• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.187-202
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• 1989

This study was undertaken to investigate the effect of indomethacin on prostaglandins in 4-Nitroquinoline-N-Oxide (4-NQO) induced palatal carcinoma of albino rats. 128 Sprague-Dawley strain albino rats-about 100g in body weight-were used in this study, divided into as belows; 1. Normal group (16-albino rats) with no treatment, 2. Control group (16-albino rats) treated with prophylene application onto palatal mucosa 3 times a week. 3. Experimental group I (48-albino rats) treated with 0.5% 4-NQO in prophylene application onto palatal mucosa 3 times a week. 4. Experimental group II (48-albino rats) treated with 0.5% 4-NQO in prophylene application with administered $20{\mu}g/ml$ of indomethacin in drinking water ad. lib. Four animals were sacrificed 7th, 13th, 19th, and 25th week respectively in normal and control group, and 7th, 9th, 11th, 13th, 15th, 17th, 19th, 21st, 23rd, 25th, 27th and 29th week respectively in experimental group I and II at each time. The palatal and lingual tissues were excised and kept frozen at $-70^{\circ}C$. Densitometer scan and Beta-counting counter were used for the thin layer chromatography of the arachidonic acid metabolites. The obtained results were as belows; 1. In normal and control group, there was little change of the arachidonic acid metabolites during experiment period, and the tissue homogenates included prostaglandin $D_2$, 6-keto-prostaglandin $F_{1{\alpha}}$, prostaglandin $E_2$, thromboxane $B_2$, prostaglandin $F_{2{\alpha}}$ in that order of relative abundances. 2. In experimental group I, prostaglandin $D_2$, and prostaglandin $E_2$ were increased, while 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$ were decreased in relative abundances of arachidonic acid metabolites. And there was little change in prostaglandin $F_{1{\alpha}}$ 3. In experimental group II, prostaglandin $D_2$, and prostaglandin $E_2$ were increased, while 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$ were decreased in relative abundances of arachidonic acid metabolites. And there was little change in prostaglandin $F_{2{\alpha}}$ also. 4. In the range of increase in prostaglandin $D_2$, and prostaglandin $E_2$, and that of decrease in 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$, in relative abundances, there was wider in experimental group I than in group II. 5. In the range of increase in prostaglandin $D_2$, and prostaglandin $E_2$, and that of decrease in 6-keto-prostaglandin $F_{1{\alpha}}$ and thromboxane $B_2$, in relative abundances, there was wider in palatal mucosa than in lingual mucosa in experimental group I and II.

• Journal of Integrative Natural Science
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• v.8 no.1
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• pp.75-79
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• 2015

Thromboxane A2 receptors (TXA2-R) are the G protein coupled receptors localized on cell membranes and intracellular structures and play pathophysiological role in various thrombosis/hemostasis, modulation of the immune response, acute myocardial infarction, inflammatory lung disease, hypertension and nephrotic disease. TXA2 receptor antagonists have been evaluated as potential therapeutic agents for asthma, thrombosis and hypertension. The role of TXA2 in wide spectrum of diseases makes this as an important drug target. Hence in the present study, homology modeling of TXA2 receptor was performed using the crystal structure of squid rhodopsin and night blindness causing G90D rhodopsin. 20 models were generated using single and multiple templates based approaches and the best model was selected based on the validation result. We found that multiple template based approach have given better accuracy. The generated structures can be used in future for further binding site and docking analysis.

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.72-77
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• 2008

The present study was undertaken to determine whether pioglitazone treatment 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. Pioglitazone decreased Rho-kinase activating agonist-induced contraction but not phorbol ester-induced contraction suggesting the least involvement of $Ca^{2+}$-independent thin filament regulation of contractility. Furthermore, pioglitazone decreased thromboxane $A_2$ mimeticinduced phosphorylation of MYPT1 at Thr855, the newly-highlighted site, instead of Thr696. In conclusion, this study provides the evidence and possible related mechanism concerning the vasorelaxing effect of pioglitazone as an antihypertensive on the agonist-induced contraction in rat aortic rings regardless of endothelial function.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.298-304
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• 1997

