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Caffeic Acid Diminishes the Production and Release of Thrombogenic Molecules in Human Platelets. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0424-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Zhou P, Du S, Zhou L, Sun Z, Zhuo LH, He G, Zhao Y, Wu Y, Zhang X. Tetramethylpyrazine‑2'O‑sodium ferulate provides neuroprotection against neuroinflammation and brain injury in MCAO/R rats by suppressing TLR-4/NF-κB signaling pathway. Pharmacol Biochem Behav 2018; 176:33-42. [PMID: 30171935 DOI: 10.1016/j.pbb.2018.08.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 08/17/2018] [Accepted: 08/28/2018] [Indexed: 01/18/2023]
Abstract
BACKGROUND Neuroinflammation following cerebral ischemia is a serious risk factor in stroke patients. The purpose of this study was to investigate the neuroprotective effects of tetramethylpyrazine‑2'O‑sodium ferulate (TSF), a structurally modified compound from tetramethylpyrazine and ferulate, on cerebral ischemic injury and the underlying mechanisms. METHODS Focal transient cerebral ischemia was induced in rat for 2 h by middle cerebral artery occlusion (MCAO) and the protective effect of TSF was studied using different doses of the drug (10.8, 18, 30 mg/kg, intravenously); Ozagrel (18 mg/kg) was used as the positive control. The drugs were given immediately after MCAO and the efficacy and mechanisms were evaluated at 72 h of reperfusion. The level of pro-inflammatory cytokines such as TNF-α, IL-1β and anti-inflammatory molecules such as IL-10 was measured; other factors such as neurological deficit, brain water content and infarct size and the level of MCP-1, ICAM-1, iNOS, CD11b, TLR-4/NF-κBp65 were also measured. RESULTS TSF at the doses of 18, 30 mg/kg significantly improved neurological deficit, reduced brain water content and infarct size, accompanied by a decrease in the concentration of TNF-α, IL-1β, MCP-1, ICAM-1, iNOS and an increase in the concentration of IL-10. The amount of CD11b and ICAM-1 was found largely decreased and the expression of TLR-4 and the nuclear NF-κBp65 was weakened in TSF-treatment group. CONCLUSIONS Our study suggests that TSF possesses a neuroprotective effect against ischemic stroke which might be mediated through suppression of the inflammatory pathways in the brain following ischemic stroke.
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Affiliation(s)
- Peipei Zhou
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China
| | - Shuzhang Du
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China
| | - Lin Zhou
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China; Laboratory of Accurate Clinical Pharmaceutical of Henan Province, Zhengzhou, Henan 450052, PR China
| | - Zhi Sun
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China; Laboratory of Accurate Clinical Pharmaceutical of Henan Province, Zhengzhou, Henan 450052, PR China
| | - Li Hua Zhuo
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China; Laboratory of Accurate Clinical Pharmaceutical of Henan Province, Zhengzhou, Henan 450052, PR China
| | - Guangwei He
- Hefei Yigong Pharmaceutical Co., Ltd., Hefei, Anhui, PR China
| | - Yan Zhao
- Hefei Yigong Pharmaceutical Co., Ltd., Hefei, Anhui, PR China
| | - Yulin Wu
- Department of Pharmacology, China Pharmaceutical University, Nanjing, PR China.
| | - Xiaojian Zhang
- Pharmaceutical department, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, China; Laboratory of Accurate Clinical Pharmaceutical of Henan Province, Zhengzhou, Henan 450052, PR China.
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Fang W, Wei J, Han D, Chen X, He G, Wu Q, Chu S, Li Y. MC-002 exhibits positive effects against platelets aggregation and endothelial dysfunction through thromboxane A 2 inhibition. Thromb Res 2014; 133:610-5. [DOI: 10.1016/j.thromres.2014.01.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/10/2014] [Accepted: 01/26/2014] [Indexed: 10/25/2022]
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Jincai W, Tingfang D, Yongheng Z, Zhongmin L, Kaihua Z, Xiaohong L. Effects of vinpocetine and ozagrel on behavioral recovery of rats after global brain ischemia. J Clin Neurosci 2013; 21:661-3. [PMID: 24291485 DOI: 10.1016/j.jocn.2013.07.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
Brain ischemia leads to severe disruption of the nervous system and recovery is often prolonged. Rehabilitative post-ischemia pharmacological treatment may therefore be important for behavioral recovery, especially for cognition and motor behavior. The present study investigated the effects of combined vinpocetine and ozagrel administration on the behavioral recovery of rats from global brain ischemia. The results suggest that the combined treatment leads to significantly better improvement compared to single drug administration. We conclude that the combined use of vinpocetine and ozagrel may provide beneficial effects to patients suffering from brain ischemia.
