• Title/Summary/Keyword: Endothelium-independent relaxation

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Endothelium-Independent Effect of Fisetin on the Agonist-Induced Regulation of Vascular Contractility

  • Je, Hyun Dong;Sohn, Uy Dong;La, Hyen-Oh
    • Biomolecules & Therapeutics
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    • v.24 no.1
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    • pp.57-61
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    • 2016
  • Fisetin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of fisetin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Fisetin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, fisetin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of fisetin on agonist-induced vascular contraction regardless of endothelial function.

Effect of Samhwangsasim-tang, Samigangap-tang and Bangtan-tang on Blood Pressure in Stroke Prone Spontaneously Hypertensive Rats (뇌졸중성(腦卒中性) 본태성(本態性) 고혈압(高血壓) 백서(白鼠) 모델에서 삼황사심탕(三黃瀉心湯), 사미강압탕(四味降壓湯), 방탄탕(防癱湯)의 혈압(血壓)에 미치는 영향(影響))

  • Kim, Eun-Ju;Kim, Hye-Yoom;Lee, Jae-Yun;Lee, Jun-Kyoung;Kim, Seung-Ju;Choi, Kyoung-Min;Kang, Dae-Gill
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.75-80
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    • 2011
  • Objectives : The aim of the present study is to investigate the hypotensive effect of Samhwangsasim-tang (SHSST), Samigangap-tang (SMGAT) and Bangtan-tang (BTT) in stroke-prone spontaneously hypertensive rats (SHR-SP). Methods : SHR-SP rats were treated with SHSST, SMGAT and BTT at dose of 200 mg/kg/day orally for 5 weeks, respectively. Results : Treatment SHR-SP rats with SMGAT significantly lowered blood pressure but not in the SHSST or BTT treat groups. On the other hand, SHSST, SMGAT and BTT ameliorated endothelium-dependent and independent vascular relaxation in the phenylephrine-precontracted aorta and carotid artery, respectively. Conclusions : These results indicated that SMGAT has an antihypertensive effect and SHSST, SMGAT and BTT improve vascular function in stroke-prone hypertensive rat model, respectively.

Relaxant Actions of α2-Adrenoceptor Agonists in Rat Aorta (α2-Adrenoceptor Agonists의 흰쥐 대동맥 이완 작용)

  • Cho, In-gook;Lee, Sang-woo;Kang, Hyung-sub;Seo, Heyng-seok;Kim, Jin-shang
    • Korean Journal of Veterinary Research
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    • v.43 no.3
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    • pp.361-371
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    • 2003
  • The vasorelaxant actions and blood pressure lowering of the ${\alpha}_2$-adrenoceptor agonists (${\alpha}_2$-AAs) clonidine and xylazine were investigated in rat isolated aortic rings and anesthesized rats. Both clonidine and xylazine produced a concentration-dependent inhibition of the sustained contraction induced by norepinephrine (NE), but not by KCl. NE-induced contractions were attenuated partly by nifedipine or verapamil, voltage dependent $Ca^{2+}$ channel blockers. These $Ca^{2+}$ channel blockers-resistant contractions were abolished by clonidine or xylazine. Inhibitory effects of a ${\alpha}_2$-AAs on contractions could be reversed by ryanodine, an intracellular $Ca^{2+}$, transport blocker, and tetrabutylammonium (TBA), a $Ca^{2+}$ activated $K^+$ channel blocker, but not by nifedipine, glibenclamide or removal of extracellular $Ca^{2+}$ and endothelium. Moreover, ${\alpha}_2$-AAs produced relaxation in NE-precontracted isolated intact aortic rings in a concentration-dependent manner, but not in KCl-precontracted rings. The relaxant effects of ${\alpha}_2$-AAs were inhibited by ryanodine and TBA, but not by nifedipine, glibenclamide, N (G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME), aminoguanidine (AG), 2-nitro-4-carboxyphenyl N,N-diphenylcarhurnte (NCDC), lithium sulfate, staurosporine or removal of extracellular $Ca^{2+}$ and endothelium. In vivo, infusion of xylazine elicited significant decrease in anerial blood pressure. This xylazinelowered blood pressure was completely inhibited by the intravenous injection of TBA, but not by the intravenous injection of glibenclamide, L-NNA, L-NAME, AG, nifedipine, lithium sulfate or saponin.. These findings showed that the receptor-mediated and ${\alpha}_2$-adrenoceptor A-stimulated endothelium-independent vasorelaxant effect may be explained by decreasing intracellular $Ca^{2+}$ release and activation of $Ca^{2+}$-activated $K^+$ channels, which may contribute to the hypotensive effects of ${\alpha}_2$-AAs in rats.

