• Title/Summary/Keyword: Cardiac activity

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Effects of ${\alpha}-,\;{\beta}-Adrenergic$, and Calcium Channel Blockers on Renin- Angiotensin System in Perfused Rat Heart

  • Park, Chang-Gyo
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.1
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    • pp.55-62
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    • 1998
  • ${\alpha},\;{\beta}-Adrenergics$, and calcium channels were known to be related to inducing cardiac hypertrophy. Recently, it was reported that the cardiac renin-angiotensin system (RAS) was an important factor in ventricular hypertrophy. The present study was aimed to investigate the effects of ${\alpha},\;{\beta}-adrenergic$, and calcium channel blockers that might be involved in the regulation of cardiac RAS. The reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of renin gene in the perfused rat heart. Changes in angiotensin converting enzyme (ACE) activity and cyclic AMP (cAMP) content which were thought to play a role in inducing cardiac hypertrophy were measured in the perfused rat heart. The expression of renin gene was not only increased by isoproterenol with metoprolol-pretreatment but also increased by vasopressin treatment in the presence of calcium channel blocker, nifedipine or verapamil. Either prazosin alone or norepinephrine with prazosin-pretreatment significantly increased the ACE activity. However, isoproterenol with metoprolol-pretreatment significantly decreased the ACE activity. On the other hand, the ACE activity was not changed by vasopressin, nifedipine, or verapamil treatments. The content of cAMP was significantly increased by either isoproterenol or vasopressin treatment. According to these results, renin gene expression was associated with ${\beta}2$ - adrenoceptor and calcium channel. ACE activity was associated with ${\alpha}-\;and{\beta}2$ - adrenoceptor. In conclusion, ${\beta}2$ - adrenoceptor was important in cardiac renin gene expression and ACE activity and ${\alpha},\;{\beta}$ -adrenergic, and calcium channel blockers might be involved in the regulation of cardiac RAS in a complicated way.

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Cardiac Development and Cell Cycle

  • Koh, Keum-Nim;Lee, Seog-Jae;Lee, Ho-Keun;Ahn, Ji-Eun;Kim, Jae-Chol;Ha, Ki-Chan;Chae, Soo-Wan;Koh, Gau-Young
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.13-13
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    • 1998
  • The molecular mechanisms that arrest cardiomyocytes in the cell cycle during postnatal period remain largely unknown. The activity of CDKs control cell cycle progression, and this activity is regulated positively and negatively by association of CDKs with cyclins and cyelin dependent kinase inhibitors (CKIs) respectively.(omitted)

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Clinical Application of I-123 MIBG Cardiac Imaging (I-123 MIBG Cardiac SPECT의 임상적 적응증)

  • Kang, Do-Young
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.5
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    • pp.331-337
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    • 2004
  • Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MIBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with I-123 MIBG imaging nay be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy.

Relationship between ambulatory blood pressure monitoring and cardiac function (보행 혈압 측정과 심장 기능의 관계)

  • Song, Young-Hwan
    • Clinical and Experimental Pediatrics
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    • v.52 no.7
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    • pp.752-755
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    • 2009
  • It is well known that hemodynamic load is one of the most important determinants of cardiac structure and function. Circadian variations in blood pressure (BP) are usually accompanied by consensual changes in peripheral resistance and/or cardiac output. In recent years, reduction in circadian variations in BP and, in particular, loss of nocturnal decline of BP were observed in hypertensive patients with left ventricular hypertrophy (LVH). The patients with only a slight or no loss of nocturnal decline of BP were considered "non-dippers". Regression of LVH was observed after prolonged antihypertensive therapy. Restoration of the circadian rhythm of BP was also observed. However, the classification of patients into "dippers" and "non-dippers" is arbitrary and poorly standardized and repeatable, and in the recent studies, most hypertensive patients with LVH were "dippers". Therefore, we should be particularly cautious about the conclusions drawn using this index. On the other hand, reduced activity of low-pressure cardiopulmonary baroreceptors and impaired day-to-night modulation of autonomic nervous system activity were observed in patients with only LVH. Therefore, alterations in cardiac structure may impair BP modulation. On the other hand, the reverse can also be trueprimary alterations in BP modulation, through a persistently elevated afterload, can increase cardiac mass. Thus, the interrelationship between cardiac structure and BP modulation is complex. Hence, new and more specific methods of evaluating circadian changes in BP are needed to better clarify the abovementioned reciprocal influences.

