• 생약학회지
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• 제14권2호
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• pp.51-59
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• 1983

Experimental studies were made with Melilotus officinalis extract which was extracted from flowers and leaves of Melilotus officinalis Dsr. (Leguminosae). In this paper, acute toxicity, analgesic action, prolongation of hypnosis time by induced pentobarbital-Nain mice, antiinflammatory effect in rats and effects on isolated intestines of mice and rats were studied, The result was as follows; 1. Very low toxicity in mice. 2. Analgesic action was recognized markedly in mice. 3. Prolongation of hypnosis time induced by pentobarbital-Na in mice was shown. 4. Relaxing action was shown on the isolated ileum in mice and antagonistic action was seen on $BaCl_2-induced$ contraction of the ileum that the relaxing effect of the intestinal smooth muscle was recognized. 5.Antiinflammatory effect was shown markedly in mice. 6.Hypotensive and vaso-dilating actions due to the vascular smooth muscle relaxation were noted in rabbits.

• 생약학회지
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• 제18권4호
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• pp.241-248
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• 1987

Woohwangchungsim-Won has been widely used for the treatment of appoplexy, hypertension, arteriosclerosis, insomnia and cerebrovascular accident, etc in oriental hospital and pharmacy. In order to investigate the efficacy of Woohwangchungsim-Won, the water extract of it were bioassayed for isolated ileum, blood vessels, blood pressure, heart and diuresis. The results of this studies were as follows; Spontaneous motilities of isolated ileum of mice were strongly suppressed, and contraction of isolated ileum of mice and guinea-pigs induced by acetylcholine chloride, barium chloride and histamine were inhibited. Vaso-dilating action due to vascular smooth muscle relaxation in frogs and rabbits, and hypotensive action in anesthetized rabbits were noted. Negative inotropic action on the isolated frog heart and diuretic effect in rabbits were shown.

• 대한한방내과학회지
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• 제24권2호
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• pp.220-232
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• 2003

Objective : The purpose of this study was to analyze the effects of HwangRyunHaeDok-Tang and combinations of constituent herbs on the arterial contraction. Methods : In order to investigate the effects Scutellariae Radix. Coptidis Rhizoma, Phellodendri Cortex and Gardeniae Fructus, in which one of them, two of them, and all of them, were used to exam. Results : The results were summarized as follows; 1. HwangRyunHaeDok-Tang significantly inhibited the contraction of artery induced by Norepinephrine(NE). However the atonic effect was slightly blunted when the vascular endothelial cell was removed. No significant change in the atonic effect of HwangRyunHaeDok-Tang was found when $_L-NNA$ was used as a preliminary treatment. These results indicate that the vascular atonic effect by HwangRyunHaeDok-Tang is slightly dependent on the endothelial cell, and that the HwangRyunHaeDok-Tang works directly to the vascular smooth muscle in creating the vascular atonic effect. 2. The pretreatment of HwangRyunHaeDok-Tang extract significantly inhibited the contractile response to additive application of $Ca^{2+}$ in the strips which were contracted by NE in $Ca^{2+}$-free solution. 3. HwangRyunHaeDok-Tang extract increased the contraction of arterial smooth muscle induced by KCl. Therefore, it can be concluded that HwangRyunHaeDok-Tang may block the NE-receptor or receptor-operated $Ca^{2+}$ channel. 4. It was determined that Scutellariae Radix, Coptidis Rhizoma and Phellodendri Cortex among the ingredients of HwangRyunHaeDok-Tang have a vascular atonic effect. In addition, those ingredients plays a role in strengthening the atonic effect by working with other herbal medicines. Gardeniae Fructus causes the blood vessel to contract. but it does not influence the atonic effects of other herbal medicines. However Gardeniae Fructus tends to inhibit the vascular atonic effect of Phellodendri Cortex. Conclusion : Based on the above results, it can be said that HwangRyunHaeDok-Tang can be applied to cure hypertension considering those three herbs have significant effects of relaxation.

• The Korean Journal of Physiology
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• 제29권1호
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• pp.39-50
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• 1995

