• The Korean Journal of Physiology and Pharmacology
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• 제2권5호
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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.

• Preventive Nutrition and Food Science
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• 제11권2호
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• pp.155-159
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• 2006

Models capable of predicting the product quality of mixed apple and carrot retentates (MACR) have been developed using response surface methodology and used to characterize the effects of processing conditions including average transmembrane pressure (ATP), temperature, and blend ratio. Color, soluble solids, total sugar, vitamin C, acidity, turbidity, and viscosity were used to assess the product quality following the ultrafiltration (UF) process. $L^*-value$ decreased with increased ATP, but the value was not affected by changes in temperature. Blend ratio also greatly influenced the $L^*-value$. Redness ($a^*-value$), on the other hand, was less affected by temperature and ATP. As the ATP and temperature increased, yellowness increased gradually. Soluble solids contents appeared to decrease gradually as the ATP increased for all blend samples, but the effect of temperature seemed to be less. Total sugar content was more affected by temperature than ATP. In general, samples containing 75% carrot had higher amounts of vitamin C regardless of processing conditions. Changes in acidity were also complex and appeared to respond to interactions among ATP, temperature, and blend ratio. Turbidity increased for all samples as both ATP and temperature increased. The higher the amount of carrot in the blend samples, the higher values for turbidity. Although the changes were small, viscosity appeared to increase as the ATP and temperature increased during UF.

• 한국동물위생학회지
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• 제19권2호
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• pp.154-162
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• 1996

The effcets of adenosine 5'-triphosphate(ATP) were investigated on the uterine smooth muscle motility in the pig. The results were summarized as follows: 1. The effects of the porcine uterine smooth muscle and the contractile responses increased between the concentration of ATP $10^{-5}$ and $10^{-3}$ M with a dose-dependent manner. 2. The contractile response induced by ATP($10^{-4}$ M) was not blocked by pretreatment with cholinergic receptor blocker, atropine ($10^{-6}$ M) 3. The contractile response induced by ATP ($10^{-4}$ M) was not blocked by pretreatment with $\alpha$ -adrenergic receptor blocker, phentolamine(10$^{-6}$ M) and ${\beta}$-adrenergic blocker, propranolol ($10^{-6}$ M). 4. The contractile response induced by ATP($10^{-4}$ M) was not appeared in 4Ca^{++}$ -free medium. As the concentration of $Ca^{++}$ in $Ca^{++}$ -free medium was increased, the contractile response induced by ATP ($10^{-4}$ M) was enhenced but was completely inhibited by pretreatment with $Ca^{++}$ -channel blocker, papaverine($10^{-6}$ M) or verapamil($10^{-6}$ M). From these results, it was conclued that the effects of ATP were the contraction mediated by purinergic receptor in uterine smooth muscle of pig.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.30-35
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• 1993

E.coli에서 발견된 ATP-dependent 효소인 Clp효소 중에서 Clp A의 ATPase 활성에 대한 영향을 검토하였다. Clp효소의 limiting amount으로 나타난 specific 활성은 일정하게 증가하는 효소의존성을 보였다. ATPase 활성을 나타내고 있는 ClP A는 casein에 의하여 활성화되어지며 2분자의 ATP가 결합하고 ATPase 활성을 나타내기 위한 ATP의 분해는 Clp효소의 단백질 분해 활성에 필요하다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.19-19
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• 2003

We have developed a cardiac cell model (Kyoto Model) for the sinoatrial node and ventricle, which is composed of a common set of kinetic equations of membrane ionic currents, Ca$\^$2+/dynamics of sarcoplasmic reticulum and contractile protein. To expand this model by including metabolic pathways, the intracellular ATP metabolism, which is pivotal in cardiac excitation - contraction coupling, was incorporated. ATP consumption by the sarcolemmal Na$\^$+/ pump and the Ca pump in the sarcoplasmic reticulum were calculated with stoichiometry of 3Na:2K:1ATP and 2Ca:1ATP, respectively. ATP consumption by contraction was estimated according to experimental data. Dependence of contraction on ATP and inorganic phosphate was modeled, based on data of skinned cardiac fiber. in production by mitochondrial oxidative phosphorylation was modified from Korzeniewski '||'&'||' Zoladz (2001), and creatine kinase and adenylate kinase reactions were incorporated. ATP dependence of ATP-sensitive K channel and L type Ca channel were also included.

• 대한수의학회지
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• 제36권4호
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• pp.887-894
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• 1996

Cyclopiazonic acid(CPA) known as stimulating the release of intracellular calcium, aflatoxin $B_1(AFB_1)$ causing gastrointestinal hemorrhage frequently were used as model toxic mycotoxins in these studies. First of all, the effects of various mycotoxins on the platelet aggregation response were determined. The effects of mycotoxins on the ATP release from platelet by aggregating factors were investigated. The results and conclusions obtained from these studies are : 1) CPA promoted ADP, collagen, thrombin, A.A. and PAF-induced rabbit platelet aggregation. $AFB_1$ inhibited collagen, A.A. and PAF-induced rabbit platelet aggregation only. 2) CPA increased both aggregation and disaggregation time, whereas $AFB_1$ decreased in a dose dependent manner. 3) CPA increased ADP, thrombin, A.A. and PAF-induced ATP release. $AFB_1$ increased A.A.-induced ATP release and decreased PAF-induced release in a dose dependent manner. In conclusion, CPA promoted platelet aggregation by the increase of ATP. Antiaggregating effects of AFB1 may be due to decreases of ATP. These data provide the basis for the future study of roles of ATP release in platelet aggregation.