Metformin Inhibits Isoproterenol-induced Cardiac Hypertrophy in Mice

  • Cha, Hye-Na;Choi, Jung-Hyun;Kim, Yong-Woon;Kim, Jong-Yeon;Ahn, Myun-Whan;Park, So-Young
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.377-384
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    • 2010
  • The present study examined whether metformin treatment prevents isoporterenol-induced cardiac hypertrophy in mice. Chronic subcutaneous infusion of isoproterenol (15 mg/kg/24 h) for 1 week using an osmotic minipump induced cardiac hypertrophy measured by the heart-to-body weight ratio and left ventricular posterior wall thickness. Cardiac hypertrophy was accompanied with increased interleukin-6 (IL-6), transforming growth factor (TGF)-${\beta}$, atrial natriuretic peptide (ANP), collagen I and III, and matrix metallopeptidase 2 (MMP-2). Coinfusion of metformin (150 mg/kg/24 h) with isoproterenol partially inhibited cardiac hypertrophy that was followed by reduced IL-6, TGF-${\beta}$, ANP, collagen I and III, and MMP-2. Chronic subcutaneous infusion of metformin did not increase AMP-activated protein kinase (AMPK) activity in heart, although acute intraperitoneal injection of metformin (10 mg/kg) increased AMPK activity. Isoproterenol increased nitrotyrosine levels and mRNA expression of antioxidant enzyme glutathione peroxidase and metformin treatment normalized these changes. These results suggest that metformin inhibits cardiac hypertrophy through attenuating oxidative stress.

Knowledge and Learning Needs of Coronary Artery Bypass Graft Patients on Cardiac Rehabilitation (관상동맥 우회술(CABG)환자의 심장재활에 대한 지식과 교육 요구도 조사)

  • Lee, Jung-Sook;Choe, Myoung-Ae
    • Journal of Korean Biological Nursing Science
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    • v.9 no.1
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    • pp.5-31
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    • 2007
  • Purpose: The purpose of this study was to explore the knowledge and learning needs on cardiac rehabilitation of coronary artery bypass graft(CABG) patients. Method: The subjects consisted of 100 CABG patients at A hospital in Seoul. Data were collected by the two different kind of questionnaires which measure knowledge and learning needs on cardiac rehabilitation of CABG patients. The subjects responded the questionnaire on knowledge before CABG and that on learning needs before their discharge. Result: The mean score of knowledge on cardiac rehabilitation was 68.54. Knowledge on risk factor, nature of disease, diet, daily activity, medication, post operative care were great in order. The mean score of learning needs on cardiac rehabilitation was 4.28. Learning needs on diet, medication, nature of disease, post operative care, daily activity, risk factor were great in order. There were significant differences in knowledge according to occupation, economic status and family history(p=.021, p=.017, p=.023). There was a positive correlation between knowledge and learning needs(r=.3009, p=.002). Conclusion: Level of knowledge on cardiac rehabilitation of CABG patients is low and knowledge on postoperative care is the lowest, and learning needs are great in ail categories.

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Effect of lead on mitochondrial activity in rat tussues (랫드의 조직 mitochondria 활성에 대한 납 투여의 영향)

  • Cho, Jong-hoo;Kwon, Oh-deog;Lee, Joo-mook
    • Korean Journal of Veterinary Research
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    • v.36 no.3
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    • pp.565-570
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    • 1996
  • Cardiac, hepatic and renal mitochondria in rats fed lead containing diets were isolated and their activities were studied in terms of NADH oxidation. In normal rats, cardiac and renal mitochondria had similar activities and showed activity values of higher than those in hepatic mitochondria. Cardiac mitochondiral activities in rats fed lead containing diets were increased after 4 weeks of feeding but decreased to activity values close to normal. Renal mitochondrial activities showed a trend of inhibition in all groups fed lead containing diets but were no differenes by feeding periods of 4 and 8 weeks. Feeding of lead containing diets could not be attributed to any changes in the hepatic mitochondrial antivities at experimental doses during 4~8 weeks.

