• Journal of Environmental Science International
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• v.12 no.10
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• pp.1131-1136
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• 2003

To examine whether salt stress would alter or not contractility of isolated rat aorta, under anesthesia with sodium pentobarbital(50 mg kg-1 i.p.), male Sprague Dawley rats(300-330 g) were subjected to 0, 50, and 150 mM of sodium chloride at 37$^{\circ}C$ for 60 min. where as the sham group was left at modified Krebs-bicarbonate solution. To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsp) by Western blotting. One, three and eight hours later, we measured vascular contractility of isolated rat aorta treated with KCI, phenylephrine from organ bath study. The dose-vascular responses of potassium chloride and phenylephrine showed a little augmentation by NaCl concentration in the strips exposed to NaCl for 8 hours. And the response of relaxation induced by nitroprusside and acetylcholine was not influenced by NaCl stress in isolated aorta ring for 8 hours, respectively. Expression pattern of Hsp 70 of vascular muscle in isolated rat aorta showed a little increase in 150 mM NaCl group at 8 hours after NaCl treatment but not at 3 hours, and Hsp 60 expression of rat aorta was markedly increased in 50 mM NaCl group at 8 hours after NaCl treatment. Taken together, NaCl induced dose-and time dependent accumulation of the Hsp but not affected contraction of rat aorta. These data suggest that short term high salt stress was not sufficient to induce hypertension of rat aorta.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1107-1110
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• 2004

The purpose of this research was to investigate the effects of supercritical fluid extract of Kamichungbieum (SFE) on the contraction of isolated rat aorta. The contractile force of rat aorta was measured with force displacement transducer under 1.5g loading tension. The contraction of aorta induced by phenylephrine 0.1 μM was inhibited by SFE. The aorta relaxed by SFE was inhibited by the pretreatment of L-NNA, ODQ or indomethacin, respectively. These results indicate that SFE induce the relaxation of isolated aorta via activation of nitric oxide, cAMP and cyclooxygenase in epithelium cells.

• The Korea Journal of Herbology
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• v.38 no.6
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• pp.53-60
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• 2023

Objectives : The objective of present study was to investigate the vasorelaxant effects of 10 traditional Korean Herbal Prescriptions (KHP) on isolated rat thoracic aorta precontracted with potassium chloride (KCl). Methods : An electric extractor was used to extract KHP in distilled water for 3h. Rat aorta rings were isolated and were precontracted using KCl in organ chambers containing 10 ml Krebs Henseleit (KH) buffer. KHP extracts were added in increasing concentrations (10-1000 ㎍/㎖) to investigate vasorelaxant effects. The vasorelaxant responses induced by KHP were expressed as a percentage in response to contraction generated by KCl. Results : Among the 10 KHP, Gamisoyo-san, Galgeun-tang, Gyeji-tang, Gwakhyangjeonggi-san, Daeyoung-jeon, and Socheongryong-tang showed significant vasorelaxant effect at high concentration. In contrast, Gyejibokryeong-hwan constricted more the aorta rings precontracted by KCl. And Gumiganghwal-tang, Guibi-tang, Saengmaek-san showed no significant effect. Also, rat aorta rings treated with Gyejibokryeong-hwan or Gyeji-tang after pre-relaxation by amlodipine did not cause any significant change. Conclusion : Thus, these results provide the experimental evidence as useful herbal prescriptions for the treatment of hypertension and suggest guidelines in conjunction with other western drugs, including amlodipine.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.88-88
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• 1995