Beneficial effects of Paeo-tang on cardiovascular and renal function in L-NAME-induced hypertensive rats (파어탕의 L-NAME 유도 고혈압 동물군에서의 혈압강하효과 및 심신기능 개선 효과)

  • Na, Se Won;Hong, Mi Hyeon;Kim, Hye Yoom;Jang, Youn Jae;Yoon, Jung Joo;Lee, Yun Jung;Kang, Dae Gill;Lee, Ho Sub
    • Herbal Formula Science
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    • v.28 no.3
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    • pp.271-280
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    • 2020
  • Hypertension has been approved to cause disharmony between the heart and kidney such as cardiac hypertrophy and kidney dysfunction. In traditional oriental medicine Paeo-tang (PET) has been shown to have effects on blood circulation improvement. However, the beneficial effect of PET on hypertension remains unknown. In this study, we investigated that PET attenuates blood pressure and improves cardiovascular and renal function in NG-nitro-L-arginine methylester (L-NAME) rat model. Hypertensive rat models were induced by the administration of L-NAME (40 mg/kg/day) and then PET (50 or 100 mg/kg/day) or Olmetec was treated for 2 weeks. PET treatment significantly suppressed the systolic blood pressure and decreased intima-media thickness in the thoracic aorta. PET ameliorated endothelium-dependent and independent vascular relaxation in the L-NAME-induced vascular dysfunction. PET ameliorated the functional decline in the kidney such as albumin and blood urea nitrogen in plasma. These results demonstrated that PET possesses protective effects against L-NAME-induced hypertension.

Effects of the Water Extracts of Mantidis Ootheca, Rosa Laevigata, and Imperata Cylindrica on Blood Pressure in Renovascular Hypertension Induced by 2K1C (상표초, 백모근, 금앵자 추출물이 2K1C 고혈압 백서의 혈압에 미치는 영향)

  • Kim, Hye Yoom;Ahn, You Mee;Kho, Min Chul;Park, Ji Hun;Lee, Jae Yun;Lee, Soo Ho;Park, Sueng Hyuk;Kim, Byung Sook;Kang, Dae Gill;Lee, Yun Jung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.2
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    • pp.95-100
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    • 2016
  • The aim of the present study is to investigate the hypotensive effect of Mantidis ootheca (WMO), Rosa laevigata (WIC), and Imperata cylindrica (WRL) in renovascular hypertension rats. Experimental hypertension model is 2-kidney and 1-clip (2K1C) induced rats. 2K1C rats were treated with WMO, WIC, and WRL at dose of 100 mg/kg/day orally for 3 weeks, respectively. Treatment groups with WMO, WIC, and WRL significantly lowered blood pressure. Interestingly, WMO, WIC, and WRL ameliorated endothelium-dependent and independent vascular relaxation in the phenylephrine-precontracted thoracic aorta in hypertension models. In addition, 2K1C-induced hypertension model increased plasma renin activity, however, WMO, WIC, and WRL attenuated those activities. These results suggest that WMO, WIC, and WRL ameliorates vascular dysfunction in 2K1C-induced hypertension models via the regulation of nitric oxide and renin-angiotensin-aldosterone system.