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Affiliation(s)
- Wang Jincai
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China
| | - Dong Tingfang
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China.
| | - Zhang Yongheng
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China
| | - Lu Zhongmin
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China
| | - Zhai Kaihua
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China
| | - Liu Xiaohong
- The First Affiliated Hospital of Xinxiang Medical University, No. 88 Jiankang Road, Weihui 453100, Henan Province, China
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Lee DH, Kim HH, Cho HJ, Bae JS, Yu YB, Park HJ. Antiplatelet effects of caffeic acid due to Ca(2+) mobilizationinhibition via cAMP-dependent inositol-1, 4, 5-trisphosphate receptor phosphorylation. J Atheroscler Thromb 2013; 21:23-37. [PMID: 24088646 DOI: 10.5551/jat.18994] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM In this study, we investigated the effects of caffeic acid (CAFA), a phenolic acid, on Ca(2+)-antagonistic cyclic nucleotides associated with the phosphorylation of inositol 1,4,5-trisphosphate receptor (IP3R) and vasodilator-stimulated phosphoprotein (VASP) and the thromboxane A2 (TXA2)-associated microsomal cyclooxygenase-1 (COX-1) activity in collagen (10 μg/mL)-stimulated platelet aggregation. METHODS Washed platelets (10(8)/mL) obtained from Sprague-Dawley rats (6-7 weeks old, male) were preincubated for 3 minutes at 37℃ in the presence of 2 mM exogenous CaCl2 with or without CAFA or other materials, stimulated with collagen (10 μg/mL) for 5 minutes, then used to determine the levels of intracellular cytosolic Ca(2+) ([Ca(2+)]i), TXA2, cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), COX-1 activity, VASP and IP3R phosphorylation. RESULTS CAFA dose-dependently inhibited collagen-induced platelet aggregation and suppressed the production of TXA2, an aggregation-inducing autacoid associated with the strong inhibition of COX-1 in platelet microsomes exhibiting cytochrome C reductase activity. CAFA dose-dependently inhibited collagen-elevated [Ca(2+)]i mobilization, which was increased by a cAMP-dependent protein kinase (A-kinase) inhibitor, Rp-8-Br-cAMPS, but not a cGMP-dependent protein kinase (G-kinase) inhibitor, Rp-8-Br-cGMPS. In addition, CAFA significantly increased the formation of cAMP and cGMP, intracellular Ca(2+)-antagonists that function as aggregation-inhibiting molecules. CAFA increased IP3R (320 kDa) phosphorylation, indicating the inhibition of IP3-mediated Ca(2+) release from internal stores (i.e. the dense tubular system) via the IP3R on collagen-activated platelets. Furthermore, CAFA-induced IP3R phosphorylation was strongly inhibited by an A-kinase inhibitor, Rp-8-Br-cAMPS, but only mildly inhibited by a G-kinase inhibitor, Rp-8-Br-cGMPS. These results suggest that the inhibition of [Ca(2+)]i mobilization by CAFA is resulted from the cAMP/A-kinase-dependent phosphorylation of IP3R. CAFA elevated the phosphorylation of VASP-Ser(157), an A-kinase substrate, but not the phosphorylation of VASP-Ser(239), a G-kinase substrate. We demonstrate that CAFA increases cAMP and subsequently phosphorylates both IP3R and VASP-Ser(157) through A-kinase activation to inhibit [Ca(2+)]i mobilization and TXA2 production via the inhibition of the COX-1 activity. CONCLUSIONS These results strongly indicate that CAFA is a potent beneficial compound that elevates the level of cAMP-dependent protein phosphorylation in collagen-platelet interactions, which may result in the prevention of platelet aggregation-mediated thrombotic diseases.
