• Biomolecules & Therapeutics
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• 제10권4호
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• pp.258-267
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• 2002

In this study the general pharmacological profiles of AS6 on the central nervous system, cardiovascular and the other organs were investigated. The dosages given were 0, 250, 500 and 1000 mg/kg and drugs were orally administered. The animals used for this study were mice, rats and guinea pigs. Significant increases (p<0.01) in the charcoal transport capacity were observed at the high dose of 1000 mg/kg and significant increases in retardation of pain threshold were observed in the test using acetic acid in all dosed animals. However, AS6 showed no noticeable effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital-induced sleep time, body temperature, analgesic activity in the test using hot plate method and anticonvulsant activity. Furthermore no noticeable effects were observed in cardiovascular functions in the isolated rat heart, contraction and relaxation of the smooth muscle in the isolated guinea ileum, gastric secretion and renal function.

• The Korean Journal of Physiology and Pharmacology
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• 제22권4호
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• pp.437-445
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• 2018

${\alpha}$-Iso-cubebene (ICB) is a dibenzocyclooctadiene lignin contained in Schisandra chinensis (SC), a well-known medicinal herb that ameliorates cardiovascular symptoms, but the mechanism responsible for this activity has not been determined. To determine the role played by ICB on the regulation of vascular tone, we investigated the inhibitory effects of ICB on vascular contractile responses by adrenergic ${\alpha}$-receptor agonists. In addition, we investigated the role on myosin light chain (MLC) phosphorylation and cytosolic calcium concentration in vascular smooth muscle cells (VSMC). In aortic rings isolated from C57BL/6J mice, ICB significantly attenuated the contraction induced by phenylephrine (PE) and norepinephrine (NE), whereas ICB had no effects on KCl (60 mM)-induced contraction. In vasculatures precontracted with PE, ICB caused marked relaxation of aortic rings with or without endothelium, suggesting a direct effect on VSMC. In cultured rat VSMC, PE or NE increased MLC phosphorylation and increased cytosolic calcium levels. Both of these effects were significantly suppressed by ICB. In conclusion, our results showed that ICB regulated vascular tone by inhibiting MLC phosphorylation and calcium flux into VSMC, and suggest that ICB has anti-hypertensive properties and therapeutic potential for cardiovascular disorders related to vascular hypertension.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• 제21권6호
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• pp.687-694
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• 2017

Plumbagin, a hydroxy 1,4-naphthoquinone compound from plant metabolites, exhibits anticancer, antibacterial, and antifungal activities via modulating various signaling molecules. However, its effects on vascular functions are rarely studied except in pulmonary and coronary arteries where NADPH oxidase (NOX) inhibition was suggested as a mechanism. Here we investigate the effects of plumbagin on the contractility of skeletal artery (deep femoral artery, DFA), mesenteric artery (MA) and renal artery (RA) in rats. Although plumbagin alone had no effect on the isometric tone of DFA, $1{\mu}M$ phenylephrine (PhE)-induced partial contraction was largely augmented by plumbagin (${\Delta}T_{Plum}$, 125% of 80 mM KCl-induced contraction at $1{\mu}M$). With relatively higher concentrations (>$5{\mu}M$), plumbagin induced a transient contraction followed by tonic relaxation of DFA. Similar biphasic augmentation of the PhE-induced contraction was observed in MA and RA. VAS2870 and GKT137831, specific NOX4 inhibitors, neither mimicked nor inhibited ${\Delta}T_{Plum}$ in DFA. Also, pretreatment with tiron or catalase did not affect ${\Delta}T_{Plum}$ of DFA. Under the inhibition of PhE-contraction with L-type $Ca^{2+}$ channel blocker (nifedipine, $1{\mu}M$), plumbagin still induced tonic contraction, suggesting $Ca^{2+}$-sensitization mechanism of smooth muscle. Although ${\Delta}T_{Plum}$ was consistently observed under pretreatment with Rho A-kinase inhibitor (Y27632, $1{\mu}M$), a PKC inhibitor (GF 109203X, $10{\mu}M$) largely suppressed ${\Delta}T_{Plum}$. Taken together, it is suggested that plumbagin facilitates the PKC activation in the presence of vasoactive agonists in skeletal arteries. The biphasic contractile effects on the systemic arteries should be considered in the pharmacological studies of plumbagin and 1,4-naphthoquinones.

• 대한한의학방제학회지
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• 제17권2호
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• pp.175-186
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• 2009

The vasorelaxant effect of an extract of Lophatherum gracile Brongn (ELB) and its possible action mechanism were ascertained in aortic tissues isolated from rats. ELB relaxed endothelium-intact thoracic aorta in a dose-dependent manner. However, the induced vascular relaxation was abolished by removal in endothelium of the thoracic aorta. Pretreatment of endothelium-intact vascular tissues with $N^G$-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-$\alpha$]-quinoxalin-1-one (ODQ) significantly inhibited vascular relaxation induced by ELB. Moreover, ELB significantly increased cGMP production in aortic tissues, which was blocked by pretreatment with L-NAME or ODQ. The vasorelaxant effect of ELB was attenuated by tetraethylammonium (TEA), and glibenclamide. ELB-induced vasorelaxation was not blocked by atropine, propranolol, indomethacin, verapamil, and diltiazem. Taken together, the present study demonstrates that ELB dilates vascular smooth muscle via an endothelium-dependent NO-cGMP signaling pathway, which may be at least in part related with the function of $K^+$ channels.

