• Title, Summary, Keyword: ATP

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The Effects of Intracellular Monocarboxylates on the ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes

  • Kim, Na-Ri;Han, Jin;Kim, Eui-Yong;Ho, Won-Kyung;Earm, Yung E.
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.5
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    • pp.581-589
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    • 1998
  • A regulating mechanism of the ATP-sensitive potassium channels $(K_{ATP}\;channels)$ is yet to fully explained. This study was carried out to investigate the effects of intracellular application of monocarboxylates (acetate, formate, lactate, and pyruvate) on $K_{ATP}$ channels in isolated rabbit ventricular myocytes. Single channel currents of $K_{ATP}$ channels were recorded using the excised inside-out or permeabilized attached (open-cell) patch-clamp technique at room temperature. Intracellular application of acetate, formate and pyruvate led to an inhibition of channel activity, whereas intracellular application of lactate increased channel activity. These effects were reversible upon washout. Analysis of single channel kinetics showed that monocarboxylates did not affect open-time constant and close-time constant. These results suggest that monocarboxylates participate in modulating $K_{ATP}$ channels activity in cardiac cells and that modulation of $K_{ATP}$ channels activity may resolve the discrepancy between the low $K_i$ in excised membrane patches and high levels of intracellular ATP concentration during myocardial ischemia or hypoxia.

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Analysis of Trial Test for ATP On-board Equipment of Tilting Train (틸팅열차 ATP 차상장치의 시운전시험 분석)

  • Baek, Jong-Hyen
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.10
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    • pp.3911-3916
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    • 2010
  • In this paper we describe contents and results on running test for ATP on-board equipment, which has propelled as one of the research projects, so called, "Reliability assessment and operation technology development for Korean-type tilting trains" in order to ensure the safety and operation efficiency of tilting trains. We developed tilting trains for the speed-up of conventional lines and for the passenger service improvement where the KTX is not available. And we made progress the operation trial test in the 120,000 km distance with the use of ATS equipment, used in existing lines, for the purpose of the reliability assessment of the developed tilting trains. We decided to accelerate the speed for more than 200km/h with respect to the 6 existing lines including Jungang-line and Chungbuk-line where KTX has not operated. According to this decision, Train control system is to be changed from ATS to ATP. We should have installed an ATP on-board unit in tilting trains and verified the operational suitability, therefore we installed the same ATP on-board unit on tilting trains as that used in the ATP construction project on Gyeongbu-line and Honam-line, and verified that the function and performance of the installed ATP on-board unit conformed to the tilting trains operation.

Evidences for Functionally Direct Coupling between Mitochondrial Phosphocreatine Formation and Oxidative Phosphorylation (Oxidative Phosphorylation계에 의한 Phosphocreatine의 생성 기작)

  • Kim, Il-Han
    • The Journal of Natural Sciences
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    • v.5 no.2
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    • pp.3-11
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    • 1992
  • As concentration of ADP was increased, the rate of phosphocreatine formation by respiring heart mitochondria was increased. The value of apparent Km of the phosphocreatine-forming mitochondria for ADP was estimated to be 0.0185 mM. This value was much lower than that of Km for ATP (0.31 mM) which was determined from the reaction of the soluble form of mitochondrial creatine kinase. The concentration of ATP remained constant during the respiring in the presence of ADP. The rate of accumulation of oxidative-phosphorylated ATP in the mitochondrial respiration medium was continuously monitored as a function of ADP concentration with the firefly luciferase-coupled assay. In that case, exogenous creatine did not affect the rate of accumulation of ATP, indicating that phosphocreatine-forming (i.e.,respiring) mitochondria in the presence of ADP did not use the ATP in the medium as a substrate.These results suggest that the heart mitochondrial creatine kinase bound to the inner membrane functionally tight-coupled to the oxidative phosphorylating system with respect to the respired ATP.