Tetrahydroisoquinoline (THI) compounds have various pharmacological actions in the cardiovascular system. Recently, we have synthesized 1-${\alpha}$-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, YS 49. In the present study, we evaluated the effect of YS-49 on positive inotropic and chronotropic action using isolated rat heart and on blood pressure and heart rate using anesthesized rabbit. Vasodilating action was also assessed in isolated rat thoracic aorta. YS 49, concentration-dependently relaxed rat aorta precontracted with phenylephrine (PE, 0.3 ${\mu}$M) and high potassium (high K$\^$+/, 65.4 mM). The 50% inhibitory concentration (IC$\sub$50/) of YS 49 in PE-induced and high K$\^$+/-induded contraction was 5.36 ${\mu}$M and 2.52 ${\mu}$M, respectively. In isolated rat atria, YS 49 increased both heart rate and force, and in anesthesized rabbit it decreased blood pressure but increased heart rate. In addition, to know the mechanism of action of the compound, propranolol, nonselective ${\beta}$-antagonist, and phentolamine, ${\alpha}$-blocker, were used. Furthermore, a comparison with the effect of higenamine, trimetoquinol on the vasodilating action in rat thoracic aorta was also made. The action of YS 49 was inhibited by the presence of propranolo, not pentolamine. These results indicate that cardiotonic and vasodilatory action of YS 49 is attributable, at least in part, for ${\beta}$-receptor stimulation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.457-462
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• 2004

Bambusae Caulis in Liquamen has been used as a herbal medicine for the treatment of heat, paralysis of the hands or feet, or hemiplegia. In the present study, we investigated the effect of Bambusae Caulis in Liquamen to the phenylephrine (PE) induced contraction of isolated rat aorta Contractile force was measured with force displacement transducer under 1.5 g loading tension. Contractions evoked by PE 0.1 μM were significantly increased by low dosage of Bambusae Caulis in Liquamen, decreased by high dosage of Bambusae Caulis in Liquamen. L-NNA, ODQ and propranolol significantly altered the effect of Bambusae Caulis in Liquamen, but indomethacin did not change the relaxation of Bambusae Caulis in Liquamen. These results suggest that Bambusae Caulis in Liquamen can relax EP induced contraction of isolated rat aorta and that this decreasing contraction related to sympathetics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1299-1304
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• 2003

This study is to determine the effect of Fructus Rubi to the phenylehrine (PE) induced contraction of isolated rat aorta. Contractile force was measured with force displacement transducer under 1.5g loading tension. Contractions evoked by PE 0.1 μM and KCI 65.4 mM were decreased significantly by Fructus Rubi. L-NNA, ODQ, indomethacin and atropine significantly altered the effect of Fructus Rubi, but propranolol did not change the relaxation of Fructus Rubi. These results indicate that Fructus Rubi can relax EP and KCI induced contraction of isolated rat aorta and that this decreasing contraction related to epithelium, nitric oxide, and parasympathetics.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.203-203
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• 2002

Rheum palmatum L. has been used for treatment of hypertension, lipemia, and paramenia in the oriental gerbal medicines for a long time. We have examined the relaxational response to the water extract of Rheum palmaum L. in isolated thoracic aorta from sprague dawley (SD) rat in the presence and absence of endothelium. Rat thoracic aorta was investigated in vessel segments suspended for isometric tension recording by polygraph. Responses to Rhizoma Rhei were investigated in vessels precontracted with 5-hydroxytryptamine. We found that the ghoracic aorta segments responded to the water extract of Rheum palmatum L. (ERP) with a dose-dependent vasorelaxation. We found that 1.The thoracic aorta sehments responded to ERP with a dose-dependent vasodiliation. 2.The 5-HT induced contraction at 10$\^$-4/M were inhibited by 85.8% after addition of the 0.1 g/mL water extract of ERP. 3. The 5-HT induced contraction at 10$\^$-4/ M with and without endothelium were inhibited by 86.4% and 85.8% after addition of the 0.1g/mL ERP. 4. After pre-treatment of the thoracic aorta with 10$\^$-4/M N$\^$G/-monomethyl-L-arginine(L-NMMA), inducible niric oxide synthase inhibitor, the vessels has not response to the contraction. In conclusion, ERP induced reaxation in the isolated rat thoracic aorta were composed of dose-dependent relaxation. and it has potent vasodilation.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.651-657
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• 2003