This study was designed to clarify the action of cyclic nucleotides, cyclic AMP and cyclic GMP, on phorbol 12,13-dibutyrate (PDBu)-induced contraction in rings isolated from rabbit carotid artery. Arterial rings, 2 mm in width, were myographied isometrically in an isolated organ bath. PDBu produced slowly developing, sustained contraction in rabbit carotid artery, in a dose dependent manner, which was independent of extracellular $Ca^{2+}$ PDBu-induced contraction was relaxed by staurosporine, which suggests that PDBu-induced contraction is mediated by protein kinase C (PKC). $^{45}Ca^{2+}$ uptake by rabbit carotid artery was increased by PDBu during depolarization, but not in control. Isoproterenol and sodium nitroprusside (SNP) relaxed phenylephrine-induced contraction. However, SNP but not isoproterenol relaxed the contraction induced by PDBu. Acetylcholine relaxed PDBu-induced contraction in the presence of the endothelium. 8-bromo-cyclic AMP, a permeable analogue of cyclic AMP, suppressed phenylephrine-induced contraction but not PDBu-induced contraction. 8-bromo cyclic GMP relaxed both of them with dose dependency. A large dose of forskolin relaxed PDBu-induced contraction. PDBu increased cyclic AMP without considerable change in the level of cyclic GMP. Based on these findings, PDBu-induced contraction of rabbit carotid artery was relaxed by cyclic GMP more effectively than cyclic AMP, and the action of cyclic AMP could be mediated by cyclic GMP dependent protein kinase. Therefore it is suggested that the antagonistic action between protein kinase C and cyclic GMP-dependent protein kinase plays a major role in the regulation of vascular tone.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.181-190
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• 1994

Endothelium-derived relaxing factor (EDRF) activates guanylate cyclase which mediates the formation of cGMP from GTP in vascular smooth muscle. It is well known that endothelium-dependent relaxation is impaired in spontaneously hypertensive rats (SHR). However, it is still unknown whether the impaired endothelium-dependent relaxation in SHR results from the reduced release of EDRF or from the decrease of vascular response to EDRF. We investigated the effects of cGMP on the contractility and Ca movement in the aorta of SHR and Wistar-Kyoto rats (WKY). The amplitude of the endothelium-dependent relaxation to actylcholine (ACh) was significantly less in SHR than in WKY. L-arginine $(10^{-3}M)$ did not increase endothelium-dependent relaxation in both strains. Sodium nitroprusside (SNP), an activator of guanylate cyclase, relaxed the 40 mM $K^+-induced$ contraction in a dose-dependent manner $(10^{-10}{\sim}10^{-6}\;M)$ in the endothelium-rubbed aortic strips of both strains. However, there was no significant difference in these relaxations between WKY and SHR. 8-bromo-cyclic guanosine monophosphate (8-Br-cGMP), a cell membrane-permeable derivative of cGMP relaxed the 40 mM $K^+-induced$ contraction in a dose-dependent manner $(10^{-6}{\sim}10^{-4}\;M)$ in the endothelium-rubbed aortic strips of both strains. Also norepinephrine $(10^{-6}\;M)-induced$ contractions in normal and Ca-free Tyrode's solution were suppressed by the pretreatment with 8-Br-cGMP $(10^{-4}\;M)$ in either strain. However, the amplitudes of suppression induced by 8-Br-cGMP were greater in SHR than that in WKY. Basal $^{45}Ca$ uptake and 40mM $K^+-stimulated\;^{45}Ca$ uptake were not suppressed by pretreatment with 8-Br-cGMP $(10^{-4}\;M)$ in single aortic smooth muscle cells of both SHR and WKY. From the above results, it is suggested that cGMP decreases Ca sensitivity in vascular smooth muscle cells and that the impaired endothelium-dependent relaxation in the aortic strips of SHR is not the result of a reduced vascular response to EDRF.

• 약학회지
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• 제55권2호
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• pp.138-144
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• 2011

The aim of present study was to investigate the possible influence and related mechanism of resveratrol on U-46619 (high concentration)-induced vasoconstriction. Agonist-induced vascular smooth muscle contractions involve the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in resveratrol-induced relaxation in rat aortae contracted with high U-46619. We hypothesized that MEK or Rho-kinase inhibition plays a role in vascular relaxation evoked by resveratrol in rat aortae. Endothelium-denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Resveratrol fully inhibited U-46619 in low concentration-induced contraction regardless of endothelial function. However, resveratrol partially decreased U-46619 in high concentration-induced contraction regardless of endothelial function. Interestingly, only in U-46619 (high concentration)-induced contraction, no significant decrease was observed in phospho-ERK1/2 levels and slight decrease in phospho-MYPT1 levels suggesting that additional pathways different from them or endothelial nitric oxide synthesis might be involved in the vasorelaxation. In conclusion, in high U-46619-contracted rat aortae, resveratrol showed relaxation response regardless of endothelial function significantly but slightly decreasing MYPT1 phosphorylation rather than ERK1/2 phosphorylation.

