• Title/Summary/Keyword: vasoconstriction

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Epidermal Growth Factor Induces Vasoconstriction Through the Phosphatidylinositol 3-Kinase-Mediated Mitogen-Activated Protein Kinase Pathway in Hypertensive Rats

  • Kim, Jung-Hwan;Lee, Chang-Kwon;Park, Hyo-Jun;Kim, Hyo-Jin;So, Hyun-Ha;Lee, Keun-Sang;Lee, Hwan-Myung;Roh, Hui-Yul;Choi, Wahn-Soo;Park, Tae-Kyu;Kim, Bo-Kyung
    • Journal of Korean Physical Therapy Science
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    • v.13 no.2
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    • pp.137-145
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    • 2006
  • We investigated whether increased contractile responsiveness to epidermal growth factor (EGF) is associated with altered activation of mitogen-activated protein kinase (MAPK) in the aortic smooth muscle of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. EGF induced contraction and MAPK activity in aortic smooth muscle strips, which were significantly increased in tissues from the DOCA-salt hypertensive rats compared with those from sham-operated rats. AG1478, PD98059, and LY294002, inhibitors of EGF receptor (EGFR) tyrosine kinase, MAPK/extracellular signal-regulated kinase (ERK) kinase, and phosphatidylinositol 3-kinase (PI3K), respectively, inhibited the contraction and the activity of ERK1/2 that were elevated by EGF. Y27632 and GF109203X, inhibitors of Rho kinase and protein kinase C, respectively, attenuated EGF-induced contraction, with no diminution of ERK1/2 activity. Although EGF also elevated the activity of EGFR tyrosine kinase in both sham-operated and DOCA-salt hypertensive rats, the expression and the magnitude of activation did not differ between strips. These results strongly suggest that EGF induces contraction by the activation of ERK1/2, which is regulated by the PI3K pathway in the aortic smooth muscle of DOCA-salt hypertensive rats.

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Biological Effects of Static Magnetic Fields and ELF-Electromagnetic Field on Microcirculation in Animals

  • Ohkubo, Chiyoji;Okano, Hidyuki;Xu, Shenzhi;Gmitrov, Jraj
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 1999.07a
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    • pp.117-129
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    • 1999
  • Acute effects of locally applied of static magnetic field (SMF) and extremely low frequency electromagnetic field(ELF-EMF) to the cutaneous tissue within a rabbit ear chamber (REC)were evaluated under conscious conditions. Rabbits with the REC were subjected to intravital microscopical investigation by use of microphotoelectric plethysmography(MPPG). There was no dose-response relationship between the extent of vasomotion changes and frequencies(0,20,50, 100Hz)or power levels (1, 5, 10, 25, 50, 100, 200 mT). Under low vascular tone the both fields induce vasodilatation. The effects of SMF (1 mT) on the cutaneous microcirculatory system induced the vasodilatation with enhanced vasomotion under nor-adrenaline-induced high vascular tone as well as the vasoconstriction with reduced vasomotion under acetylcholine-induced low vascular tone. This suggests that the SMF can modulate vascular tone due to the modification of vasomotion biphasically in the cutaneous tissue.

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Vasorelaxing Effect of Hypoxia via Rho-kinase Inhibition on the Agonist-specific Vasoconstriction

  • Je, Hyun-Dong;Shin, Chang-Yell
    • Biomolecules & Therapeutics
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    • v.16 no.3
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    • pp.249-254
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    • 2008
  • The present study was undertaken to determine whether hypoxia influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Hypoxia significantly inhibited fluoride-induced contraction regardless of endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction suggesting that other pathway such as $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, hypoxia significantly decreased fluoride-induced increase of phospho-myosin-targeting subunit of myosin light chain phosphatase (pMYPT1). Interestingly, hypoxia didn't inhibit significantly phenylephrine-induced contraction suggesting that myosin light chain kinase (MLCK) activity or thin filament regulation is less important on the hypoxia-induced vasorelaxation in the denuded muscle than Rho-kinase activity. In conclusion, this study provides the evidence and possible related mechanism concerning the vasodilation effect of hypoxia on the agonist-specific contraction in rat aortic rings regardless of endothelial function.