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The Study on Train Separation Control Technology using Balise for Conventional Line Speed Up (기존선 속도 향상을 위한 발리스를 이용하는 열차간격제어 기술에 대한 연구)

  • Baek, Jong-Hyen;Lee, Chang-Goo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.2
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    • pp.256-263
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    • 2009
  • KORAIL carries out an improvement project of railway signaling system for the conventional line from the existing method which permits a train to move within limited speed the ground signal of ATS(Automatic Train Stop) system. The proposed system makes possible that a train can be driven using a speed profile created by onboard signaling system(ATP) with the movement authority from ground balise. A driving test over 100,000km is being executed by developing a tilting train for the speed elevation on the conventional line. And, the introduction of the tilting train by ATP system to the Jung-ang line is expected. However, a speed elevation on a curved line section has a restriction. Therefore, research on safety braking model and train separation control technology for the localization of ATP system is required preferentially. In this paper, we presented a safety braking model of ATP system and a train separation control method that use ground balise as variable information provider, and executed a performance simulation.

Effect of Prostaglandins $D_2,\;E_2\;and\;I_2\;on\;the\;Regulation\;of\;K_{ATP}$ Channel Activity in Rat Cardiac Myocytes

  • Ju, Jeong-Min;Nah, Seung-Yeol;Kim, Jae-Ha
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.507-512
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    • 1999
  • Contribution of prostaglandins $D_2,\;E_2\;and\;I_2\;(PGD_2,\;PGE_2\;and\;PGI_2)$ on the regulation of ATP-sensitive $K^+$ channel $(K_{ATP}\;channel)$ was investigated in isolated single rat ventricular cardiac myocytes using the patch clamp technique. $PGD_2,\;PGE_2\;and\; PGI_2$ did not affect $K_{ATP}$ channel activity in the inside-out patch, but increased channel activity in a dose-dependent manner when the channel activities were attenuated by the administration of 100 ${\mu}M$ ATP to the internal solution in the inside-out patch. Channel activations by the prostaglandins were abolished by 50 ${\mu}M$ glibenclamide, a $K_{ATP}$ channel blocker. Dose-response curves of relative channel activity against the ATP concentrations of internal solution in the inside-out patch were shifted to the right in the presence of those three prostaglandins. The rank order of the channel stimulatory potencies $(as\;IC_{50}\;for\;ATP)$ calculated from the dose-response curves were $PGI_2\;>\;PGD_2\;>\;PGE_2.$ Conductance of the channel was not changed by those three prostaglandins. In conclusion, we suggest that prostaglandins $D_2,\;E_2\;and\;I_2$ are involved in the regulation of $K_{ATP}$ channel activity in certain circumstances, and that those three prostaglandins may cause myocardial relaxation by opening $K_{ATP}$ channels, thus protecting the heart from ischema.

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Opening of ATP-sensitive $K^+$ Channel by Pinacidil Requires Serine/Threonine Phosphorylation in Rat Ventricular Myocytes

  • Kwak, Yong-Geun;Chae, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.3
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    • pp.293-303
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    • 1999
  • The influences of specific protein phosphatase and protein kinase inhibitors on the ATP-sensitive $K^+\;(K_{ATP})$ channel-opening effect of pinacidil were investigated in single rat ventricular myocytes using patch clamp technique. In cell-attached patches, pinacidil $(100\;{\mu}M)$ induced the opening of the $K_{ATP}$ channel, which was blocked by the pretreatment with H-7 $(100\;{\mu}M)$ whereas enhanced by the pretreatment with genistein $(30\;{\mu}M)$ or tyrphostin A23 $(10\;{\mu}M)$. In inside-out patches, pinacidil $(10\;{\mu}M)$ activated the $K_{ATP}$ channels in the presence of ATP (0.3 mM) or AMP-PNP (0.3 mM) and in a partial rundown state. The effect of pinacidil $(10\;{\mu}M)$ was not affected by the pretreatment with protein tyrosine phosphatase 1B $(PTP1B,\;10\;{\mu}g\;ml^{-1}),$ but blocked by the pretreatment of protein phosphatase 2A $(PP2A,\;1\;U\;ml^{-1})$. In addition, pinacidil $(10\;{\mu}M)$ could not induce the opening of the reactivated $K_{ATP}$ channels in the presence of H-7 $(100\;{\mu}M)$ but enhanced it in the presence of ATP (1 mM) and genistein $(30\;{\mu}M).$ These results indicate that the $K_{ATP}$ channel-opening effect of pinacidil is not mediated via phosphorylation of $K_{ATP}$ channel protein or associated protein, although it still requires the phosphorylation of serine/threonine residues as a prerequisite condition.

