
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Shiraishi M, Ikeda M, Fujishiro T, Fukuyama K, Ito K. Characteristics of collagen-induced Ca2+ mobilization in bovine platelets. Cell Calcium 2000; 27:53-60. [PMID: 10726211 DOI: 10.1054/ceca.1999.0089] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We characterized the collagen-induced increase in cytosolic Ca2+ ([Ca2+]i) of bovine platelets loaded with the Ca2+ indicator Fura-PE3/AM. Collagen (10 micrograms/ml)-induced increase in [Ca2+]i was only partially inhibited by aspirin, a cyclooxygenase inhibitor, or adenosine 3'-phosphate 5'-phosphosulfate (A3P5PS, a P2Y1 receptor antagonist), while in human platelets it was almost completely suppressed by aspirin. Collagen-induced increase in [Ca2+]i of bovine platelets was inhibited by U73122 (0.3-5 microM), a phospholipase C inhibitor. Collagen (10 micrograms/ml) increased production of inositol 1,4,5-trisphosphate, which was prevented by pretreatment with U73122 (5 microM). Collagen (10 micrograms/ml) accelerated Mn2+ entry, since the rate of Fura-PE3 quenching by Mn2+ was enhanced by 13-fold following stimulation with collagen. U73122 inhibited the acceleration of Mn2+ entry induced by collagen. PGE1 (2.5 microM) partially inhibited the collagen (50 micrograms/ml)-induced increase in [Ca2+]i in bovine platelets but not in human platelets. The data suggest that collagen-induced Ca2+ mobilization in bovine platelets is mediated by phospholipase C. The Ca2+ mobilization in bovine platelets is different from that in human ones as to the dependency on arachidonic acid metabolites and sensitivity to PGE1.
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Affiliation(s)
- M Shiraishi
- Department of Veterinary Pharmacology, Miyazaki University, Japan
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14
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O'Shaughnessy M, Anderson GL, Acland RD, Barker JH. Platelet-derived thromboxane A2 decreases microvascular perfusion after arterial repair. Plast Reconstr Surg 1997; 99:834-41. [PMID: 9047204 DOI: 10.1097/00006534-199703000-00033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Previous work suggests that cod liver oil helps to protect the microcirculation from the consequence of thromboembolic events. The possibility that altered synthesis of thromboxane A2 accounts for the protective effects seen with cod liver oil was investigated in the present study. This was done using the combined thromboxane A2 synthetase inhibitor and thromboxane A2-prostaglandin H2 receptor blocker R68070 (Ridogrel). A standardized microvascular injury was inflicted on the right iliac artery of the rat to generate emboli. The downstream cremaster muscle was used to visualize the passage of the ensuing emboli and to assess the effects of this arterial injury on capillary perfusion and arteriole diameters. The number of visible emboli was not changed by either cod liver oil diet or Ridogrel administration. However, capillary perfusion was preserved by using cod liver oil (n = 7) and was significantly increased by using Ridogrel (n = 7) in comparison with untreated controls (n = 7) in which capillary perfusion was decreased because of the emboli. The administration of Ridogrel to cod liver oil-treated animals (n = 7) provided no additive benefit. The percentage change in A-2 vessel diameters in cod liver oil-treated (n = 7) animals was no different from the control group (n = 7). Ridogrel (n = 7), on the other hand, produced a significant increase in A-3 vessel (n = 21) diameters, but its effects were comparatively less in the cod liver oil-treated animals (n = 7). The formation of platelet aggregates (emboli) appears relatively independent of thromboxane A2 in the rat. Ridogrel is very effective in protecting the microcirculation, and these effects appear to be mediated by A-3 vasodilatation, which, therefore, is at least partially thromboxane A2-dependent. The positive effects of cod liver oil may be mediated by a mechanism that reduces thromboxane A2 synthesis, but further studies are necessary.