Ergotamine-induced Vasospasm (에르고타민으로 인한 혈관경축)

  • Lim Chang Young;Lee Hyeon Jae;Lee Gun
    • Journal of Chest Surgery
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    • v.38 no.3 s.248
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    • pp.245-248
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    • 2005
  • Drugs containing ergotamine are widely used in the treatment of migraine. Spastic vasoconstriction is one of the most serious side effects even with recommended dosage. We report a case of 63-year-old male with severe arterial occlusion of the upper limbs which might be related with vasospasm caused by ergotamine-containing medication because of migraine for f5 years. He was treated with bypass graft, sympathicotomy and heparin and prostaglandin E1 infusion. But dramatic clinical reversal of the vasospasm was obtained after withdrawal of ergotamine.

Effect of Bosentan, $ET_{A+B}$ antagonist, on EAE-induced lewis rat.

  • Park, Young shim;Bong su Kang;In hoi Huh
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.192-192
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    • 1996
  • Endothelin has $ET_{A}$ type and $ET_{B}$ type receptors, and it has been thought that ET-1 proves vasoconstriction effect via $ET_{A}$ receptor and vasodilation via $ET_{B}$ receptor. Recently, it has been reported that $ET_{B}$ receptor is also related to the vaso-constriction. Bosentan is a $ET_{A+B}$ receptor antagonist, and proves it's effect on trauma and ischemia. We already announced that the level of Endothelin-1 increase in the brain and spinal cord of EAE-induced lewis rat and showed the origin of ET-1 is activated macrophages. Intracisternal injection of Bosentan, $ET_{A+B}$ receptor antagonist, (300nmol/body) was done for observing the role of endothelin-1 on the pathogenesis of EAE. Bosentan ameliorated the severity of clinical score of EAE and decreased the histologically observed inflammatory region. The blocking effect on the progression of EAE model suggests that Bosentan is a physiological antagonist in terms of development of the sign of multiple sclerosis.

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Mechanisms of Russell's Viper Venom Toxicity on Renal Function; Reversal by Antivenom

  • Chaiyabutr, Narongsak;Napathorn, Sophon;Sitprija, Visith
    • Toxicological Research
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    • v.17
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    • pp.117-125
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    • 2001
  • Envenoming by Russells viper causes a broad spectrum of renal impairment. Renal failure is an important complication in patients bitten by Russells viper. Experimental work in animals and in vitro has elucidated pathophysiological mechanisms that contribute to life threatening complications and have suggested possibilities for therapeutic intervention. The evidence in experimental animals regarding mechanisms of venom action in relation to changes in either extrarenal or intrarenal factors is presented. The cardiovascular system and renal hemodynamics are affected by venom. Reductions of renal function including renal hemodynamics are associated directly with changes in general circulation during envenomation. Possible endogenous mechanisms for releasing the hormone inducing renal vasoconstriction after envenomation are evident. Hormonal factor such as the catecholamine, prostaglandin and renin angiotensin systems induce these changes. Direct nephrotoxicity of venom action is studied in the isolated per-fused kidney. Characteristic polarization of the cell membrane, changes of mitochondrial activity and Na-K ATPase in renal tubular cells are observed. Changes in renal function and the cardiovascular system are observed of ter envenomation and are reversed by the administration of Russells viper antivenom (purified equine immunoglobulin, $Fab_2$ fragment). The neutralizing effects are more efficient when the intravenous injection of antivenom is given within 30 min after the envenomation.

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Thermoregulatory Characteristics of Feet and Legs in aspects of Covering Effect (피복효과면에서 본 발과 다리의 체온조절적 특성)

  • 이종민
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.7
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    • pp.965-970
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    • 1999
  • This study was conducted to investigate the thermoregulatory characteristics of feet and legs by comparing with the physiological responses according to the covering parts of lower limbs. Five healthy female subjects wore three types of clothing-covered legs and feet(LF-C) with long trousers and socks exposed the legs(L-E) with half trousers and socks and exposed the legs and feet(LF-E) with only half trousers-when the subjects rested at $25^{\circ}C$ and were exposed to 18$^{\circ}C$ for 90 min. Rectal temperatures (Tre) were maintained higher in LF-E than L-E and LF-C at both environments. Decreases of The after exposure to 18$^{\circ}C$ were significantly smaller in LF-E than L-E and LF-C and almost same in L-E and LF-C Heat production in both environments increases of heat production and weight loss after exposure to 18$^{\circ}C$ were not significant among three types of clothing. From these findings it would be suggested that the legs would play the little role of voluntary thermoregulation as vasoconstriction and the role of the legs depend on thermal conditions of feet while the feet play the positive role of voluntary thermoregulation in terms of heat conservation in cool environment.

