• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.155-155
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• 2002

Several epidemiological studies have suggested that exposure to arsenic is strongly correlated with the development of cardiovascular diseases such as hypertension. To determine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on vasorelaxation using isolated rat aortic rings in an organ bath system.(omitted)

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.71-71
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• 2003

Several epidemiological studies suggested that arsenic exposure was strongly correlated with the development of cardiovascular disease such as hypertension. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation using the isolated rat aortic rings in in vitro organ bath system. (omitted)

• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.257-265
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• 2018

The Panax ginseng Mayer is used in conventional medicine in Asia owing to its preventing effects on thrombosis, hypertension, atherosclerosis, vasorelaxation and myocardial infarction. Because platelets are crucial mediators of cardiovascular diseases, many studies have investigated its functions. The previous study showed the antiplatelet effects of crude ginseng fraction and two of its components, ginsenoside Rg3 (20S and 20R). In addition, ginsenoside Rg3-enriched fraction shows an inhibitory effect on collagen-activated rat platelets. However, the mechanism underlying this effect remains unclear. Thus, I investigated the inhibitory action of ginsenoside Rg3 (20S, G-Rg3) on the regulation of signaling molecules involved in ${\alpha}IIb/{\beta}_3$ activation. I found that G-Rg3, in a cyclic AMP dependent manner, inhibited thrombin-induced activation of human platelets and affinity of fibrinogen and fibronectin with ${\alpha}IIb/{\beta}_3$. Thus, in the present study, G-Rg3 showed an inhibitory effect on glycoprotein IIb/IIIa (${\alpha}IIb/{\beta}_3$) activation, suggesting its potential use for preventing platelet-mediated thrombotic disease.

• Journal of Pharmacopuncture
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• v.19 no.2
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• pp.145-154
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• 2016

Objectives: The aim of this paper is to investigate the activities of Malaysian local herbs (Clinacanthus nutans Lindau, Strobilanthes crispus, Murdannia bracteata, Elephantopus scaber Linn., Pereskia bleo, Pereskia grandifolia Haw., Vernonia amygdalina, and Swietenia macrophylla King) for anti-hypertensive and vasorelaxant activity. An infrared (IR) macro-fingerprinting technique consisting of conventional fourier transform IR (FTIR), second-derivative IR (SD-IR), and two-dimensional correlation IR (2D-correlation IR) analyses were used to determine the main constituents and the fingerprints of the Malaysian local herbs. Methods: The herbs were collected, ground into powder form, and then macerated by using three different solvents: distilled water, 50% ethanol, and 95% ethanol, respectively. The potentials of the extracts produced from these herbs for use as vasorelaxants were determined. Additionally, the fingerprints of these herbs were analyzed by using FTIR spectra, SD-IR spectra, and 2D-correlation IR spectra in order to identify their main constituents and to provide useful information for future pharmacodynamics studies. Results: Swietenia macrophylla King has the highest potential in terms of vasorelaxant activity, followed by Vernonia amygdalina, Pereskia bleo, Strobilanthes crispus, Elephantopus scaber Linn., Pereskia grandifolia Haw., Clinacanthus nutans Lindau, and Murdannia bracteata. The tri-step IR macro-fingerprint of the herbs revealed that most of them contained proteins. Pereskia bleo and Pereskia grandifolia Haw. were found to contain calcium oxalate while Swietenia macrophylla King was found to contain large amounts of flavonoids. Conclusion: The flavonoid content of the herbs affects their vasorelaxant activity, and the tri-step IR macro-fingerprint method can be used as an analytical tool to determine the activity of a herbal medicine in terms of its vasorelaxant effect.