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Affiliation(s)
- Dong-Ha Lee
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering, Inje University
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Lee DH, Cho HJ, Kang HY, Rhee MH, Park HJ. Total saponin from korean red ginseng inhibits thromboxane A2 production associated microsomal enzyme activity in platelets. J Ginseng Res 2013; 36:40-6. [PMID: 23717102 PMCID: PMC3659562 DOI: 10.5142/jgr.2012.36.1.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 11/08/2011] [Accepted: 11/08/2011] [Indexed: 11/18/2022] Open
Abstract
Ginseng, the root of Panax ginseng Meyer, has been used frequently in traditional oriental medicine and is popular globally. Ginsenosides, which are the saponins in ginseng, are the major components having pharmacological and biological activities, including anti-diabetic and anti-tumor activities. In this study, we investigated the effects of total saponin from Korean red ginseng (TSKRG) on thrombin-produced thromboxane A2 (TXA2), an aggregating thrombogenic molecule, and its associated microsomal enzymes cyclooxygenase (COX)-1 and TXA2 synthase (TXAS). Thrombin (0.5 U/mL) increased TXA2 production up to 169 ng/10(8) platelets as compared with control (0.2 ng/10(8) platelets). However, TSKRG inhibited potently TXA2 production to the control level in a dose-dependent manner, which was associated with the strong inhibition of COX-1 and TXAS activities in platelet microsomes having cytochrome c reductase activity. The results demonstrate TSKRG is a beneficial traditional oriental medicine in platelet-mediated thrombotic diseases via suppression of COX-1 and TXAS to inhibit production of TXA2.
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Affiliation(s)
- Dong-Ha Lee
- Department of Biomedical Laboratory Science, College of Biomedical Science and Engineering and Regional Research Center, Inje University, Gimhae 621-749, Korea
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Inhibition of platelet aggregation by chlorogenic acid via cAMP and cGMP-dependent manner. Blood Coagul Fibrinolysis 2013; 23:629-35. [PMID: 22885765 DOI: 10.1097/mbc.0b013e3283570846] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In this study, we investigated the effect of chlorogenic acid, a phenolic acid, on collagen (10 μg/ml)-stimulated platelet aggregation. Chlorogenic acid dose-dependently inhibited collagen-induced platelet aggregation, and suppressed the production of thromboxane A2 (TXA2), an intracellular Ca-agonist as an aggregation-inducing autacoidal molecule, which was associated with the strong inhibition of cyclooxygenase (COX)-1 in platelet microsomes having cytochrome c reductase activity. In addition, chlorogenic acid increased significantly the formation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), intracellular Ca-antagonists as aggregation-inhibiting molecules. These results suggest that chlorogenic acid has antiplatelet activity through the reduction of TXA2 and the increase of cAMP and cGMP levels. Therefore, our data demonstrate that chlorogenic acid is a potent inhibitor of collagen-stimulated platelet aggregation, and may be a crucial tool for a negative regulator during platelet activation in thrombotic diseases.
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Yang WC, Zheng ZB, Sun HL, Wang KZ. Synthesis, crystal structure, and properties of a double-helical zinc(II) coordination polymer with Ozagrel drug. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 86:187-190. [PMID: 22078079 DOI: 10.1016/j.saa.2011.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 10/05/2011] [Accepted: 10/14/2011] [Indexed: 05/31/2023]
Abstract
By the reaction of Zn(OAc)(2)·2H(2)O with Ozagrel, (E)-3-(4-((1H-imidazol-1-yl)methyl)phenyl)acrylic acid (Himpaa), a novel coordination polymer [Zn(impaa)(2)](n)(1) was synthesized and was characterized by IR, elemental analysis, single-crystal X-ray diffraction analysis, photoluminescence spectroscopy, and thermogravimetric and differential thermal analysis. The four-coordinate Zn(II) ions are linked into 1D double-helical chain by the deprotonated impaa(-), which is extended into a 3D supramolecular structure through intermolecular C-H···O hydrogen bonds.
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Affiliation(s)
- Wei-Chun Yang
- College of Chemistry and Chemical Engineering, Pingdingshan University, Pingdingshan, Henan 467002, China
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An GH, Sim SY, Jwa CS, Kim GH, Lee JY, Kang JK. Thromboxane A2 synthetase inhibitor plus low dose aspirin : can it be a salvage treatment in acute stroke beyond thrombolytic time window. J Korean Neurosurg Soc 2011; 50:1-5. [PMID: 21892396 DOI: 10.3340/jkns.2011.50.1.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 05/03/2011] [Accepted: 07/01/2011] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE There is no proven regimen to reduce the severity of stroke in patients with acute cerebral infarction presenting beyond the thrombolytic time window. Ozagrel sodium, a selective thromboxane A2 synthetase inhibitor, has been known to suppress the development of infarction. The antiplatelet effect is improved when aspirin is used together with a thromboxane synthetase inhibitor. METHODS Patients with non-cardiogenic acute ischemic stroke who were not eligible for thrombolysis were randomly assigned to two groups; one group received ozagrel sodium plus 100 mg of aspirin (group 1, n=43) and the other 100 mg of aspirin alone (group 2, n=43). Demographic data, cardiovascular risk factors, initial stroke severity [National Institute of Health Stroke Scale (NIHSS) and motor strength scale] and stroke subtypes were analyzed in each group. Clinical outcomes were analyzed by NIHSS and motor strength scale at 14 days after the onset of stroke. RESULTS There were no significant differences in the mean age, gender proportion, the prevalence of cardiovascular risk factors, stroke subtypes, and baseline neurological severity between the two groups. However, the clinical outcome for group 1 was much better at 14 days after the onset of stroke compared to group 2 (NIHSS score, p=0.007, Motor strength scale score, p<0.001). There was one case of hemorrhagic transformation in group 1, but there was no statistically significant difference in bleeding tendency between two groups. CONCLUSION In this preliminary study, thromboxane A2 synthetase inhibitor plus a low dose of aspirin seems to be safe and has a favorable outcome compared to aspirin alone in patients with acute ischemic stroke who presented beyond the thrombolytic time window.