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Study on the Anti-hypertension mechanism of Prunella Vulgaris based on entity grammar systems

  • Du, Li;Li, Man-man;Zhang, Bai-Xia;He, Shuai-Bing;Hu, Ya-Nan;Wang, Yun
    • CELLMED
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    • v.5 no.4
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    • pp.27.1-27.6
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    • 2015
  • Literatures and experimental studies have shown that Prunella has an effect on anti-hypertension, however, its components are complicated, so that it is still difficult to clear the specific roles of its various components in blood pressure regulation in. So we decide to systematically study the anti-hypertension mechanism of Prunella. We integrated multiple databases and constructed molecular interaction network between the chemical constituents of Prunella Vulgaris and hypertension based on entity grammar systems model. The network has 262 nodes and 802 edges. Then we infer the interactions between chemical compositions and disease targets to clarify the anti-hypertension mechanism. Finally, we found Prunella could influence hypertension by regulating apoptosis, cell proliferation, blood vessel development and vasoconstriction, etc. Thus this study provides reference for drug development and compatibility, and also gives guidance for health care at a certain extent.

Effects of Prostaglandin $F_{2{\alpha}}$ on Membrane Potentials and $K^+$ Currents in Rabbit Middle Cerebral Arterial Cells

  • Kim, Na-Ri;Han, Jin;Kim, Won-Gue;Kim, Eui-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.4
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    • pp.301-309
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    • 2000
  • The purpose of our investigation was to examine the effects of prostaglandin $F_{2{\alpha}}\;(PGF_{2{\alpha}})$ on membrane potentials, $Ca^{2+}-activated\;K^+\;(K_{Ca})$ channels, and delayed rectifier $K^+(K_V)$ channels using the patch-clamp technique in single rabbit middle cerebral arterial smooth muscle cells. $PGF_{2{\alpha}}$ significantly hyperpolarized membrane potentials and increased outward whole-cell K currents. $PGF_{2{\alpha}}$ increased open-state probability of $K_{Ca}$ channels without the change of the open and closed kinetics. $PGF_{2{\alpha}}$ increased the amplitudes of $K_V$ currents with a leftward shift of activation and inactivation curves and a decrease of activation time constant. Our results suggest that the activation of $K_{Ca}$ and $K_V$ channels, at least in part, may lead to attenuate or counteract vasoconstriction by $PGF_{2{\alpha}}$ in middle cerebral artery.

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A Clinic Study of the Treatment for Asthma in Taeumin with RBBB(Right Bundle Branch Block) (태음인(太陰人)의 천식(喘息)을 마황정천탕(麻黃定喘湯)을 사용하여 치료한 치험 1례)

  • Kim, Dal-Rea;Se, Young-Goang;Kim, Sun-Hyung
    • Journal of Sasang Constitutional Medicine
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    • v.19 no.3
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    • pp.293-299
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    • 2007
  • 1. Objectives The main ingredient of ephedra is ephedrine which affects on autonomic nervous system induce some adverse effects just like vasoconstriction, hypertension, tachycardia, miosis, insomnia, dizziness, headache, and etc. and heart disease. If we use Mahuang according to the Sasang constitution classification in clinic, we could not only may minimize the anxiety but maximize the potential curative value in Asthma Treatment. 2. Methods On a day three times in Mahangjungchentang taken patients who with Ventricular septal defect in the aftermath of the RBBB. We are observed that the main symptoms of change, vital sign, sleep, stool, urine, heart disease. 3. Results Teaumin with asthma, the effect of Mahuang, and the side effects are fewer. The individual effects of herbs are important. but Sasang constitutional effects are important too. 4 Conclusions Mahuang can increase heart disease. But there was a difference among Sasang constitution classification. This has no side effects from Teaumin than other constitutions. If we use Mahuang according to the Sasang constitution classification in clinic. We have an excellent effect on the treatment of asthma.

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