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Affiliation(s)
- M O'Shaughnessy
- Division of Plastic and Reconstructive Surgery, Cork University Hospital, Ireland
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15
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Huang TF, Liu CZ, Yang SH. Aggretin, a novel platelet-aggregation inducer from snake (Calloselasma rhodostoma) venom, activates phospholipase C by acting as a glycoprotein Ia/IIa agonist. Biochem J 1995; 309 ( Pt 3):1021-7. [PMID: 7639679 PMCID: PMC1135733 DOI: 10.1042/bj3091021] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A potent platelet aggregation inducer, aggretin, was purified from Malayan-pit-viper (Calloselasma rhodostoma) venom by ionic-exchange chromatography, gel-filtration chromatography and HPLC. It is a heterodimeric protein (29 kDa) devoid of esterase, phospholipase A and thrombin-like activity. Aggretin (> 5 nM) elicited platelet aggregation with a lag period in both human platelet-rich plasma and washed platelet suspension. EDTA (5 mM), prostaglandin E1 (1 microM) and 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester ('TMB-8'; 100 microM) abolished its aggregating activity, indicating that exogenous bivalent cations and intracellular Ca2+ mobilization are essential for aggretin-induced platelet aggregation. Neomycin (4 mM) and mepacrine (50 microM) completely inhibited aggretin (33 nM)-induced aggregation; however, creatine phosphate/creatine phosphokinase (5 mM, 5 units/ml) and indomethacin (50 microM) did not significantly affect its aggregating activity. Aggretin caused a significant increase of [3H]InsP formation in [3H]Ins-loaded platelets, intracellular Ca2+ mobilization and thromboxane B2 formation. Neomycin, a phospholipase C inhibitor, completely inhibited both the increase of [3H]InsP and intracellular Ca2+ mobilization of platelets stimulated by aggretin. A monoclonal antibody (6F1) directed against glycoprotein Ia/IIa inhibited platelet shape change and aggregation induced by aggretin. 125I-aggretin bound to platelets with a high affinity (Kd = 4.0 +/- 1.1 nM), and the number of binding sites was estimated to be 2119 +/- 203 per platelet. It is concluded that aggretin may act as a glycoprotein Ia/IIa agonist to elicit platelet aggregation through the activation of endogenous phospholipase C, leading to hydrolysis of phosphoinositides and subsequent intracellular Ca2+ mobilization.
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Affiliation(s)
- T F Huang
- Pharmacological Institute, College of Medicine, National Taiwan University, Taipei
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16
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Sugidachi A, Asai F, Oshima T, Koike H. Original Article: Intracellular Ca(2+) Mobilization and Aggregatory Response to ADP and Thrombin in Aged Rat Platelets. Platelets 1995; 6:388-93. [PMID: 21043770 DOI: 10.3109/09537109509078477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We previously reported that thrombin-induced Ca(2+) mobilization was enhanced in aged rat platelets. Since Ca(2+) mobilization in platelets is believed to be closely associated with platelet activation, we examined Ca(2+) mobilization and the aggregatory response to ADP and thrombin in young (3 months) and aged (24 months) rat platelets. Blood levels of fibrinogen and Ca(2+) in aged rats were higher than those in young rats. ADP-induced platelet aggregation in aged rats was significantly enhanced in platelet rich plasma and in washed platelet suspension, suggesting that age-associated hyperaggregability to ADP is attributable to changes in platelets themselves. On the other hand, thrombin (0.03-0.3 unit/ml)-induced aggregation in washed platelet suspension from aged rats was comparable to that from young rats. But, thrombin (0.3 unit/ml)-induced intracellular Ca(2+)mobilization was enhanced in aged rat platelets in the presence of extracellular Ca(2+). Likewise, ADP-induced Ca(2+) mobilization was enhanced in aged rat platelets. These results suggest that enhanced Ca(2+) mobilization in aged rat platelets is associated with hyperaggregability to ADP but not to thrombin.