• 약학회지
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• 제54권5호
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• pp.392-397
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• 2010

The aim of present study was to investigate the possible influence and related mechanism of additional alcohol on the flavonoid- induced arterial relaxation. Agonist-induced vascular smooth muscle contractions involve the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in quercetin-induced relaxation cotreated with alcohol in rat aortae contracted with phorbol ester, fluoride or thromboxane $A_2$ mimetic U-46619. We hypothesized that cotreated alcohol plays a role in vascular relaxation evoked by quercetin in rat aortae. Endothelium-denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Quercetin inhibited phorbol ester, fluoride or thromboxane $A_2$-induced contraction regardless of endothelial function. However, alcohol didn't decrease any agonist-induced contraction. Interestingly, only in thromboxane $A_2$-induced contraction, synergistic results were observed in aortae denuded and cotreated with quercetin and alcohol suggesting that additional pathways different from antioxidation or endothelial nitric oxide synthesis might be involved in the vasorelaxation. In conclusion, in the agonists-contracted rat aortae, quercetin and alcohol together showed synergistic response regardless of endothelial function in an agonist-dependent manner.

• The Korean Journal of Physiology
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• 제21권2호
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• pp.191-200
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• 1987

The activation mechanism of the sustained contractions induced by norepinephrine and K-depolarization was studied in renal vascular muscle. Helical strips of arterial muscle were prepared from rabbit renal arteries. All experiments were performed in Tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. Renal arterial muscles developed a contracture rapidly when exposed to a 40 mM K-Tyrode solution. In the absence of external $Ca^{2+}$, however, no K-contracture appeared. The contracture induced by K-depolarization was abolished by the treatment with $Ca^{2+}-antagonist\;(verapamil)$ or lanthanum $(La^{3+})$. From these results, it is obvious that K-contracture of renal arterial strip required $Ca^{2+}$ in the medium and this contracture was developed by the increased $Ca^{2+}-influx$ due to K-depolarization. Noradrenaline (5 mg/l) induced also a similar sustained contraction rapidly in all strips. Even on the K-contracture and in $Ca^{2+}-free$ Tyrode solution and also in the Tyrode solution pretreated with verapamil or $La^{3+}$, noradrenaline produced a contraction. However, the contraction in $Ca^{2+}-free$ Tyrode solution was not sustained and decreased gradually. The amplitude of noradrenaline-induced contracture was dependent on external $Ca^{2+}$; The contracture increased dose-dependently, but over 3 mM $Ca^{2+}$, decreased. The results of this experiment suggest that K-contracture was developed by an increased $Ca^{2+}-influx$ due to membrane depolarization, while noradrenaline-induced contracture was developed by both transmembrane $Ca^{2+}-influx$ and the mobilizaiton of cellular $Ca^{2+}$

• Biomolecules & Therapeutics
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• 제26권2호
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• pp.139-145
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• 2018

The present study was undertaken to investigate the influence of hypothermia on endothelium-independent vascular smooth muscle contractility and to determine the mechanism underlying the relaxation. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Hypothermia significantly inhibited fluoride-, thromboxane $A_{2-}$, phenylephrine-, and phorbol ester-induced vascular contractions regardless of endothelial nitric oxide synthesis, suggesting that another pathway had a direct effect on vascular smooth muscle. Hypothermia significantly inhibited the fluoride-induced increase in pMYPT1 level and phorbol ester-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxing effect of moderate hypothermia on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activities.

• Journal of Chest Surgery
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• 제28권8호
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• pp.742-746
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• 1995

The present study was aimed at investigating possible transmitter mechanisms in the endothelial cell layer in regulating the tone of the vascular smooth muscle. The thoracic aorta was isolated from the anesthetized male white rabbits and its helical strips were prepared. Electrical field stimulation was delivered to platinum wire electrodes positioned parallel to the vessel segment preconstricted with phenylephrine [3.5x10-6 mol/L at a distance of 1.5-2.0 mm. The electrical stimulation [70 V, 5 msec, 0.5-200 Hz caused either relaxation only [34% or a biphasic response [prolonged relaxation following a weak and transient contraction, 66% . The relaxation response was frequency- dependent, and at 200 Hz a complete relaxation was noted. Mechanical rubbing of the endothelial layer abolished or greatly attenuated the relaxation. The relaxation was also markedly attenuated in the presence of NG-nitro- L-arginine methyl ester [10-3mol/L or procaine hydrochloride [3.5x10-4mol/L . Tetrodotoxin,guanethidine, atropine or indomethacin failed to block or enhance the relaxation response to electrical field stimulation. It is concluded that the vascular endothelium in the aorta contains diffusible substances that regulates the function of the smooth muscle layer, in which relaxation is more prominent than contraction. Their release by the electrical stimualtion in vitro may not involve classic neuronal transmitter release mechanisms or metabolism of arachidonic acids by cyclooxygenase. The release of the relaxing agents may require an increase in cytosolic calcium level. The chemical nature of the relaxant may be, to a large extent, nitric oxide.