Molecular mechanics and conformation search methods were carried oyt to investigate the relationship between conformations and thromboxane synthetase ingibitory activities of om ega-pyridylalkenoic acids. The initial geometries of ${\omega}$-pyridylalkenoic acids and heme part of cytochrome P-450 were obtained from MM+ geometry optimization. The bond lenths and angles were not varied by step during the conformation searching. Stable conformers of some ${\omega}$-pyridylalkenoic acids were obtained by comformational search method. The distances were 8.5~10.8 ${\AA}$- between N atom at 3-position of pyridine ring and C atom at carboxylic group of stable ${\omega}$-pyridylalkenoic acids. The conformations of ${\omega}$-pyridylalkenoic acids and heme part complex were determined by same method. In theses structures, benzene ring and ethylene group in ${\omega}$-pyridylalkenoic acids are making the structure more rigid and increase inhbitory activity. The electron donating groups in C atom shich is connected to pyridine ring also increase activity.

• YAKHAK HOEJI
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• v.56 no.3
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• pp.180-185
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• 2012

The aim of present study was to investigate the possible influence and related mechanism of alcohol on the arterial contraction. Vascular contraction involves the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in alcohol-induced regulation. We hypothesized that alcohol plays a role in vascular contraction evoked by a vasoconstrictor in rat aortae regardless of endothelial function. Denuded arterial rings from male rats were used and isometric contractions were recorded using a computerized data acquisition system. Interestingly, alcohol at a low concentration (3% v/v) inhibited thromboxane $A_2$ or phorbol ester-induced contraction with endothelial function but at a high concentration (10%) didn't inhibit and rather increased the contraction in the denuded muscle. Therefore, alcohol at a low concentration decreases the contraction and alcohol at a high concentration increases the contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the regulation of contractility. In conclusion, alcohol has some effect on the regulation of contractility regardless of endothelial function.

• YAKHAK HOEJI
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• v.58 no.5
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• pp.337-342
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• 2014

The present study was undertaken to investigate the influence of diosgenin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that diosgenin, the primary ingredient of Dioscorea villosa, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, diosgenin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis such as inhibition of Rho-kinase might be involved in the vasorelaxation. Furthermore, diosgenin didn't inhibit thromboxane $A_2$-induced increases in pERK1/2 levels suggesting the mechanism excluding inhibition of thromboxane $A_2$-induced increases in ERK1/2 phosphorylation. This study provides evidence that diosgenin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.231-237
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• 2020

Euchrestaflavanone B (EFB) is a flavonoid that can be found in root bark, particularly in Cudrania tricuspidata (C. tricuspidata). The extract of C. tricuspidata is widespread throughout Asia and used in traditional medicine. In a previous study, we found anti-platelet effects of substances isolated from C. tricuspidata on collagen-induced human platelets. However, the C. tricuspidata still contains numerous substances, thus, we have searched new candidate, EFB isolated from C. tricuspidata for anti-platelet effect. Our results showed that EFA inhibited collagen-induced platelet aggregation and glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production and clot retraction. These results suggest that EFA has inhibitory effects on human platelet activities and thrombus formation and has potential value as a natural substance for preventing platelet-induced thrombosis.

• Proceedings of the Korean Nutrition Society Conference
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• 1997.11b
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• pp.42-42
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• 1997

• Proceedings of the Korean Nutrition Society Conference
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• 1996.11b
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• pp.56-56
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• 1996

• The Korean Journal of Pharmacology
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• v.20 no.1 s.34
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• pp.41-46
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• 1984

Cadmium (Cd) was administered by a series of weekly intraperitoneal injections at dose of 2mg/kg in rabbits and rats. The levels of malondialdehyde (MDA) and thromboxane $B^2(TXB_2)$ in platelet-rich plasma from Cd-poisoned animals were significantly higher than those of the control group. Furthermore, the inhibition of 6-keto-prostaglandin $F_{1{\alpha}}$, production in Cd-treated aorta ring was inversely related to the enhancement of platelet aggregation. These results suggest that Cd not only inhibits prostacyclin synthesis in the arterial endothelium, but also stimulates the platelet aggregation by enhancing thromboxane AZ production. These findings are assumed to support the evidence of an effect of Cd toxicity on the vascular wall and platelet function in raising arteriall pressure.