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Affiliation(s)
- A Sugidachi
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co. Ltd, 1-2 58 Hiromachi, Shinagawa-ku, Tokyo 140, Japan
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Arenberger P, Kemény L, Rupec R, Bieber T, Ruzicka T. Langerhans cells of the human skin possess high-affinity 12(S)-hydroxyeicosa tetraenoic acid receptors. Eur J Immunol 1992; 22:2469-72. [PMID: 1325349 DOI: 10.1002/eji.1830220944] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The arachidonic acid metabolite 12-hydroxyeicosatetraenoic acid (12-HETE) is the main eicosanoid formed by epidermal cells and is assumed to play an important role in skin physiology and pathophysiology. Our aim was to find out whether epidermal Langerhans cells possess specific receptors for 12-HETE which would mediate the effects of this eicosanoid in their skin microenvironment. By radioligand binding studies on isolated human Langerhans cells, we could identify specific binding sites for 12(S)-HETE. The analysis of binding data revealed a single class of binding sites with a Kd of 3.32 +/- 0.45 nM and a Bmax of 691,000 +/- 58,000 receptors per cell. The binding was saturable, readily reversible, and specific for 12(S)-HETE. The receptor is likely to mediate the potent chemotactic response of human Langerhans cells towards 12(S)-HETE, which we previously described. Our results strongly suggest that extremely low concentrations of 12-HETE which is formed by epidermal keratinocytes may dramatically influence the biology of Langerhans cells by receptor-mediated effects.
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Affiliation(s)
- P Arenberger
- Department of Dermatology, University Munich, FRG
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Takiguchi Y, Hirata Y, Wada K, Nakashima M. Arterial thrombosis model with photochemical reaction in guinea-pig and its property. Thromb Res 1992; 67:435-45. [PMID: 1412222 DOI: 10.1016/0049-3848(92)90273-d] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have already developed an arterial thrombosis model in the rat femoral artery which utilized photochemical reaction between systemically injected rose bengal and transillumination of a green light with 540 nm wave length from the outside of the vessel. In the present study, we applied this model to guinea-pigs in order to produce a more suitable thrombus model for evaluation of antithrombotic drugs which act on the prostaglandin cascade. In the guinea-pigs, the irradiated femoral artery was completely occluded in 7 min after the injection of rose bengal (10 mg/kg) in a similar manner to the rats. The processes of primary endothelial injury and the subsequent formation of thrombus during this manipulation were observed by the electron microscopy. Pretreatment with aspirin and Y-20811, a thromboxane synthetase inhibitor, significantly prolonged the time required for occlusion in the guinea-pigs, while these drugs were ineffective in the rats. The antithrombotic effect of vapiprost, a thromboxane A2 receptor antagonist, was more pronounced in the guinea-pigs than the rats. In conclusion, this model in guinea-pigs is more suitable for evaluating antithrombotic drugs, particularly, the action of which is exerted involving the prostaglandin cascade.
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Affiliation(s)
- Y Takiguchi
- Department of Pharmacology, Hamamatsu University School of Medicine, Japan
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Violi F, Pratico D, Ghiselli A, Alessandri C, Iuliano L, Cordova C, Balsano F. Inhibition of cyclooxygenase-independent platelet aggregation by low vitamin E concentration. Atherosclerosis 1990; 82:247-52. [PMID: 2115784 DOI: 10.1016/0021-9150(90)90046-l] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Platelet aggregation induced by threshold concentrations of agonists such as collagen, PAF or epinephrine was inhibited in vitro by 100 microM aspirin but was restored by stimulating platelets with high concentrations of collagen, PAF or by a combination of epinephrine and PAF. Incubating aspirin-treated platelets with 50-100 microM vitamin E or vitamin E acetate inhibited platelet aggregation by high concentrations of collagen and PAF and by the combination of epinephrine and PAF; platelet thromboxane A2 formation was less than 10% in samples incubated with 100 microM aspirin. Apyrase, added to aspirin-treated platelet, did not influence platelet aggregation induced by epinephrine and PAF. The present study suggests that concentrations of vitamin E as low as 50-100 microM inhibit cyclooxygenase-independent platelet aggregation when combined with an inhibitor of the arachidonate pathway.
