• Title/Summary/Keyword: Smooth muscle contraction

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Inhibition by Higenamine of Lipopolysaccharide-induced iNOS mRNA Expression and NO Production in Rat Aorta (Lipopolysaccharide로 활성화시킨 흰쥐 혈관의 iNOS 발현에 대한 Higenamine의 효과)

  • Kang Young-Jin;Lee Goun-Woo;Ku Eui-Bon;Lee Hoi-Young;Chang Ki-Churl
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.3
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    • pp.297-302
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    • 1997
  • Higenamine was widely used as traditional remedy for the treatment of rhumatoid arthritis. Nitric oxide(NO) may be a critical mediator in this inflammatory disease. Synovial tissue from humans with inflammatory arthritis expresses NOS2(iNOS) mRNA and protein, and generates NO in vitro. We therefore, investigated the effect of higenamine on the induction of nitric oxide synthase(NOS) promoted by lipopolysaccharide(LPS). Prophylactic application of higenamine selectively prevented LPS-primed initiation of L-arginine-induced relaxation and restored rhenylephrine(PE)-induced contraction in rat aorta. LPS-stimulated nitrite production in the incubation medium was reduced by higenamine. Furthermore, RT-PCR and Northern analysis indicated that higenamine reduced iNOS expression primed by LPS in rat aorta. These results suggest that higenamine prevents LPS-promoted induction of NOS in vascular smooth muscle.

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Effects of Lipopolysaccharide-Induced Heme Oxygenase and Carbon Monoxide Production on the Aortic Contractility (Lipopolysaccharide에 의한 Heme Oxygenase Induction과 Carbon Monoxide생성이 혈관수축력에 미치는 영향)

  • 장우성;손의동;이석용
    • YAKHAK HOEJI
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    • v.45 no.1
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    • pp.78-84
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    • 2001
  • Heme oxygenase is a rate-limiting enzyme in heme catabolism that cleaves heme to form biliverdin, iron, and carbon monoxide. Heme oxygenase-1 is expressed in many types of cells and tissues and is highly induced in response to oxidative stress. Carbon monoxide, one of the products of heme oxygenase, can stimulate soluble guanylate cyclase and dilate the vascular smooth muscle. So, the induction of heme oxygenase by lipopolysaccharide (LPS)-induced oxydative stress and the effect of the resultant carbon monoxide on aortic contractility were examined in this study. Zinc protoporphyrine IX (ZnPP), a inhibitor of heme oxygenase, elicited weak contraction of thoracic aortic ring, and this effect was more potent in aorta of LPS-treated rats than control and was blocked by methylene blue. The hyperreactivity to ZnPP in LPS-treated group was blocked by co-treatment with aminoguanidine. In the aortic ring of LPS-treated rats, ZnPP didn't change the vasoreactivity to phenylephrine or acetylcholine. ZnPP elicited hyper-tensive effect in concious rats, and pretreatment with LPS did not affect this effect. Prazosin significantly diminished the hypertensive effect of ZnPP. These results indicate that LPS induced heme oxygenase in aotra, and the resultant carbon monoxide diminished the aortic reactivity to vasoconstrictor.

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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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Pulse Exposure to Ethanol Augments Vascular Contractility Through Stress Response

  • Yang, Eun-Kyoung;Kim, In-Kyeom
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.47-53
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    • 2001
  • Drinking excessive alcohol has been recognized as a risk factor for hypertension. However, the mechanism by which alcohol intake causes hypertension still remains elusive. We tested the hypothesis that ethanol itself acts as a stress factor on vasculature and indirectly modulates vascular contractility. After end of exposure to 1, 2.5 and 5% ethanol for 45 min, rat aortic strips were subjected to contractile responses, immunoblot for Hsp70 and the measurement of levels of myosin light chain phosphorylation. Exposure to 5% ethanol not only augmented contractions to KCl or phenylephrine, but also increased expression of Hsp70 and the levels of myosin light chain phosphorylation. There were no significant differences in contractions produced by $1\;{\mu}mol/L$ phorbol 12,13-dibutyrate, a protein kinase C activator, whether the tissues were exposed to 5% ethanol or not. This is the first report to show that even short exposure to ethanol has a delayed effect to increase vascular smooth muscle contractility through a modulation of thick filament regulation. It may be a mechanism by which ingestion of alcohol induces hypertension.