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Affiliation(s)
- Gyu Hwan An
- Department of Neurosurgery, National Medical Center, Seoul, Korea
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Koumura A, Hamanaka J, Kawasaki K, Tsuruma K, Shimazawa M, Hozumi I, Inuzuka T, Hara H. Fasudil and Ozagrel in Combination Show Neuroprotective Effects on Cerebral Infarction after Murine Middle Cerebral Artery Occlusion. J Pharmacol Exp Ther 2011; 338:337-44. [DOI: 10.1124/jpet.110.177675] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Horváth B, Lenzsér G, Benyó B, Németh T, Benko R, Iring A, Hermán P, Komjáti K, Lacza Z, Sándor P, Benyó Z. Hypersensitivity to thromboxane receptor mediated cerebral vasomotion and CBF oscillations during acute NO-deficiency in rats. PLoS One 2010; 5:e14477. [PMID: 21217826 PMCID: PMC3013104 DOI: 10.1371/journal.pone.0014477] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 12/10/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Low frequency (4-12 cpm) spontaneous fluctuations of the cerebrovascular tone (vasomotion) and oscillations of the cerebral blood flow (CBF) have been reported in diseases associated with endothelial dysfunction. Since endothelium-derived nitric oxide (NO) suppresses constitutively the release and vascular effects of thromboxane A(2) (TXA(2)), NO-deficiency is often associated with activation of thromboxane receptors (TP). In the present study we hypothesized that in the absence of NO, overactivation of the TP-receptor mediated cerebrovascular signaling pathway contributes to the development of vasomotion and CBF oscillations. METHODOLOGY/PRINCIPAL FINDINGS Effects of pharmacological modulation of TP-receptor activation and its downstream signaling pathway have been investigated on CBF oscillations (measured by laser-Doppler flowmetry in anesthetized rats) and vasomotion (measured by isometric tension recording in isolated rat middle cerebral arteries, MCAs) both under physiological conditions and after acute inhibition of NO synthesis. Administration of the TP-receptor agonist U-46619 (1 µg/kg i.v.) to control animals failed to induce any changes of the systemic or cerebral circulatory parameters. Inhibition of the NO synthesis by nitro-L-arginine methyl ester (L-NAME, 100 mg/kg i.v.) resulted in increased mean arterial blood pressure and a decreased CBF accompanied by appearance of CBF-oscillations with a dominant frequency of 148±2 mHz. U-46619 significantly augmented the CBF-oscillations induced by L-NAME while inhibition of endogenous TXA(2) synthesis by ozagrel (10 mg/kg i.v.) attenuated it. In isolated MCAs U-46619 in a concentration of 100 nM, which induced weak and stable contraction under physiological conditions, evoked sustained vasomotion in the absence of NO, which effect could be completely reversed by inhibition of Rho-kinase by 10 µM Y-27632. CONCLUSION/SIGNIFICANCE These results suggest that hypersensitivity of the TP-receptor-Rho-kinase signaling pathway contributes to the development of low frequency cerebral vasomotion which may propagate to vasospasm in pathophysiological states associated with NO-deficiency.
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Affiliation(s)
- Béla Horváth
- Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary.
