• YAKHAK HOEJI
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• v.54 no.5
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• pp.392-397
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• 2010

The aim of present study was to investigate the possible influence and related mechanism of additional alcohol on the flavonoid- induced arterial relaxation. Agonist-induced vascular smooth muscle contractions involve the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in quercetin-induced relaxation cotreated with alcohol in rat aortae contracted with phorbol ester, fluoride or thromboxane $A_2$ mimetic U-46619. We hypothesized that cotreated alcohol plays a role in vascular relaxation evoked by quercetin in rat aortae. Endothelium-denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Quercetin inhibited phorbol ester, fluoride or thromboxane $A_2$-induced contraction regardless of endothelial function. However, alcohol didn't decrease any agonist-induced contraction. Interestingly, only in thromboxane $A_2$-induced contraction, synergistic results were observed in aortae denuded and cotreated with quercetin and alcohol suggesting that additional pathways different from antioxidation or endothelial nitric oxide synthesis might be involved in the vasorelaxation. In conclusion, in the agonists-contracted rat aortae, quercetin and alcohol together showed synergistic response regardless of endothelial function in an agonist-dependent manner.

• Molecules and Cells
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• v.27 no.2
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• pp.191-198
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• 2009

The present study was undertaken to determine whether treatment with genistein, the plant-derived estrogen-like compound influences agonist-induced vascular smooth muscle contraction and, if so, to investigate related mechanisms. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Genistein completely inhibited KCl-, phorbol ester-, phenylephrine-, fluoride- and thromboxane $A_2$-induced contractions. An inactive analogue, daidzein, completely inhibited only fluoride-induced contraction regardless of endothelial function, suggesting some difference between the mechanisms of RhoA/Rho-kinase activators such as fluoride and thromboxane $A_2$. Furthermore, genistein and daidzein each significantly decreased phosphorylation of MYPT1 at Thr855 had been induced by a thromboxane $A_2$ mimetic. Interestingly, iberiotoxin, a blocker of large-conductance calcium-activated potassium channels, did not inhibit the relaxation response to genistein or daidzein in denuded aortic rings precontracted with fluoride. In conclusion, genistein or daidzein elicit similar relaxing responses in fluoride-induced contractions, regardless of tyrosine kinase inhibition or endothelial function, and the relaxation caused by genistein or daidzein was not antagonized by large conductance $K_{Ca}$-channel inhibitors in the denuded muscle. This suggests that the RhoA/Rho-kinase pathway rather than $K^+$- channels are involved in the genistein-induced vasodilation. In addition, based on molecular and physiological results, only one vasoconstrictor fluoride seems to be a full RhoA/Rho-kinase activator; the others are partial activators.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.352-356
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• 2012

The present study was undertaken to determine whether ethanol influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Ethanol significantly inhibited thromboxane $A_2$ mimetic-induced contraction with intact endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction irrespective of endothelium suggesting that the pathway such as Rho-kinase activation, $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, ethanol didn't decrease thromboxane $A_2$ mimetic-induced increase of phospho-myosin phosphatase targeting subunit protein 1 (pMYPT1) or pERK1/2. Interestingly, ethanol didn't inhibit significantly phorbol ester-induced contraction in denuded muscles suggesting that thin filament regulation is less important on the ethanol-induced regulation in the muscle than endothelial NO synthesis. In conclusion, this study provides the evidence and possible related mechanism concerning the effect of ethanol on the agonist-dependent contraction in rat aortic rings with regard to endothelial function.

