• Title/Summary/Keyword: mechanism of action

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Criterion on Enclosed Die Forging with a Double-Action Link-Type Hydraulic Die Set (복동링크유압식 다이세트를 이용한 폐쇄단조의 폐쇄단조조건)

  • Jun, B.Y.;Park, R.H.;Eom, J.G.;Joun, M.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.391-394
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    • 2006
  • In this paper, a criterion on enclosed die forging with a double action link type hydraulic die set is presented. Operational principle of the die set in enclosed die forging is introduced with emphasis on force transfer from the press and the hydraulic system to the material through links, die components and punches. Force transfer mechanism is examined and three different modes are introduced. Requirements on force equilibrium are applied to the three force transfer modes and a criterion on enclosed die forging with a double action link type hydraulic die set is drawn. The criterion is discussed to minimize forming load.

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The Influence of Imipramine on the Effect of Clonidine in Pithed Rats (뇌척수제거 흰쥐에서 Clonidine효과에 미치는 Imipramine의 영향)

  • Kang, S.C.;Lee, W.S.;Rhim, B.Y.;Hong, K.W.
    • The Korean Journal of Pharmacology
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    • v.20 no.2
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    • pp.7-14
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    • 1984
  • In pithed rats, rising in diastolic blood pressure by clonidine, when intravenously injected, is expressed as the postsynaptic action, and inhibitory action on electrical stimulation-induced tachycardia by clonidine is expressed as the presynaptic inhibitory action. In this study it was aimed to observe the inhibitory effect of imipramine caused by a single and chronic administration on both postsynaptic and presynaptic action of clonidine in pithed rats, and discussed in relation with the mechanism of antidepressant action of imipramine. 1) A rise of diastolic blood pressure by clonidine was not antagonized by prazosin, but by both phentolamine and piperoxan. 2) The inhibition by clonidine of tachycardia which was induced by electrical stimulation was also antagonized by phentolamine and piperoxan, but not by prazosin. 3) The increase in diastolic blood pressure in response to clonidine was inhibited by both a single or chronic administration with imipramine (20 mg/kg). It was more pronounced in the latter. 4) The inhibitory action of clonidine on the tachycardia was markedly inhibited by both types of administration with imipramine, between which there showed little difference. It is concluded that the presynaptic ${\alpha}_2-adrenoceptor$ is rather sensitively affected by a single administration with imipramine, and a long-term imipramine treatment may inhibit both pre- and postsynaptic ${\alpha}_2-adrenoceptors$, simultaneously. Furthermore, it was seemed unlikely that these results provide the evidence :to support the fact that the subsensitivity of presynaptic ${\alpha}_2-adrenoceptor$ may be the mechanism of action of tricyclic antidepressant.

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Action of Anthraquinone on Sodium-Potassium activated -ATPase in Rabbit Red Cell Membrane- (Anthraquinone이 토끼 적혈주막의 NaK ATPase웨 활성도에 대한 작용)

  • Koh, Il-Sup
    • The Korean Journal of Physiology
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    • v.11 no.1
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    • pp.1-9
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    • 1977
  • Action of anthraquinone on the sodium plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated and the experiments were also designed to determine the mechanism of action of anthraquinone on the ATPase activity. The following results were obtained 1. The activity of the NaK ATPase from red cell membrane is inhibited by anthraquinone and the concentration of anthraquinone for maximal inhibition is about 5mM. 2. The ratio of inhibition of NaK ATPase by anthraquinone, with a giving concentration of sodium in the medium, is increased by raising the potassium concentration. 3. The ratio of inhibition of NaK ATPase by anthraquinone, with a given concentration of potassium in the medium, is increased by raising the sodium concentration. 4. The action of anthraquinone on the NaK ATPase activity is inhibited by calcium ions and the ratio of inhibition is increased by small amounts of calcium but almost constant by larger amounts. 5. The inhibitory action of anthraquinone on the NaK ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine or the imidazole group of histidine. 6. The inhibitory action of anthraquinone on the ATPase activity is due to sulfhydryl group or the carboxyl group of the enzyme of NaK ATPase.