In order to examine if arsenic, one of environmental stresses, contributes to hypertension as one of cardiovas cular pathological factors, this study was perfarmed in vivo and in vitro, using intacted or pithed rats and aorta ring preparation, respectively. And also the relationship between expression of heat shock protein (HSP) 90 and vasoactives-induced contractile response was elucidated. To measure blood pressure, the carotid arterial pressure was recorded on physiograph(Grass Co. 79E) connected to strain gauge. On the other hand, contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And HSP was detacted by Western blotting whole cell Iysis. Preganglionic nerve stimulation was increased by 26.0% in arterial pressure of rat treated with arsenic. Vascular contractile response was monitored and HSP were measured by Western blotting of whole Iysis prepared from samples exposed with 0, 0.5, 1, 2 and 4 mM of arsenic for 8 hours. The dose-vascular responses of potassium chloride were augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and were not augmented for 1, 3, 5 hours. And the response of relaxation of rat aorta induced by histamine was not influenced by arsenic stress. The increase of HSP 90 expression in rat aorta was pronounced at 8 hours after 4 mM of arsenic treatment, but HSP 60 expression was not. Arsenic stress not only increased the expression of HSP 90 in the rat aorta, but also augmented contractions to potassium chloride. These results indicated that arsenic stress was sufficient to induce heat shock protein 90, resulting in increased vascular contractility in rat aorta.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.515-522
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• 2004

The vasorelaxant effect of serotonin reuptake inhibitor fluoxetine was investigated in rat isolated thoracic aorta. Fluoxetine induced a concentration-dependent relaxation in aorta precontracted with phenylephrine (PE) and KCl. These relaxations were suppressed by removal of the endothelium (-E) or pretreatment of nitric oxide synthase inhibitors, N(G)-nitro-L-arginine (L-NNA) and N(omega)-nitro-Larginine methyl ester (L-NAME), guanylate cyclase inhibitors, methylene blue (MB) and 1H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ), and $Ca^{2+}$ channel blockers, nifedipine and verapamil, in PE-precontracted +E rings. However, fluoxetine-induced relaxations were not suppressed by pretreatment of $K^{+}$ channel blockers, tetrabutylammonium and glibenclamide, in PE-precontracted endothelium intact (+E) rings. The fluoxetine-induced relaxations were not suppressed by removal of the endothelium or pretreatment of LNNA and MB in KCl-precontracted +E rings. Also, fluoxetine inhibited PE-induced sustained contraction in +E rings. These inhibitory effects of fluoxetine on contractions could be reversed by removal of the endothelium or pretreatment of L-NNA, L-NAME, MB, ODQ, nifedipine and verapamil, but not by pretreatment of etrabutylammonium and glibenclamide. These findings suggest that the vasorelaxant effect of fluoxetine is modulated by intracellular $Ca^{2+}$ with an involvement of endothelial NO-cGMP pathway and also may be related to the inhibition of $Ca^{2+}$ entry through voltage-gated channel.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.119-124
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• 2001

In order to determine the role of dehydroepiandrosterone (DHEA), the important sex-steroid hormone precursor, in vascular reactivity in rats, animals were treated for two weeks with DHEA or sex hormones, and the vascorelaxant and contractile responses of isolated aorta were examined. DHEA diminished the acetylcholine (ACh)-induced relaxation in female rats, while the drug was without effect in males. Testoterone lowered the vasorelaxant activity to ACh in either sex. 17$\beta$-Estradiol enhanced ACh-induced vasorelaxation in male rats, but this female sex hormone did not influence in females. In male rats, the androgen receptor antagonist flutamide also enhanced vasorelaxant action of ACh. When the male rat aorta was incubated in vitro with a nitric oxide (NO) synthase inhibitor L-NAME, phenylephrine-induced contraction was greatly potentiated in DHEA-pretreated rats compared to control ones. The present results suggest that DHEA stimulates mainly androgen in female, but both androgen and estrogen in male rats. The participation of NO In the modulation of vascular reactivity with pretreated DHEA was also considered.