• Biomedical Science Letters
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• v.21 no.4
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• pp.188-197
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• 2015

In this study, we investigated the effect of rice bran water extract fermented with Lactobacillus plantarum Hong (RBLw), on activities of cyclooxygenase-1 (COX-1) and thromboxane $A_2$ synthase (TXAS), thromboxane $A_2$ ($TXA_2$) production associated microsomal enzymes and evaluated its the antiplatelet effect. RBLw, containing 13.5 mg of ferulic acid, dose-dependently inhibited ADP-induced platelet aggregation, and inhibited the production of $TXA_2$, an aggregation molecule. In addition, RBLw directly inhibited COX-1 activity in a dose-dependent manner, but not TXAS activity in platelet microsomal fraction having cytochrome c reductase (an endoplasmic reticulum marker enzyme) activity and expressing COX-1 (72 kDa) and TXAS (60.5 kDa) proteins. These results suggest that RBLw selectively inhibited the activity of COX-1 rather than TXAS to attenuate $TXA_2$ production in ADP-activated platelets. Thus, we demonstrate that RBLw might have direct COX-1 antagonistic function for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.1-5
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• 2011

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.

• YAKHAK HOEJI
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• v.58 no.4
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• pp.223-228
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• 2014

The present study was undertaken to investigate the influence of sulforaphane on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that sulforaphane, the primary ingredient of broccoli of cruciferous vegetables, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Intact of denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, sulforaphane significantly inhibited fluoride, phorbol ester or thromboxane $A_2$ mimetic-induced contraction in denuded muscles suggesting that additional pathways different from endothelial nitric oxide synthesis such as inhibition of Rho-kinase or MEK might be involved in the vasorelaxation. Furthermore, sulforaphane inhibited thromboxane $A_2$-induced increases in pERK1/2 levels suggesting the mechanism including inhibition of thromboxane $A_2$-induced increases in ERK1/2 phosphorylation. This study provides evidence that sulforaphane induces vascular relaxation through inhibition of Rho-kinase or MEK in rat aortae.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.122-126
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• 1996

In vitro inhibitory effect of aspalatone ((3-(2-methyl-4-pyronyl)]-2-acetyloxybenzoate) on collagen-, ADP-, and epinephrine-induced platelet aggregation in human platelet rich plasma (PRP) was compared with the effects of reference drugs (acetylsalicylic acid, cilostazol and ticlopidine). Aspalatone inhibited time and dose dependently human platelet aggregation induced by collagen; relative potency was in the order of cilostazol>acetylsalicylic acid>aspalatone>ticlopidine. Aspalatone, like acetylsalicylic acid, potently inhibited only the secondary phase of ADP-and epinephrine-induced aggregation. Thromboxane $B^2$ production evoked by collagen in human PRP was inhibited significantly and concentration-dependently by aspalatone and acetylsalicylic acid. These results were in agreement with the earlier studies in which the antiplatelet action of aspalatone was indicated to be due to the inhibition of platelet cyclooxygenase activity (Han et al., Arzneim. Forsch./Drug Res. 44(II), 1122, 1994; Suh and Han, Yakhak Hoeji 39, 565, 1995). In addition, the inhibitory activity of aspalatone on the platelet aggregation appears to be inversely related to the rate of nonspecific deacetylation of the drug in plasma.

• Journal of Chest Surgery
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• v.33 no.3
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• pp.221-229
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• 2000