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The Action Mechanism of several Ginsenosides in their Regulatory Action on the ACtivities of Adenylate Cyclase and Guanylate Cyclase (몇가지 진세노시드들의 아데닐산 고리화 효소와 구아닐산 고리화 효소의 활동성들에 대한 조절작용에 있어서의 작용 메카니즘)

  • 서기림;문종건
    • Journal of Ginseng Research
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    • v.7 no.2
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    • pp.148-155
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    • 1983
  • The effects of the five ginsenosides on the activities of particulate adenylate cyclase and particulate guanylate cylase of rat brain have been studied. The range of concentrations of ginsenosides were between 10$\mu\textrm{g}$ and 500$\mu\textrm{g}$ per 500${mu}ell$ reaction mixture, Also, the effects of three ginsenosides on the activity of soluble guanylate cylace have been studied in the same range of concentrations as in particulate adenylate cyclase. Only ginsenoside Re has shown the reciprocal feeects when tested with particulated adenylate cyclase and particulate guanylated cyclase. Regulatory action of the several mononucleotides on the activities of adenylate cyclase and guanylate cyclase was examined. Ginsenoside Rd-inhibited adenylate cyclase was activated in great extent by the addition of increasing amount of GMP. On the other hand, ginsenoside Rc-activated guanylate cyclase was inhibited by the addition of increasing amount of AMP and GMP. The fact that the stimulatory action of GMP is observed only with particulated adenylate cyclase but not with soluble suanylate cyclase suggests that the action is membrane-related one. The competitive action was observed between ginsenoside Rb2 and dopamine in their binding to the receptors. This result is clear-cut evidence that the ginsenoside Rb2 binds specifically to $\beta$-adrenergic receptors.

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Effects of the Saponin of Polygalae Radix on the Renal Function and CNS-Depression (원지(遠志) Saponin의 이뇨효과(利尿效果) 및 중추억제작용(中樞抑制作用)에 관한 연구(硏究))

  • Park, Dai-Kyu;Lee, Wan-Ha
    • Korean Journal of Pharmacognosy
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    • v.14 no.4
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    • pp.178-192
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    • 1983
  • Polygalae Radix was used as diuretics, analgesics and expertorants in oriental medicine. The root of Polygala tenuifolia Willd. (Polygalaceae) is comprised saponin (Onjisaponin A,B,C,D,E,F and G) polygalitol, onsitin and sugars. The pharmacological action of crude Polygala-saponin (PS) obtained from the roots are studied. The following results were obtained; 1) The median lethal dose $(LD_{50})$ of PS in mice is presented 71.1mg/kg s.c. and 694. 5mg/kg p.o.. 2) PS demonstrated diuretic action of relatively long acting duration in mice. 3) The diuretic mechanism of PS was found due to inhibitory effect of renal tubular reabsorption of electrolytes and glomerular vascular dilatation. 4) The group, administered simultaneously PS and cefadroxil monobydrate was significantly increased with PS alone group on diuretic action. Synergistic effect cefadroxil monohydrate on the diuretic action of PS seems due to competitive inhibition of plasma protein binding with PS. 5) PS demonstrated analgesic action by the acetic acid stimulating method and Randall-Selitto test in mice. 6) PS presented antipyretic action against febrile treated with the typhoid vaccine. 7) PS was significantly prolonged against the hypnotic duration of pentobarbital in mice. 8) Onset time convulsion and death induced by picrotoxin and strychnine in mice were not delayed. According to the above results, the PS was identified as a pharmacological active component obtained from roots of Polygala tenuifolia Willd.