• Journal of Yeungnam Medical Science
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• 제23권1호
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• pp.52-61
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• 2006

이상의 결과를 종합하면, 인삼 총사포닌은 본 실험의 조건에서 배뇨개선 효과가 있으며 이에 관여하는 총사포닌의 주 효능은 근위부요도를 이완시킴으로써 이루어지는 것으로 생각된다. 그리고 인삼 총사포닌은 혈류역동학적으로 안전하게 음경해면체 평활근을 이완시켜 음경발기를 유발시키는 것으로 생각된다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.873-878
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• 2002

OA-8159, a new Phosphodiesterase (PDE) 5 inhibitor, has exhibited potent erectogenic potential in a penile erection test in rats and anesthetized dogs. In this study, we investigated the mechanism of its erectogenic activity by measuring the activity of OA-8159 against a various PDE isozymes and assessing cGMP and cAMP formation in a rabbit corpus cavernosum in vitro. DA-8159 inhibited the PDE 5 activity in rabbit and human platelets, which the $IC_{50}$ was 5.84$\pm$1.70 nM and 8.25$\pm$2.90 nM, respectively. The $IC_{50}$ of DA-8159 on PDE 1, PDE2, PDE 3 and PDE 6 were 870$\pm$57.4 nM, $101\pm$5 $\mu$M, 52.0$\pm$3.53 $\mu$M and 53.3$\pm$2.47 nM, respectively. This suggests that DA-8159 is a potent, highly selective, competitive inhibitor of PDE 5-catalyzed cGMP hydrolysis. The rates of cGMP hydrolysis catalyzed by human platelets-derived PDE 5 as a function of the cGMP concentration (5~100 nM) and two-fixed DA-8159 concentration (11.3 and 18.8 nM) were investigated in order to characterize the mode of PDE 5 inhibition by DA-8159. DA-8159 increased the apparent 4K_{m}$ value for cGMP hydrolysis but had no effect on the apparent $V_{max}$, indicating a competitive mode of inhibition. DA-8159 increased the cGMP concentrations in the rabbit corpus cavernosum dose dependently. In the presence of sodium nitroprusside (SNP), DA-8159 significantly sti\mulated the accu\mulation of cGMP when compared to the control level. This indicated that the enhancement of a penile erection by DA-8159 involved the relaxation of the cavernosal smooth \muscle by NO-sti\mulated cGMP accu\mulation. In conclusion, DA-8159 is a selective inhibitor of PDE 5-catalyzed cGMP hydrolysis and the enhancement of a penile erection by DA-8159 is mediated by the relaxation of the cavernosal smooth \muscle by the NO-sti\mulated cGMP accu\mulation.

• Journal of Yeungnam Medical Science
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• 제8권2호
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• pp.95-105
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• 1991

흰쥐 적출소장의 수축성에 미치는 GABA의 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. GABA는 소장을 이완시켰으며 그 이완 작용은 십이지장, 공장 그리고 회장의 순이었다. GABA A수용체 효현제인 muscimol 역시 소장을 이완시켰으며, 그 효능의 강도는 십이지장, 공장 그리고 회장의 순이었다. 그러나 GABA B수용체 효현제인 baclofen은 소장의 운동성에 유의한 영향을 미치지 못하였다. 2. 상경적 GABA A수용체 길항제인 bicuculline과 비 상경적 GABA A수용체 길항제인 picrotoxin은 십이지장에 대한 GABA와 muscimol의 이완 작용을 현저히 억제시켰다. 그리고 bicuculline의 억제 작용이 picrotoxin 보다 강하였다. 3. Sodium channel blocker인 tetrodotoxin은 GABA의 이완 작용을 봉쇄하였다. 4. 신경절 봉쇄적인 hexamethonium은 십이지장에 대한 GABA의 이완작용을 길항하지 못하였다. 이상의 실험 결과로 볼 때 흰쥐 소장의 자발 수축운동에 대한 GABA의 이완작용은 소장이 부위에 따라 다르게 나타나며, 그 작용은 postganglionic presynaptic neuron에 존재하는 GABA A 수용체에 작용함으로써 나타나는 것으로 사료된다.