• 한국산학기술학회논문지
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• 제11권10호
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• pp.3911-3916
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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 시운전시험에 대한 내용 및 결과를 제시하고 있다. 기존선의 속도 향상과 KTX 비수혜지역의 여객 서비스 향상을 위해 틸팅열차를 개발하였으며 개발된 틸팅열차의 신뢰성 평가를 위해 기존에 사용되고 있는 ATS 장치에 의한 12만 km 주행 시운전 시험을 진행하였다. KTX가 운행되지 않는 지역인 중앙선 및 충북선을 비롯한 6개 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 경부선 및 호남선 ATP 구축사업에 사용된 것과 동일한 ATP 차상장치를 틸팅열차에 설치하여 시운전 시험을 수행하였으며 설치된 ATP 차상장치의 기능 및 성능이 틸팅열차의 운행에 적합함을 확인하였다.

• 한국산학기술학회논문지
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• 제10권2호
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• pp.256-263
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• 2009

한국철도공사에서는 기존선의 신호시스템을 지상의 ATS 시스템에 의한 신호 현시에 따라 운전자가 제한속도 이내로 열차를 운전하던 방식에서 지상의 발리스로부터 이동권한을 전송받아 차상신호시스템(ATP)에서 Speed Profile을 생성하여 운전하는 Bombardier Transport사의 ATP 시스템으로 개량하고 있다. 한국철도기술연구원에서는 기존선의 속도 향상을 위해 틸팅열차를 개발하여 10만 km 주행시험 중이며, 중앙선에 투입이 가시화되고 있다. 이러한 틸팅열차를 ATP 시스템에 의해 운전할 때 곡선구간에서 현재 제한되어지고 있는 곡선부 통과 속도를 증속하는 것이 쉽지 않은 형편이다. 따라서 향후 ATP 시스템의 국산화 개발이 이루어질 것을 대비하여 선행적으로 ATP 시스템의 핵심 기술인 선행열차에 따른 후행열차의 안전제동모델 및 열차간격제어 기술을 연구 개발할 필요성이 있다. 본 논문에서는 이를 위하여 발리스를 이용하는 ATP 시스템의 안전제동모델 및 열차간격제어 기술을 개발하고 그 성능을 시뮬레이션 하였다.

• 자연과학논문집
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• 제5권2호
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• pp.3-11
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• 1992

ADP 농도를 증가시킴에 따라 미토콘드리아에 의한 Phosphocreatine의 생성속도는 포화 경향을 보이면서 증진되었다. 이 조건에서 Phosphocreatne 생성 속도를 측정하여 가해준 ADP에 대한 Km값을 구해본 결과 0. 0185 mM 임을 알았고, 이 Km값은 미토콘드리아의 Oxidative Phosphoryla-tion게와 연계되지 않은 (추출한) 미토콘드리아 Creatine Kinase의 ATP에 대한 Km 값인 0. 21mM보다 훨씬 낮음을 알 수 있었다. 이 외에도 ADP 존재하에 Oxidative Phosphorylation에 의한 ATP 생성에 대한 Creatine Kinase의 활성의 영향을 살펴본 결과 이 조건에서 Phosphocreatine은 반응시간에 정비례하게 생성 되었으나, 생성된 ATP는 반응시간에 무관함을 보였다. 또한 Oxidative Phosphorylation에 의해 미토콘드리아 외부 Respiration 용액 내에 이 ATP가 축적되는 속도도 미토콘드리아 Creatine Kinase의 Phosphocreatine 생성과 무관함을 알수 있었다. 이상의 결과들은 Mitochondrial Creatine Kinase가 Oxidative Phosphorylation계와 기능적으로 밀접하게 연계되어 ATP가 아닌 Phophocreatine이 에너지 전달 물질로 직접 이용될 가능성을 시사해준다.

• Biomolecules & Therapeutics
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• 제12권1호
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• pp.25-33
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• 2004

In this study we investigated whether ATP loss was involved in the potentiated death of immunostimulated rat primary astrocytes in glucose-deprived condition. Rat primary astrocytes immunostimulated with LPS plus IFN-${\gamma}$ for 48 h underwent death upon glucose deprivation, which dependent on the production of peroxynitrite. Intracellular ATP level synergistically decreased by glucose deprivation in immunostimulated astrocytes but not in control cells, and the loss of ATP occurred well ahead of the LDH release. The synergistic cell death and ATP loss by immunostimulation and glucose deprivation were inhibited by iNOS inhibitor (L-NAME and L-NNA) or peroxynitrite decomposition catalyst (also a superoxide anion scavenger), Mn(III)tetrakis(N-methyl-4'-pyridyl)porphyrin (MnTMPyP). Exogenous addition of peroxynitrite generator, SIN-l timedependently induced ATP loss and cell death in the glucose-deprived astrocytes. Depletion of intracellular glutathione (GSH) and dis겨ption of mitochondrial transmembrane potential (MTP) were also observed under same conditions. Supply cellular ATP by the addition of exogenous adenosine or ATP during glucose deprivation inhibited ATP depletion, GSH depletion, MTP disruption and cell death in SIN-l treated or immunostimulated astrocytes. This study showed that perturbation in the regulation of intracellular ATP level in immunostimulated astrocytes might make them more vulnerable to energy challenging stimuli.