Background: Thromboxane A2 and endothelin-1 are the potent vasoconstrictors affecting pulmonary pathophysiology in response to whole body inflammatin following CPB. Aprotinin, as an antiiflammatory agent, may decrease the release of such vasoactive substance from pulmonary tissues, preventing pulmonary hypertension after cardiopulmonary bypass. Material and Method: Ten mongrel dogs(Bwt. ac. 20kg) were subjected to cardioupulmonary bypass for 2 hours and postbypass pulmonary vascular resistance(0, 1, 2, 3 hours) were compared with prebypass level. The dogs were divided into 2 groups; control group(n-5) and aprotinin group(n=5). In the aprotinin group, aprotinin was administered as follows; 50,000 KIU/kg mixed in pump priming solution, 50,000 KIU/kg prebypass intravenous infusion over 30 minutes, 10,000 KIU/kg/hour postbypass continuous infusion. Prebypass and postbypass 0, 1, 2, 3 hour pulmonary vascular resistance were measured. At prebypass and postbypass 0, 90, 180 minutes, blood samples were obtained from pulmonary arterial and left atrial catherers for the assay of plasma thromboxane B2 a stable metabolite of thromboxane A2, and endothelin-1 concentrations. Result: The ratios of pustbypass over prebypass pulmonary vascular at postbypass 0, 1, 2, 3 hours were 1.28$\pm$0.20, 1.82$\pm$0.23, 1.90$\pm$0.19, 2.14$\pm$0.18 in control group, 1.58$\pm$0.18, 1.73$\pm$0.01, 1.66$\pm$0.10, 1.50$\pm$0.08 in aprotinin group ; the ratios gradually increased in control group while decreased or fluctuated after postbypass 1 hour in aprotinin group. There was statistically significant difference between control group and aprotinin group at postbypass 3 hours(P=0.014). Pulmonary arterial plasma concentration of thromboxane B2(pg/ml) at prebypass, postbypass 0, 90, 180 minutes were 346.4$\pm$61.9, 529.3$\pm$197.6, 578.3$\pm$255.8, 493.3$\pm$171.3 in control group, 323.8$\pm$118.0, 422.6$\pm$75.6, 412.3$\pm$59.9, 394.5$\pm$154.0 in aprotinin group. Left atrial concentrations were 339.3$\pm$89.2, 667.0$\pm$65.7, 731.2$\pm$192.7, 607.5$\pm$165.9 in control group, 330.0$\pm$111.2, 468.4$\pm$190.3, 425.4$\pm$193.6, 4.7.3$\pm$142.8 in aprotinin group. These results showed decrement of pulmonary thromboxane A2 generation in aprotinin group. Pulmonary arterial concentrations of endothelin-1(fmol/ml) at the same time sequence were 7.84$\pm$0.31, 13.2$\pm$0.51, 15.0$\pm$1.22, 16.3$\pm$1.73 in control group, 7.76$\pm$0.12, 15.3$\pm$0.71, 22.6$\pm$6.62, 14.9$\pm$1.11 in aprotinin group. Left atrial concentrations were 7.61$\pm$17.2, 57.1$\pm$28.4, 18.9$\pm$18.2, 31.5$\pm$20.5 in control group, 5.61$\pm$7.61, 37.0$\pm$26.2, 28.6$\pm$21.7, 37.8$\pm$30.6 in aprotinin group. These results showed that aprotinin had no effect on plasma endothelin-1 concentration after cardiopulmonary bypass. Conclusion: Administration of aprotinin during cardiopulmonary bypass could attenuate the increase in pulmonary vascular resistance after bypass. Inhibition of pulmonary thromboxane A2 generation was thought to be one of the mechanism of this effect. Aprotinin had no effect on postbypass endothelin-1 concentration.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2009.10a
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• pp.204-204
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• 2009

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.139-147
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• 2011

Objectives : The aim of this study is to research an anti-thrombus effect by Diospyros Kaki Calyx. Methods : The healthy human plasma were gained and used in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups ; intact control group (orally administrated with distilled water 5ml/kg) and two experimental group treated with extract of diospyros kaki calyx (EKC). Experimental rats were orally 600 mg/kg concentration of EKC and 200 mg/kg concentration of EKC. After an hour from administration, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weight of thrombus, took whole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, EKC significantly increased inhibitory activity of FXa, prothrombinase compared with intact control group ($^*P$ <0.05). PT and aPTT were increased in EKC treated (600 mg/kg) group compared with intact control group ($^*P$ <0.05). In vivo, blood clotting time of experiment group treated with EKC 600 mg/kg were significantly increased compare with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with EKC 600 mg/kg in serum. The weight of thrombus were significantly reduced in group treated with EKC 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those parameters of group treated with EKC 200 mg/kg were relatively decreased compared with those of intact control group without statistical significance. Conclusions : EKC has an antithrombic activity because of inhibition internal course such as FXa and prothrombin. And EKC inhibited a hole blood clotting in vivo experiment by low content of thromboxane B2.