• Journal of Physiology & Pathology in Korean Medicine
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• v.33 no.4
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• pp.198-206
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• 2019

This study was conducted to evaluate the vasorelaxant effect of DangGuiSu-San and SamHwangSaSim-Tang extract on contracted rabbit carotid artery. To study the effect of DangGuiSu-San and SamHwangSaSim-Tang extract on contracted rabbit carotid arterial strips, arterial strips with intact or damaged endothelium were used for experiment using organ bath. The pre-contracted arterial strips with Phenylephrine(PE) was treated with various concentrations of DangGuiSu-San and SamHwangSaSim-Tang extract(0.01, 0.03, 0.1, 0.3 and $1.0mg/m{\ell}$). To determine the mechanisms of DangGuiSu-San and SamHwangSaSim-Tang-induced vasorelaxant, DangGuiSu-San and SamHwangSaSim-Tang extract were infused into contracted arterial rings which had been pretreated by indomethacin(IM), tetraethylammonium chloride(TEA), $N{\omega}$-nitro-L-arginine ($_L-NNA$), methylene blue(MB). And calcium chloride(Ca) 1 mM was infused into precontracted arterial ring induced by PE after treatment of DangGuiSu-San and SamHwangSaSim-Tang extract in $Ca^{2+}$-free krebs solution. DangGuiSu-San and SamHwangSaSim-Tang extract revealed significant relaxation on PE-induced arterial contraction. DangGuiSu-San and SamHwangSaSim-Tang extract also had an effective relaxation to the intact endothelium arterial ring. SamHwangSaSim-Tang extract on contracted rabbit carotid artery is related with NO-cGMP pathway. Pretreatment of DangGuiSu-San and SamHwangSaSim-Tang extract inhibited the contraction by influx of extracellular $Ca^{2+}$ in contracted arterial ring induced by NE. This study indicated that the relaxation effect of SamHwangSaSim-Tang extract on contracted rabbit carotid artery is related with NO-cGMP pathway. Pretreatment of DangGuiSu-San and SamHwangSaSim-Tang extract inhibited the contraction by influx of extracellular $Ca^{2+}$ in contracted arterial ring induced by NE.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.1
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• pp.27-34
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• 1997

In the present study, it was aimed to further indentify the intracellular action mechansm of cromakalim and levcromakalim in the porcine coronary artery. In intact porcine coronary arterial strips loaded with fura-2/AM, acetylcholine caused an increase in intracellular free $Ca^{2+}$ $([Ca^{2+}]_i)$ in association with a contraction in a concentration-dependent manner. Cromakalim (1 ${\mu}M$) caused a reduction in acetylcholine-induced increased $[Ca^{2+}]_i$ not only in the mormal physiological salt solution (PSS) but also in $Ca^{2+}$-free PSS (containing 1 mM EGTA). In the skinned strips prepared by exposure of tissue to 20 .${\mu}M$ B-escin, inositol 1,4,5-trisphosphate ($IP_3$) evoked an increase in $[Ca^{2+}]_i$, but it was without effect on the intact strips. The $IP_3$-induced increase in $[Ca^{2+}]_i$ was inhibited by cromakalim by 78% and levcromakalim by 59% (1 .${\mu}M$, each). Pretreatment with glibenclamide (a blocker of ATP-sensitive $K^+$ channels, 10 .${\mu}M$) and apamin (a blocker of small conductance $Ca^{2+}$-activated $K^+$ channels, 1 .${\mu}M$) strongly blocked the effect of cromakalim and levcromakalim. However, charybdotoxin (a blocker of large conductance $Ca^{2+}$-activated $K^+$ channels, 1 .${\mu}M$) was without effect. In addition, cromakalim inhibited the $GTP{\gamma}S$ (100 .${\mu}M$, non-hydrolysable analogue of GTP)-induced increase in $[Ca^{2+}]_i$. Based on these results, it is suggested that cromakalim and levcromakalim exert a potent vasorelaxation, in part, by acting on the $K^+$ channels of the intracellular sites (e.g., sarcoplasmic reticulum membrane), thereby, resulting in decrease in release of $Ca^{2+}$ from the intracellular storage site.

• 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.

• 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.

• Toxicological Research
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• v.28 no.4
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• pp.249-253
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• 2012

In this study, we prepared alcohol extracts of the larva, pupa, queen, and cocoon (clony) of B. ignitus, B. terrestris, and B. h. sapporoensis, and tested the anti-inflammatory activity of the extracts by using a rat model of adjuvant-induced edema. The extracts derived from the queen of B. ignitus, the queen of B. terrestris, and the cocoon of B. ignitus decreased hind paw edema after 1 day of i.p. administration. These extracts also induced vasorelaxation and NO production in calf pulmonary artery endothelial cells. These results suggest that bumblebee alcohol extracts has anti-inflammatory and vasorelaxant properties.

• 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.