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Regulatory Effect of Spray-Dried Lactiplantibacillus plantarum K79 on the Activation of Vasodilatory Factors and Inflammatory Responses

  • Ki Hwan Kim;Yongjin Hwang;Seok-Seong Kang
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.216-224
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    • 2024
  • The reduction of nitric oxide (NO) bioavailability in the endothelium induces endothelial dysfunction, contributing to the development of hypertension. Although Lactobacillus consumption decreases blood pressure, intracellular signaling pathways related to hypertension have not been well elucidated. Thus, this study examined the effect of spray-dried Lactiplantibacillus plantarum K79 (LpK79) on NO production, intracellular signaling pathways, and inflammatory responses related to vascular function and hypertension. NO production was assessed in human umbilical vein endothelial cells (HUVECs) treated with LpK79. Endothelial NO synthase (eNOS) and intracellular signaling molecules were determined using Western blot analysis. LpK79 dose-dependently increased NO production and activated eNOS via the phosphoinositide 3-kinase/Akt signaling pathway HUVECs. Moreover, LpK79 mitigated the activation of crucial factors pivotal for vascular contraction in smooth muscle cells, such as phospholipase Cγ, myosin phosphatase target subunit 1, and Rho-associated kinase 2. When HUVECs were treated with LpL79 in the presence of Escherichia coli lipopolysaccharide (LPS), LpK79 effectively suppressed mRNA and protein expression of pro-inflammatory mediators induced by E. coli LPS. These results suggest that LpK79 provided a beneficial effect on the regulation of vascular endothelial function.

Relaxing Effects of Acanthopanacis Cortex through NO Production and PDE-5 Inhibition in Corpus Cavernosum (오가피의 NO 생성과 PDE-5 억제를 통한 음경해면체 이완효과)

  • Kim, Ho Hyun;Park, Sun Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.1
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    • pp.52-58
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    • 2017
  • This study was aimed to examine relaxing effects of Acanthopanacis cortex(AC) through nitric oxide(NO) production and phosphodiesterase type 5(PDE-5) inhibition in corpus cavernosum. In order to define the relaxation effects of AC extract, rabbit corpus cavernous tissues were prepared in $2{\times}2{\times}8mm$ sized strip. AC extract ($0.01-3.0mg/m{\ell}$) were treated in contracted strips induced by phenylephrine(PE) and $N{\omega}$-nitro-L-arginine (L-NNA) was treated before AC extract-treated. And calcium chloride($Ca^{2+}$) 1 mM was infused into precontracted strips after pretreatment of AC extract in $Ca^{2+}-free$ krebs-ringer solution. When AC extract was applied to human umbilical vein endothelial cell(HUVEC), cell viability was measured by MTT assay, and NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS, PDE-5 positive reaction were measured by histochemical and immunohistochemical process on mice corpus cavernosum. AC extract significantly affected relaxion of the cavernous strips, and the pretreatment of L-NNA inhibited AC extract-induced relaxation. Contraction induced by the addition of $Ca^{2+}$ was inhibited by treatment with the AC extract in $Ca^{2+}-free$ solution. In AC group, NO concentration, ratio of smooth muscle to collagen fibers, and eNOS positive reaction were increased, PDE-5 positive reaction was decreased compared to PE group. As a result of the above experiment, it was thought that AC extract inhibits the inflow of extracellular $Ca^{2+}$ by activating cGMP through the increase of eNOS / NO and the decrease of PDE-5 which inhibits cGMP activity, in the corpus cavernosum.

Variations of Adrenergic Receptors of Oviduct Porprius in Relation ot Egg Production in Leghorn (레그호온의 산란유무(産卵有無)에 따른 Adrenergic Receptor의 변동(變動))

