• Title/Summary/Keyword: smooth muscle relaxation

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Ethanol Extract of Cynanchum wilfordii Produces Endothelium-Dependent Relaxation in Rat Aorta and Anti-inflammatory Activity in Human Aortic Smooth Muscle Cells

  • Choi, Deok-Ho;Lee, Yun-Jung;Kim, Eun-Joo;Li, Xiang;Kim, Hye-Yoom;Hwang, Sun-Mi;Yoon, Jung-Joo;Lee, So-Min;Min, Eun-Kyeong;Kang, Dae-Gill;Lee, Ho-Sub
    • The Journal of Korean Medicine
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    • v.31 no.6
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    • pp.47-57
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    • 2010
  • Objective: The present study investigated the effect of ethanol extract of Cynanchum wilfordii (ECW) on vascular relaxation and vascular inflammation in rat artery isolated from rats and anti-inflammatory activity in human aortic smooth muscle cells (HASMC). Methods: Vascular tone and guanosine 3',5'-cyclic monophosphate (cGMP) production were examined in rat artery isolated from Sprague Dawley rats, in the presence of ECW. HASMC were incubated with tumor necrosis factor-alpha (TNF-${\alpha}$) or Angiotensin II for 24 h. Matrix metalloproteinase (MMP)-2 and anti-oxidant activity of ECW was investigated by pretreatment with ECW in HASMC. Results: Cumulative treatment of ECW relaxed aortic smooth muscles of rats in a dose-dependent manner. ECW-induced vasorelaxation was significantly decreased by pretreatment of L-arginine methyl ester (L-NAME) or oxadiazolo-quinoxalinone (ODQ). Furthermore, ECW treatment of thoracic aorta significantly increased cGMP production. Incubation of ECW with ODQ or L-NAME markedly decreased ECW-induced cGMP production. ECW treatment dose-dependently suppressed TNF-${\alpha}$- or Angiotensin II-induced increase in matrix metalloproteinase-2 expression in HASMC. Also, ECW exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity in vitro and reduced TNF-${\alpha}$-induced increase in reactive oxygen species production in a dose-dependent manner. Conclusions: Taken together, the results suggest that ECW exerts vascular relaxation via NO/cGMP signaling pathway and decreases MMP-2 expression via anti-oxidant activity.

The Effect of Carbon Monoxide on Contraction, Cytosolic $Ca^{2+}$ Level and Ionic Currents in Guinea Pig Ileal Smooth Muscle

  • Kwon, Seong-Chun;Chung, Seung-Soo;Kim, Yun-Suk;Nam, Taick-Sang
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.6
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    • pp.479-486
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    • 2000
  • The aim of this study was to clarify the mechanism of the inhibitory action of carbon monoxide (CO) on contraction, by measuring cytosolic $Ca^{2+}$ level $([Ca^{2+}]_i)$ and ionic currents in guinea-pig ileum. CO (10%) inhibited 40 mM KCl-induced contraction and this effect was blocked by ODQ $(1\;{\mu}M),$ a soluble guanylyl cyclase (sGC) inhibitor. CO inhibited the 40 mM KCl-induced contraction without changing $[Ca^{2+}]_i.$ Cumulative addition of KCl induced a graded increase in $[Ca^{2+}]_i$ and muscle tension. In the presence of CO, cumulative addition of KCl induced smaller contraction than in the absence of CO. On the other hand, the increase in $[Ca^{2+}]_i$ induced by cumulative addition of KCl was only slightly decreased in the presence of CO, and the $[Ca^{2+}]_i-tension$ relationship shifted downwards. Using the patch clamp technique with a holding potential of -60 mV, we found that CO had little effect on the peak Ba currents $(I_{Ba})$ when voltage was stepped from -60 mV to 0 mV. In addition, CO showed no effect on the depolarization-activated outward $K^+$ currents in the all potential ranges. We conclude that CO inhibits smooth muscle contraction mainly by decreasing the $Ca^{2+}$ sensitivity of contractile elements via a cGMP-dependent pathway, not by involving L-type $Ca^{2+}$ and outward-potassium currents in guinea-pig ileum.

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A Cohen syndrome patient whose muscle-relaxant effect may have been prolonged during general anesthesia: a case report

  • Ishikawa, Emi;Shibuya, Makiko;Kimura, Yukifumi;Kamekura, Nobuhito;Fujisawa, Toshiaki
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.22 no.2
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    • pp.155-159
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    • 2022
  • Cohen syndrome is a rare genetic disorder associated with mutations in the VPS13B gene. Individuals with this disorder present with diverse clinical manifestations, including muscle hypotonia, intellectual disabilities, and typical facial characteristics, such as prominent upper central incisors and micrognathia. General anesthesia was administered to a 23-year-old man with Cohen syndrome. Although we observed prominent upper central incisors, an overjet of 10 mm, micrognathia, and thyromental distance of 4 cm, hypotonia was not observed in the patient. Intubation was rendered difficult when performing a direct laryngoscopy. However, smooth intubation was achieved using a video laryngoscope. The patient's train of four (TOF) count remained zero close to 60 min after rocuronium administration, suggesting that the drug's muscle-relaxant effect may have been prolonged. A TOF ratio of 0.79 was confirmed 130 min after rocuronium administration, and a TOF ratio of 1.0 was confirmed after administration of 150 mg of sugammadex. The patient's respiration remained stable after extubation, and no recurarization of muscle relaxation was observed. As demonstrated in this case report, it is important to closely monitor recovery from muscle relaxation and prepare multiple techniques for airway management in general anesthesia management of patients with Cohen syndrome.