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Effect of Captopril on Renal Function in Dog (개의 신장기능에 미치는 Captopril의 영향)

  • Ko, Suk-Tai;Lee, Min-Jae
    • YAKHAK HOEJI
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    • v.34 no.2
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    • pp.88-101
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    • 1990
  • Captopril, angiotensin converting enzyme (ACE) inhibitor, when given intravenously in dog, elicited the diuretic action along with the increases of glomerular filtration rates (GFR), renal plasma flow (RPF) and osmolar clearances (Cosm) with no changes of free water clearnces ($C_{H_2O}$), and then captopril produced the enlargement of excretion rates of electrolytes in urine and the reduction of reabsorption rates of electrolytes in renal tubles. Captopril, when given into a renal artery, exhibited no changes of renal function in the experinental kidney, whereas diuretic action with the same mechanism as shown in intravenous captopril in control kidney. Captopril, when injected into a carotid artery, showed increases in rates of urine flow in a small does which did not affect on renal action when it was administered intravenusly. Diuretic action induced by captopril was not influenced by renal artery denervation, propranolol and angiotensin II inhibiters. Above results suggest that captopril produced diuretic action along with renal hemodynamic changes by slight contraction of vas efferense and reduction of reabsorption rate of electrolytes in renal tubules, especilly distal tubules, that may be mediatedby endogenous substances.

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EFFECT OF A NEW POSITIVE INOTROPIC AGENT, YS-49, A NOVEL TETRAHYDROISOQUINOLINE COMPOUND

  • Lee, Y. S.;Park, H. S. Yoon-;K. C. Chang
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.88-88
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    • 1995
  • Tetrahydroisoquinoline (THI) compounds have various pharmacological actions in the cardiovascular system. Recently, we have synthesized 1-${\alpha}$-naphthylmethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, YS 49. In the present study, we evaluated the effect of YS-49 on positive inotropic and chronotropic action using isolated rat heart and on blood pressure and heart rate using anesthesized rabbit. Vasodilating action was also assessed in isolated rat thoracic aorta. YS 49, concentration-dependently relaxed rat aorta precontracted with phenylephrine (PE, 0.3 ${\mu}$M) and high potassium (high K$\^$+/, 65.4 mM). The 50% inhibitory concentration (IC$\sub$50/) of YS 49 in PE-induced and high K$\^$+/-induded contraction was 5.36 ${\mu}$M and 2.52 ${\mu}$M, respectively. In isolated rat atria, YS 49 increased both heart rate and force, and in anesthesized rabbit it decreased blood pressure but increased heart rate. In addition, to know the mechanism of action of the compound, propranolol, nonselective ${\beta}$-antagonist, and phentolamine, ${\alpha}$-blocker, were used. Furthermore, a comparison with the effect of higenamine, trimetoquinol on the vasodilating action in rat thoracic aorta was also made. The action of YS 49 was inhibited by the presence of propranolo, not pentolamine. These results indicate that cardiotonic and vasodilatory action of YS 49 is attributable, at least in part, for ${\beta}$-receptor stimulation.

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Consideration of the Early Action in the GHG Emission Reduction (국내 온실가스 감축의 조기행동 인정 방안)

  • Song, Bo-Yun;Park, Su-Mi;Chung, Jin-Do
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.2
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    • pp.209-213
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    • 2011
  • Enforcement Decree of the Framework Act on Low Carbon, Green Growth for achieving the country's GHG emission reduction goal of 30% was in effect. The remarkable content of the Act is the managements of targets for GHG reduction. So, the entities that have reduced voluntarily have much interest in the recognition of 'early action'. The recognition of early action is necessary to induce the fair competence of business entities and promote the voluntary GHG reduction. The definite and concrete guidance should be prepared. The important principles for this are the environmental integrity and the additionality. Based on this, the early action activities must be restricted to the voluntary, real, permanent, quantifiable, verifiable reduction. In the early action recognition, its credit should be allocated additionally set aside from the GHG target allocation in the national total allowance. Through this, the reward for the early reduction should be realized on market mechanism. The effective period to award the early action should be addressed. This can be the period after the enactment of framework on GHG reduction in effect and before the beginning year of GHG target control. It should be set with flexibility through the collection and consultation of the sector's opinions. The appropriate allowance reserve of early action was estimated as approximately 1~1.5% by using the data from the 'Pilot GHG Emission Trading Program' operated by Ministry of Environment. Also, the concrete and detail guidance to construct the necessary infra which is used to register the related information of early action activities should be prepared.