  • Hong, Ki Whan
    • The Korean Journal of Pharmacology
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    • v.13 no.1 s.21
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    • pp.13-21
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    • 1977
  • The author confirmed the development of the smooth muscle in the oviduct proprius and anterior mesosalpinx in the leghorn, and observed that there was a variation between the action of norepinephrine on albumin-secreting portion of productive oviduct and that of non-productive one, and that $PGE_1$ might play a significant role on the activation of adrenergic ${\alpha}$-receptor in the non-productive oviduct. 1. There were many bundles of smooth muscles with irregular directions, which were identified in the both oviduct proprius and anterior mesosalpinx by Mallory aniline-blue orange G stain. 2. In vitro experiments, the anterior mesosalpinx was always relaxed by norepinephrine. While the albumin-secreting portion of non-productive period of oviduct was relaxed, but that of the productive one contracted by norepinephrine. Both the anterior mesosalpinx and oviduct proprius of chick responsed with relaxation to norepinephrine as shown in the non-productive hen. In vivo experiments, norepinephrine injected through the jugular vein increased the intraoviductal pressure in the productive oviduct, but decreased that in the non-productive one. 3. By treatment with $PGE_1$, in vitro, the relaxation induced not only by norepinephrine, but by periarterial electrical stimulation was converted into contraction, and in the presence of phentolamine, this conversion by $PGE_1$ was not shown. 4. The intra-oviductal pressure of the productive hen treated with indomethacin for 4 days was decreased by norepinephrine, but the increase in pressure by $PGE_1$ or $PGE_{2{\alpha}}$ was supersensitized when these drugs were administered through jugular vein. However, in vivo, the relaxation by norepinephrine was not converted into the stimulation after $PGE_1$ treatment. It might be summarized that the regulation of intra-oviductal pressure was dependent on the summation of the movement of both oviduct and mesosalpinx and intramurally produced prostaglandins contributes to the inherent tone of the prcductive oviduct by activating adrenergic ${\alpha}$-receptor.

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Biphasic Mechanical Responses of Rat Thoracic Aorta to Irradiation with $250{\sim}500\;nm$ Light (돼지 관상동맥 및 흰쥐 흉부대동맥에서 자외선 및 가시광선 조사시 파장에 따른 기계적 반응과 Cyclic GMP의 농도변화)

  • Kook, Hyun
    • The Korean Journal of Pharmacology
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    • v.31 no.3
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    • pp.285-290
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    • 1995
  • This study was undertaken to define the varying responses of vascular smooth muscle to different wavelengths of ultraviolet radiation and to relate them to the changes in cyclic GMP contents. The ring preparations of rat thoracic aorta with intact or removed endothelium were irradiated with the ultraviolet or visible light (UVR) of wavelengths in step of 10 nm between 250 and 500 nm from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorded. For cyclic GMP assay, the preparations, pretreated with phenylephrine as in the tension experinents, were frozen after irradiation and homogenated in trichloroacetic acid. The supernatant was extracted with ether and the cyclic GMP contents were measured with radioimmunoassay. In the endothelium-intact preparations, biphasic responses, vasoconstriction (UVR-contraction) followed by vasodilatation (UVR-dilatation), were observed. The maximal UVR-contraction was observed at 320 nm, while the maximal vasodilatation was elicited at 420 nm. In the endothelium-removed rings, however, only vasodilatation was observed, with the maximal vasodilatation taking place at 370 nm. The cyclic GMP contents were not affected by the Irradiation with 320 nm for 30 sec or 1 min in the endothelium-intact preparations, while it was significantly increased by 380 and 420 nm. In the endothelium-removed preparations, UVR of 370 nm markedly increased the cyclic GMP contents. The present study indicates that the increase in cyclic GMP is closely related to vasodilatation induced by UVR of 420 nm in the endothelium-intact or 370 nm in the denuded preparations, whereas it is not involved in the vasoconstriction induced by UVR of 320 nm in the intact rings, and the mechanism leading to UVR-contraction remains to be clarified. These observations suggest that nitric oxide-cyclic GMP system is closely related to the UVR-dilatation in rat aortic preparation, while it is not involved in the UVR contraction.