• 동의생리병리학회지
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• 제27권5호
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• pp.602-610
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• 2013

This study was aimed to evaluate the cavernosal relaxation effect of Crataegii fructus(CF) in the contracted rabbit penile corpus cavernosum by agonists.In order to study the effect of CF on the vasoconstriction of rabbit penile corpus cavernosum, isolated rabbit penile corpus cavernosum tissues were used for the experiment using organ baths containing Krebs solution.To investigate the cavernosal relaxation of CF, CF extract at $0.01{\sim}3.0mg/m{\ell}$ was added after penile corpus cavernosum were contracted by norepinephrine(NE) $1{\mu}M$. To analyze the mechanism of CF's vasorelaxation, CF extract infused into contracted penile tissues by NE after each treatment of indomethacin(IM), $N{\omega}$-nitro-L-arginine(L-NNA), methylene blue(MB), tetraethylammonium chloride(TEA).To study the effect of CF on influx of extracellular calcium chloride($Ca^{2+}$) in penile tissues, in $Ca^{2+}$-free krebs solution, $Ca^{2+}$ 1 mM infused into contracted penile tissues by NE after pretreatment of CF. Cytotoxic activity of CF on human umbilical vein endothelial cell(HUVEC) was measured by MTT assay, and nitric oxide(NO) prodution was measured by Griess reagent. CF relaxed cavernosal strip with endothelium contracted by NE, but in the strips without endothelium, CF-induced relaxation was significantly inhibited. The pretreatment of L-NNA, MB, TEA decreased significantly on the cavernosal relaxation than not-treatment of them. But the pretreatment of IM had no significant effect on the cavernosal relaxation. In $Ca^{2+}$-free krebs solution, when $Ca^{2+}$ infused into contracted penile tissues by NE, pretreatment of CF inhibit contraction induced by adding $Ca^{2+}$.NO production wasn't increased by treatment of CF on HUVEC. This findings showed that CF is effective for the relaxation of rabbit penile corpus cavernosum, and we suggest that CF relax rabbit corpus cavernosal smooth muscle through multiple action mechanisms that include increasing the release of nitric oxide from corporal sinusoidal endothelium, inhibition of $Ca^{2+}$ mobilization into cytosol from the extracellular fluid, and maybe a hyperpolarizing action.

• Journal of Chest Surgery
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• 제32권4호
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• pp.333-340
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• 1999

배경: PAI-1은 t-PA의 억제인자로서 섬유소융해계에 작용을 하여 혈전형성을 유발한다. PAI-1은 동맥경화된 혈관벽에서 분비가 된다. PAI-1의 증가는 동맥경화증의 위험인자가 되는 당뇨병과 고혈압이 동반된 환자에서 보이며 혈전증유발에 위험인자가 될 수 있다. 본 연구는 고혈당과 인슐린 및 angiotensin II가 PAI-1의 생성 및 평활근세포의 증식에 미치는 영향을 규명하고자 하였다. 대상 및 방법:흰쥐 대동맥평활근세포를 5.5 mM과 22 mM의 포도당 배양액을 사용하여 배양하였다. 배양액에 angiotensin II 및 인슐린을 농도 및 배양시간에 따라 첨가하여 Northern blotting방법으로 PAI-1 유전자발현을 나타내었다. 또한 세포 증식에 대한 포도당, 인슐린 및 angiotensin II의 영향을 규명하기 위하여 MTT assay를 사용하였다. 결과: 5.5 mM과 22 mM의 포도당 배양액에서 angiotensin II(100 nM)를 첨가하여 배양한 결과, 22 mM 포도당 배양액에서 PAI-1 mRNA 발현이 증가되었으며 angiotensin II 투여 4시간에 최고치에 도달하였고 6시간까지 지속되었다. 5.5 mM, 22 mM의 포도당 배양액에 angiotensin II의 농도를 0, 10, 100, 200 nM 투여하여 배양한 결과, PAI-1 mRNA의 발현은 angiotensin II 농도에 따른 증가를 보였으며 22 mM 포도당 배양액시 더욱 뚜렷하게 증가되었다. 배양액에 angiotensin II(100 nM)과 인슐린(100 nM)을 투여하여 배양한 결과, PAI-1 mRNA의 발현은 angiotensin II 단독으로 투여시 증가하였으나 인슐린을 첨가하였을 때는 감소하였다. 5.5 mM과 22 mM의 포도당 배양액에 1, 10, 100 nM의 인슐린과 1, 10, 100 nM의 angiotensin II를 첨가한 후 대동맥평활근세포의 성장속도를 비교한 결과, 5.5 mM보다 22 mM의 포도당이 든 배양액에서 대동맥평활근세포의 성장이 촉진되었으며, 인슐린 및 angiotensin II를 첨가한 경우도 대동맥평활근세포의 성장이 증가되었다. 결론:흰쥐 대동맥평활근세포에서 PAI-1 mRNA의 발현은 포도당 농도가 높을수록 증가되며 angiotensin II의 농도 및 배양시간에 따라 증가되고 인슐린 투여로 감소하였다. 또한 angiotensin II의 투여는 22 mM의 고농도 포도당 투여 후 증가된 PAI-1 mRNA 발현 증가를 더욱 증가시켜 PAI-1 mRNA 발현 증가에 상승작용이 있음을 알 수 있다. 그리고 22 mM의 고농도 포도당, 인슐린 및 angiotensin II는 흰쥐의 대동맥평활근세포의 성장을 촉진시켰다.