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TNF-alpha induces thromboxane receptor signaling-dependent microcirculatory dysfunction in mouse liver. Shock 2008; 30:463-7. [PMID: 18800000 DOI: 10.1097/shk.0b013e3181673f54] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
TNF-alpha is a critical mediator of hepatic microcirculatory dysfunction during endotoxemia. The present study was to investigate the role of thromboxane A2 (TXA2) and the biological significance of thromboxane prostanoid (TP) receptor signaling in TNF-alpha-mediated hepatic microcirculatory dysfunction in male C57Bl/6 mice. The number of leukocytes adhering to the endothelial cells of the hepatic microvessels (the portal venules, sinusoids, and central venules) and the percentage of nonperfused sinusoids were determined using in vivo fluorescence microscopy. FR167653, an inhibitor of TNF-alpha, was administered 0 and 2 h after LPS injection. A TXA2 synthase inhibitor, OKY-046, was administered 30 min before TNF-alpha injection. Thromboxane prostanoid receptor knockout mice were used to investigate whether TNF-alpha-induced hepatic microcirculatory dysfunction is mediated by endogenously produced TXA2. FR167653 reduced LPS-induced leukocyte adhesion (50%-80%) and the percentage of nonperfused sinusoids (55%). The leukocyte adhesion was increased in the portal venules (8-fold), sinusoids (51-fold), and central venules (73-fold) in TNF-alpha-treated mice, accompanied with an increase in sinusoidal perfusion deficits (8-fold). Alanine aminotransferase levels rose as the adhesion of leukocytes increased. OKY-046 administration before TNF-alpha administration reduced leukocyte adhesion (41%-49% decrease) and sinusoid perfusion deficits (34% decrease). In TP receptor knockout mice, the number of adhering leukocytes, the percentage of nonperfused sinusoids, and alanine aminotransferase levels were lower (by 43%-56%, 41%, and 29%, respectively) than in wild-type counterparts. The results suggest that TP receptor signaling may promote hepatic microcirculatory dysfunction elicited by TNF-alpha. Blockade of TNF-alpha generation and TP receptor signaling may be a good strategy for managing endotoxin-induced hepatic injury.
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Lee S, Morgan GA, Harris NR. Ozagrel reverses streptozotocin-induced constriction of arterioles in rat retina. Microvasc Res 2008; 76:217-23. [PMID: 18718478 DOI: 10.1016/j.mvr.2008.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 07/18/2008] [Accepted: 07/19/2008] [Indexed: 11/30/2022]
Abstract
Retinal blood flow decreases early in the progression of diabetic retinopathy; however, the mediators and mechanisms responsible for this decrease have yet to be determined. In this study, diabetes was induced by streptozotocin in rats, and retinal blood flow was measured via intravital microscopy 1 or 3 weeks following the induction of hyperglycemia. Additionally, retinal arteriolar diameters and flow were measured prior to and following acute administration of the thromboxane synthase inhibitor ozagrel to investigate the potential role of thromboxane in the observed constriction. Minimal changes in the retinal diameters and flow were observed at 1 week of diabetes; however, at 3 weeks of diabetes, arteriolar constriction and decreases in blood flow were significant. Notably, the constriction occurred only in the arterioles that were in closer proximity to the venules draining the retina. Acute administration of ozagrel reversed the constriction of the closely venule-paired arterioles. In summary, the results suggest that thromboxane mediates localized, venule-dependent arteriolar constriction induced by streptozotocin-induced diabetes in rats.
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Affiliation(s)
- Seungjun Lee
- Louisiana State University Health Sciences Center, Department of Molecular and Cellular Physiology, 1501 Kings Highway, Shreveport, LA 71115, USA
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Arii K, Igarashi H, Arii T, Katayama Y. The effect of ozagrel sodium on photochemical thrombosis in rat: therapeutic window and combined therapy with heparin sodium. Life Sci 2002; 71:2983-94. [PMID: 12384182 DOI: 10.1016/s0024-3205(02)02165-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The therapeutic efficacy of ozagrel sodium (ozagrel), alone and in combination with heparin, and its therapeutic time window were studied in a photochemically induced thrombotic cerebral infarction rat model. Cerebral artery thrombosis was induced by irradiating the brain with green light through intact skull using rose bengal as the photosensitizing dye. One set of animals was treated immediately after thrombosis with (1) vehicle, (2) 10 mg/kg ozagrel in saline, intravenously (i.v.), (3) 150 U/kg unfractioned heparin, subcutaneously (s.c.), or (4) ozagrel, i.v. plus heparin, s.c. Infarct volume was significantly smaller and edema was reduced in the ozagrel-treated groups compared to the vehicle-treated group; heparin did not convey additional benefit. In another set of animals, rats were given either vehicle or 10 mg/kg ozagrel in saline, i.v., 60 min or 120 min after induction of thrombosis. Ozagrel reduced infarct volume, but its effect diminished with delayed administration. The therapeutic window was determined to be less than 60 minutes after induction of thrombosis.
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Affiliation(s)
- Kazumasa Arii
- Second Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan.
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