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Antispasmodic Effects of Junsibaekchul-San In Vivo and In vitro

  • Hur, Jin-Il;Byun, Joon-Seok;Kim, Dae-Jun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.1
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    • pp.143-151
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    • 2010
  • In Vivo and In vitro antispasmodic effects of Jun-Si-Baek-Chul-San, a Traditional Korean Polyherbal Medicineconsisted of 7 types of herbs were observed in the present study. To clarify the effects of Jun-Si-Baek-Chul-San, on accelerating small intestinal movement induced by the stimulation of cholinergic neurotransmission, we evaluated the effects of Jun-Si-Baek-Chul-San on In vivo carbachol (an acetylcholinergic agent)-accelerated mice small intestinal transit and on In vitro contractions induced by low-frequency electrostimulation, KCl, histamine or acetylcholine using isolated guinea pig ileum. To induce the acceleration of mice small intestinal transit, Carbachol 1 mg/kg was once subcutaneously dosed 15min before last administration of the test drugs. In the present study, Jun-Si-Baek-Chul-San 500, 250 and 125 mg/kg or domperidone 20 mg/kg were orally pretreated on the carbachol-accelerated mice small intestinal transit once a day for 7 days and the small intestinal transit rateof activated charcoal powder were monitored. In vitro assays, Jun-Si-Baek-Chul-San1, 0.1, 0.01 and 0.001 mg/ml or domperidone $2{\times}10^{-5}M$ were treated 10min before ileal contraction was induced by filed stimulation, acetylcholine, KCl and histamine, and the % changes of contractions were observed compared to the treatment of inducer alone. In spontaneous contraction, the % changes of contractions were observed compared to treatment of vehicle alone at 10min after Jun-Si-Baek-Chul-San or domperidone treatment. The efficacy of Jun-Si-Baek-Chul-San was compared to those of domperidone. High concentration, 1 mg/ml of Jun-Si-Baek-Chul-San was found to decrease the spontaneous contraction of the isolated guinea-pig ileum. In addition, Jun-Si-Baek-Chul-San decrease contractions induced by electrostimulation, acetylcholine, histamine and KCl in the isolated guinea-pig ileum. In addition, Jun-Si-Baek-Chul-San effectively inhibited the accelerated small intestinal movement induced by carbachol stimulation of cholinergic neurotransmission in In vivo. Based on the results, although the exact molecular or action mechanism and which herbs or compound in Jun-Si-Baek-Chul-San are responsible for actions, it was concluded that Jun-Si-Baek-Chul-San normalization in the accelerated intestinal motility might be interfere with a variety of muscarinic, adrenergic and histaminic receptor activities or with the mobilization of calcium ions required for smooth muscle contraction non-specificly. Therefore, it is expected that Jun-Si-Baek-Chul-San will be promising as a prescription of clinical treatment of digestive tract disorders such as accelerated the motility of intestine, diarrhea or intestinal painful contractions.

Role of T-type $Ca^{2+}$ Channels in the Spontaneous Phasic Contraction of Pregnant Rat Uterine Smooth Muscle

  • Lee, Si-Eun;Ahn, Duck-Sun;Lee, Young-Ho
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.3
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    • pp.241-249
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    • 2009
  • Although extracellular $Ca^{2+}$ entry through the voltage-dependent $Ca^{2+}$ channels plays an important role in the spontaneous phasic contractions of the pregnant rat myometrium, the role of the T-type $Ca^{2+}$ channels has yet to be fully identified. The aim of this study was to investigate the role of the T-type $Ca^{2+}$ channel in the spontaneous phasic contractions of the rat myometrium. Spontaneous phasic contractions and $[Ca^{2+}]_i$ were measured simultaneously in the longitudinal strips of female Sprague-Dawley rats late in their pregnancy (on day 18 ${\sim}$ 20 of gestation: term=22 days). The expression of T-type $Ca^{2+}$ channel mRNAs or protein levels was measured. Cumulative addition of low concentrations (< 1 ${\mu}M$) of nifedipine, a L-type $Ca^{2+}$ channel blocker, produced a decrease in the amplitude of the spontaneous $Ca^{2+}$ transients and contractions with no significant change in frequency. The mRNAs and proteins encoding two subunits (${\alpha}$ 1G, ${\alpha}$ 1H) of the T-type $Ca^{2+}$ channels were expressed in longitudinal muscle layer of rat myometrium. Cumulative addition of mibefradil, NNC 55-0396 or nickel induced a concentration-dependent inhibition of the amplitude and frequency of the spontaneous $Ca^{2+}$ transients and contractions. Mibefradil, NNC 55-0396 or nickel also attenuated the slope of rising phase of spontaneous $Ca^{2+}$ transients consistent with the reduction of the frequency. It is concluded that T-type $Ca^{2+}$ channels are expressed in the pregnant rat myometrium and may play a key role for the regulation of the frequency of spontaneous phasic contractions.