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Effects of Some Heavy Metals(Al, Cd, Hg, and Pb) on ATP Content in Plant Leaves (식물엽의 ATP함량에 미치는 중금속(Al, Cd, Hg 및 Pb)의 영향)

  • 성민웅
    • Journal of Plant Biology
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    • v.22 no.4
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    • pp.107-113
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    • 1979
  • The present study was carried out to estimate the comparative effects of hydroponic heavy metals (Al, Cd, Hg, and Pb) on ATP content in plant leaves grown with Hoagland solution under green house condition. The two plants, kidneybean(Phaseolus vulgaris L.) and buckwheat(Fagopyrum esculentum M nch), showed similar inhibitory effect of heavy metals on ATP content in order of Hg, Cd, Pb, and Al. But the overall inhibitory effect was greater in kidneybean than in buckwheat. The affinity of heavy metals, in vitro, toward the enzyme (luciferin-luciferase) is in order of Hg, Al, Cd, and Pb, similar to that toward ATP. The results showed that the inhibitory effect of heavy metals on ATP hydrolysis is mainly due to the coordination of heavy metals with enzyme than ATP.

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An ATP Quotation System in Supply Chain Management (공급사슬경영에 있어서의 납기 회신 시스템)

  • Sim, Seung-Bae;Han, Joo-Yun;Jeong, Bong-Ju
    • IE interfaces
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    • v.13 no.3
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    • pp.405-415
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    • 2000
  • The accurate quotation of Available-To-Promise (ATP) plays a very important role in enhancing customer satisfaction and fill rate maximization. However, the complexity of Supply Chain structure, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. This paper presents a computerized ATP quotation system in global SCM environments where the worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We modeled the ATP quotation processes with the definition of required data flow and a comprehensive ATP-algorithm was newly developed. The illustrative example shows the efficiency of the proposed system is largely affected by the selection of alternative rules used in ATP-algorithm.

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The Action of ATP on Phospholipase $A_2$Activation in C6 Cells (C6세포에서 phospholipase $A_2$활성에 대한 ATP의 작용)

  • 심상수;김명준;윤신희;김창종;조양혁
    • YAKHAK HOEJI
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    • v.45 no.4
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    • pp.413-418
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    • 2001
  • To investigate action of ATP on ischemia-induced brain injury, we measured phospholipase $A_2$activity and nitric oxide (NO) production in C6 cells. ATP alone did not have any influence on phospholipase $A_2$activity but increased NO production. Glutamate (1 mM) significantly increased phospholipase $A_2$activity whereas did not increased NO production. ATP significantly inhibited phospholipase $A_2$activation induced by 0.1 $\mu$M A23187, 1 mM glutamate and 1 mM $H_2O$$_2$, but did not inhibited 1 $\mu$M PMA-induced phospholipase $A_2$activation. From the above results, it is suggested that the action of ATP in C6 cells has dual actions, such as the inhibition of agonist-induced phospholipase $A_2$activation and the increase of NO production.

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The Study of Installation and Installation Test for Tilting Train ATP On-board Equipment (틸팅열차용 ATP 차상장치의 설치 및 설치시험 연구)

  • Baek, Jong-Hyen
    • Proceedings of the KAIS Fall Conference
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    • pp.119-122
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    • 2010
  • 본 논문에서는 틸팅열차의 안전성 확보 및 운행효율 향상을 위해 "한국형 틸팅열차 신뢰성 평가 및 운용기술개발" 연구과제의 한 분야로 추진된 ATP 차상장치의 설치 및 시운전시험에 대한 내용 및 결과를 제시하고 있다. 한국철도기술연구원에서는 기존선의 속도 향상과 KTX 비수혜지역의 여객 서비스 향상을 위해 틸팅열차를 개발하였으며 개발된 틸팅열차의 신뢰성 평가를 위해 기존에 사용되고 있는 ATS 장치에 의한 10km 주행 시운전 시험을 진행하였다. 국토해양부에서는 KTX가 운행되지 않는 지역인 중앙선 및 충북선을 비롯한 7개 기존 노선을 200km/h 이상으로 고속화하기로 하였으며, 이에 따라 열차제어시스템은 기존의 ATS 장치에서 ATP 장치로 개량하여야 한다. 따라서 틸팅열차에도 ATP 차상장치를 설치하여 운행 적합성을 확인하여야 하기 때문에 한국철도공사의 경부선 및 호남선 ATP 구축사업에 사용된 것과 동일한 ATP 차상장치를 틸팅열차에 설치하여 시험하였다.

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