• The Korean Journal of Physiology
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• 제20권2호
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• pp.192-198
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• 1986

dopamine이 십이지장구를 포함한 소장의 운동성에 미치는 영향, cholecystokinin이 dopamine의 작용에 미치는 영향 그리고 이들 작용의 신경성 기전을 알아보고자 다음과 같은 실험을 실시하였다. ether로 마취한 토끼 54마리에서 십이지장구, 십이지장, 공장 그리고 회장을 적출하고 절편(길이 1cm)을 만들어 Krebs-Ringr 용액이 채워진 기록 용기에 넣고 자발적인 등장성 수축을 기록하였다. Krebs-Ringr 용액에는 5% $Co_2$를 함유하는 $O_2$를 계속 공급하였으며, 용액의 온도가 $37^{\circ}C$를 유지하도록 하였다. 자발적 수축이 시작하고 20분이 경과한 다음 dopamine($10^{-4}M$), CCK-8($10^{-8}M$), dopamine($10^{^6}M$)등을 투여하면서 수축성을 관찰하여 다음과 같은 결과를 얻었다. 1) dopamine은 소장의 모든 부위에서 자발적 수축성을 억제하였으며, 이러한 dopamine의 작용은 회장을 제외한 다른 부위에서 tetrodotoxin에 의하여 유의하게 감소하였다. 2) domperidone은 소장의 모든 부위에서 dopamine의 억제작용에 길항적으로 작용하였으며, tetrodotoxin을 전처치하면 회장을 제외한 다른 부위에서 domperidone의 길항작용은 완전히 소실되었다. 3) CCK-8는 소장의 모든 부위에서 dopamine의 작용을 감소시켰으며, tetrodotoxin을 전처치하면 CCK-8의 작용은 유의하게 감소되었다. 이상의 결과로 미루어 보아 dopamine은 십이지장구를 포함한 모든 소장의 수축성을 억제하며, CCK-8는 dopamine의 억제 작용을 감소시키는데, 이러한 작용들은 장관내 신경계를 거쳐서 간접적으로 일어나는 것으로 생각된다.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.145.2-145.2
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• 2000

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.149.1-149.1
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• 2000

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2941-2946
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• 2007

A model of the cardiovascular system coupling cell, hemodynamics and autonomic nervecontrol function is proposed for analyzing heart mechanics. We developed a comprehensive cardiovascular model with multi-physics and multi-scale characteristics that simulates the physiological events from membrane excitation of a cardiac cell to contraction of the human heart and systemic blood circulation and ultimately to autonomic nerve control. Using this model, we delineatedthe cellular mechanism of heart contractility mediated by nerve control function. To verify the integrated method, we simulated a 10% hemorrhage, which involves cardiac cell mechanics, circulatory hemodynamics, and nerve control function. The computed and experimental results were compared. Using this methodology, the state of cardiac contractility, influenced by diverse properties such as the afterload and nerve control systems, is easily assessed in an integrated manner.

• 셀메드
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• 제2권3호
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• pp.21.1-21.8
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• 2012

Heart disease that ultimately leads to heart failure (HF) has been the number one cause of death in the United States as well as in many other countries for over a century. Inotropic therapy utilizing cardiotonics to increase cardiac contractility remains a significant component of the management of HF. However, adverse effects of currently available cardiotonics have been compromising their therapeutic value and often lead to further myocardial dysfunction. Thus, discovery of safe cardiotonics remains a main challenge to improvement of inotropic therapy for HF. This review briefly summarized cellular mechanisms underlying the inotropic action of currently available cardiotonics, newly-developed carditonics and the bark of Terminalia arjuna (TA), a tropical tree used in ayurvedic medicine. The potential of TA bark as a new cardiotonic in inotropic treatment for HF was also discussed.

• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.72-77
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• 2008

The present study was undertaken to determine whether pioglitazone treatment 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. Pioglitazone decreased Rho-kinase activating agonist-induced contraction but not phorbol ester-induced contraction suggesting the least involvement of $Ca^{2+}$-independent thin filament regulation of contractility. Furthermore, pioglitazone decreased thromboxane $A_2$ mimeticinduced phosphorylation of MYPT1 at Thr855, the newly-highlighted site, instead of Thr696. In conclusion, this study provides the evidence and possible related mechanism concerning the vasorelaxing effect of pioglitazone as an antihypertensive on the agonist-induced contraction in rat aortic rings regardless of endothelial function.

• Journal of Yeungnam Medical Science
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• 제34권1호
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• pp.128-131
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• 2017

Mid-ventricular obstruction (MVO) rarely occurs in patients without hypertrophic cardiomyopathy. Increased cardiac contractility may play an important role in causing MVO. We experienced a case of severe chest pain and MVO in a 50-year-old female patient. She had hypertension, diabetes, stroke and peripheral artery disease. Her blood pressure was very high (222/122 mmHg) with severe fluctuation. The transthoracic echocardiography revealed MVO accompanied by hyper-dynamic left ventricular systolic function. We regarded her chest pain and MVO as secondary findings related to other diseases. Coronary angiography and several tests for uncontrolled hypertension were performed, and those evaluations revealed that she had coronary artery disease and hyperthyroidism. We considered that the increase in the myocardial oxygen demand in response to the increase in cardiac contractility and workload associated with hyperthyroidism aggravated her symptoms and MVO. She was treated with methimazole and beta blockers and her symptoms dramatically improved.

• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.31-36
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• 2013

The present study was undertaken to investigate the influence of eupatilin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Eupatilin more significantly relaxed fluoride-induced vascular contraction than thromboxane $A_2$ or phorbol ester-induced contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, eupatilin significantly inhibited fluoride-induced increases in pMYPT1 levels. On the other hand, it didn't significantly inhibit phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the primarily inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1. This study provides evidence regarding the mechanism underlying the relaxation effect of eupatilin on agonist-induced vascular contraction regardless of endothelial function.

• 약학회지
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• 제56권3호
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• pp.180-185
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• 2012

The aim of present study was to investigate the possible influence and related mechanism of alcohol on the arterial contraction. Vascular contraction involves the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in alcohol-induced regulation. We hypothesized that alcohol plays a role in vascular contraction evoked by a vasoconstrictor in rat aortae regardless of endothelial function. Denuded arterial rings from male rats were used and isometric contractions were recorded using a computerized data acquisition system. Interestingly, alcohol at a low concentration (3% v/v) inhibited thromboxane $A_2$ or phorbol ester-induced contraction with endothelial function but at a high concentration (10%) didn't inhibit and rather increased the contraction in the denuded muscle. Therefore, alcohol at a low concentration decreases the contraction and alcohol at a high concentration increases the contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the regulation of contractility. In conclusion, alcohol has some effect on the regulation of contractility regardless of endothelial function.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.109-116
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• 1988

In this paper, principles of impedance tenchinque and relationship between stroke volume and impedance change were theoretically explained. An impedance cardiograph was designed and constructed. Its reproducibility was verified by experiment. Until now, the peak point of dZ/dt waveform, first derivative of impedance change(${\Delta}$Z) , has been detected by software technique requiring considerable time to process. However in this paper its peak point was found using hardware for saving processing time. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution (more than 30%). Hence impedance cardiography was found to be better techique for monitoring stroke volume and myocardial contractility for pre and post operation, and pharmacological studies.