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Affiliation(s)
- F Violi
- Institute of Clinica Medica I, University of Rome, Policlinico Umberto I, Italy
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Piché LA, Mahadevappa VG. Aggregation and/or oxygenated products of arachidonic acid are not required for collagen-induced deacylation of phosphatidylcholine in human platelets. Biochem J 1989; 263:143-8. [PMID: 2513800 PMCID: PMC1133401 DOI: 10.1042/bj2630143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the present study the effects of collagen on platelet aggregation and arachidonic acid (AA) mobilization, specifically from phosphatidylcholine (PC), were investigated in the presence and absence of BW755C, a selective inhibitor of cyclo-oxygenase and lipoxygenases. The inhibition of cyclo-oxygenase and lipoxygenase(s) by BW755C (75 microM) resulted in severe impairment in collagen-induced platelet aggregation. In the presence of BW755C, the aggregation response amounted to 14, 26, 37 and 49% of the corresponding controls (without BW755C) at 10, 25, 50 and 100 micrograms of collagen respectively. On the contrary, the amount of AA released from PC, which ranged from 3.5 to 8.6 nmol/10(9) platelets, in response to the action of collagen (10-100 micrograms) remained unaffected by the presence of BW755C. Substantial amounts of non-esterified AA were detected in the free fatty acid fractions obtained from collagen-stimulated platelets in the presence as well as in the absence of BW755C. However, the presence of BW755C caused a greater accumulation of free AA (mass) and this ranged from 4 to 16 nmol, depending upon the amount of collagen. In addition, small increases in free stearic and oleic acids were observed in collagen-stimulated platelets as compared with unstimulated platelets. The amount of AA lost from PC represented 67, 80, 49 and 52% of the free AA obtained at 10, 25, 50 and 100 micrograms of collagen respectively. Our results adhesion of platelets to collagen fibres may be responsible for much of the AA release from PC Furthermore, these results demonstrate that aggregation and/or cyclo-oxygenase/lipoxygenase metabolites are not obligatory for the release of AA from PC in collagen-stimulated human platelets.
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Affiliation(s)
- L A Piché
- Department of Nutritional Sciences, College of Biological Science, University of Guelph, Ontario, Canada
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Mileikowsky GN, Nadler JL, Huey F, Francis R, Roy S. Evidence that smoking alters prostacyclin formation and platelet aggregation in women who use oral contraceptives. Am J Obstet Gynecol 1988; 159:1547-52. [PMID: 3061301 DOI: 10.1016/0002-9378(88)90592-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Smoking markedly intensifies the risk of cardiovascular disease in women who use oral contraceptives. The mechanism of this effect is not known, but evidence in vitro and in male smokers suggests that nicotine and cigarette smoke can alter prostaglandin formation and platelet function. However, these effects had not been studied with regard to women. We evaluated the effects of smoking on prostacyclin formation and platelet aggregation in 38 women who were matched according to age and weight. These included 24 women who used oral contraceptives (15 smokers, 9 nonsmokers) and 7 smokers who did not use oral contraceptives. In addition, a control group comprised seven healthy, nonsmoking women who did not take oral contraceptives. Prostacyclin formation, reflected by the excretion rate of its stable metabolite 6-keto-prostaglandin F1 alpha, was measured by means of radioimmunoassay in 4-hour urine specimens obtained during a smoking-free period and after participants had inhaled smoke from four high-nicotine cigarettes. In addition, ex vivo platelet aggregation in response to adenosine diphosphate and the stable thromboxane/endoperoxide analog U 46619 was evaluated before and after the inhalation of cigarette smoke. Oral contraceptive users who smoked greater than or equal to 5 years had a lower basal 6-keto-prostaglandin F1 alpha level than nonsmokers or those with a smoking history of less than 5 years (84 +/- 11 versus 159 +/- 28 versus 171 +/- 18 ng/gm of creatinine, p less than 0.01). Inhalation of smoke from four high-nicotine cigarettes did not alter 6-keto-prostaglandin F1 alpha in the smokers who did not use oral contraceptives. However, excretion of 6-keto-prostaglandin F1 alpha was further reduced in the smokers who used oral contraceptives (133 +/- 20 to 86 +/- 9 ng/gm of creatinine, p less than 0.05). Platelet aggregation did not change after inhalation of cigarette smoke in the women who did not take oral contraceptives, but aggregation increased in participants who used oral contraceptives. These results suggest that prostacyclin inhibition may be an important mechanism for the increased cardiovascular risk in women smokers who take oral contraceptives.
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Affiliation(s)
- G N Mileikowsky
- Department of Medicine, University of Southern California School of Medicine, Los Angeles
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