Ginsenosides Evoke Vasorelaxation in Rat Aortic Rings: Involvement of $Ca^{2+}$-dependent $K^+$ Channels

  • Nak Doo Kim;Soo
    • Proceedings of the Ginseng society Conference
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    • 1998.06a
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    • pp.182-189
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    • 1998
  • Administration of ginsenosides, a mixture of saponin extracted from Panax ginseng, decreased blood pressure in rat. Previous studies have shown that ginsenosides caused endothelium-dependent relaxation, which was associated with the formation of cyclic GMP, suggested that ginsenosides caused release of nitric oxide (NO) from the vascular endothelium. The aim of the present study was to characterize the endothelium-independent relaxation to ginsenosides in the isolated rat aorta. Ginsenosides caused a concentration-dependent relaxation of rat aortic rings without endothelium constricted with 25 mM KCI but affected only minimally those constricted with 60 mM KCI. Ginsenoside Rg3 (Rg3) was a more potent vasorelaxing agonist than total ginsenoside mixture and also the ginsenoside PPT and PPD groups. Relaxation to ginsenosides were markedly reduced by TEA, but not by glibenclamide. Rg3 significantly inhibited Cal'-induced concentration-contraction curves and the "50a2'influx in aortic rings incubated in 25 mM KCI whereas those responses were not affected in 60 mM KCI. Rg3 caused efflux of $"Rb in aortic rings that was inhibited by tetraethy- lammonium (TEA), an inhibitor of Ca"-dependent K'channels, but not by glibenclamide, an inhibitor of AfP-dependent K'channels. These findings indicate that ginsenosides may induce vasorelaxation via activation of Ca2'-dependent K'channels resulting in hyperpolarization of the vas- cular smooth muscle with subsequent inhibition of the opening of voltage-dependent Caf'channels. These effects could contribute to explain the red ginseng-associated vasodilation and the beneficial effect on the cardiovascular system.

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Inhibitory Effect of Genistein on Agonist-Induced Modulation of Vascular Contractility

  • Je, Hyun Dong;Sohn, Uy Dong
    • 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.

The Inhibitory Effect of Broccoli in Cruciferous Vegetables Derived-Sulforaphane on Vascular Tension (브로콜리 유래 Sulforaphane의 혈관 수축성 조절 효과)

  • Je, Hyun Dong
    • 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.

Effect of Curcuma Longa Derived-curcumin on Vascular Tension (강황 유래 Curcumin의 Rho-kinase 억제를 통한 혈관이완작용)

  • Je, Hyun Dong
    • YAKHAK HOEJI
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    • v.57 no.5
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    • pp.376-381
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    • 2013
  • The present study was undertaken to investigate the influence of curcumin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that curcumin, the primary ingredient of Curcuma longa, 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, curcumin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the vasorelaxation. Furthermore, curcumin significantly inhibited fluoride-induced increases in pMYPT1 levels. On the other hand, it didn't significantly inhibit phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving inhibition of fluoride-induced MYPT1 phosphorylation. This study provides evidence that curcumin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

The Effect of Dioscorea villosa Derived-diosgenin on Vascular Contractility (참마 유래 Diosgenin의 혈관 수축성 조절 효과)

  • Je, Hyun Dong
    • 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.

Effect of Acorus Gramineus on the Relaxation of Corpus Cavernosum Smooth Muscle (석창포에 의한 발기부전 개선 효과)

  • Li, Xiang;Kim, Ho-Tae;Lee, Jae-Yun;Lee, Yun-Jung;Shin, Hong-Kyun;Kang, Dae-Gill;Lee, Ho-Sub
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.5
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    • pp.863-869
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    • 2011
  • The aim of the present study is to investigate whether an ethanol extract of Acorus gramineus Soland (EAG) augments penile erection in vitro and in vivo experiment. Preconstructed with phenylephrine (PE) in isolated endothelium-intact rabbit corpus cavernosum, EAG relaxed penile smooth muscle in a dose-dependent manner, which was inhibited by pretreatment with NG-nitro-L-argininemethylester (L-NAME), a nitricoxide synthase inhibitor, and 1H-[1,2,4]-oxadiazole-[4,3-${\alpha}$]-quinoxalin-1-one (ODQ), a soluble guanylylcyclase (sGC) inhibitor, respectively. EAG-induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA), a nonselective $K^+$ channel blocker. EAG increased cGMP levels of the rabbit corpus cavernosum in a concentration-dependent manner without changes in cAMP levels. In addition, EAG caused increase of peak intracavernous pressure (ICP), ICP/MAP ratio and area under the carve (AUC) in SD rats. Taken together, these results suggest that EAG augments penile erection via NO-cGMP system and $K^+$ channels in corpus cavernosum.