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Screening of the Positive Inotropic Activity of Medicinal Plants Used in Oriental Medicine

  • Choi, Deok-Ho;Kang, Dae-Gil;Kim, Seung-Ju;Cui, Xun;Lee, Ho-Sub
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.3
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    • pp.730-734
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    • 2006
  • Aqueous extracts of medicinal plants traditionally used in the East Asia such as China, Korea, and Japan were screened for inotropic activity using isolated rabbit atria. Among the twenty-one aqueous-extracts from medicinal plants, the aqueous extracts of Convallaria keiskei(ACK) and rhizome of Coptis chinesis (ACC) were found to exhibit distinctive positive inotropic activity. The aqueous extracts of C. keiskei and rhizome of C. chinensis significantly increased atrial stroke volume and pulse pressure in beating rabbit atria. These findings suggest that the aqueous extracts of C. keiskei and rhizome of C. chinensis enhance the cardiac muscle contractility and then could be useful for the treatment of cardiac failure.

Right Atrial Free Wall Rupture due to Blunt Cardiac Trauma - A Case Report - (외상성 우심방 파열 1례 보)

  • 김요한
    • Journal of Chest Surgery
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    • v.20 no.2
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    • pp.427-431
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    • 1987
  • A case is presented of a steering wheel Injury to the chest which developed right atrial free wall rupture and cardiac tamponade without rib fractures or hemo-pneumothorax. A 30 year old man who sustained, blunt chest trauma by steering wheel injury to his chest developed right atrial rupture and cardiac tamponade. Pericardiocentesis was performed and cardiac tamponade was confirmed. After a median sternotomy, large right atrial free wall laceration [about 8cm] was noted. He was placed on cardiopulmonary bypass. The laceration wound of right atrium was closed with a 2 rows of continuous suture. Recovery was uneventful. The patient has returned to his previous level of activity.

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Comparison of Acute Cardiovascular Effects of Using Heated Tobacco Productsand Cigarette Smoking (가열담배 사용과 연소담배 흡연의 급성 심혈관 효과 검증)

  • Dong Kyu Kim;Maeng Kyu Kim
    • Journal of Life Science
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    • v.34 no.5
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    • pp.320-332
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    • 2024
  • The aims of this study were to compare the differences in hemodynamics between cigarette smoking and using heated tobacco products (HTPs) and to determine the acute effects of using HTPs on cardiac autonomic regulation. Another goal was to examine the acute cardiac autonomic responses when using different tobacco sticks in HTPs. Sixteen healthy male smokers completed an open-label, randomized, crossover trial consisting of non-smoking (NS), cigarette smoking, and the use of two different HTPs (IQOS with HEETS; lil SOLID with Fiit). Sub-trials, which included NS, lil SOLID with Fiit, and lil SOLID with HEET, were performed on eight smokers among the total subjects. Hemodynamic variables, such as systolic blood pressure (SBP) and diastolic blood pressure (DBP), and heart rate variability were measured before, during, and 30 minutes after using each tobacco product. Using HTPs resulted in a significant increase in both SBP and DBP, comparable to smoking cigarettes. Cardiac sympathetic activity significantly increased, and cardiac vagal tone (CVT) significantly decreased after acute exposure to HTP aerosol, similar to the effects of cigarette smoke exposure. Furthermore, differences in the withdrawal of CVT were observed when using different tobacco sticks in the same HTPs. The findings of this study indicate that acute exposure to HTP aerosol increases the hemodynamic burden and disrupts cardiac autonomic balance, similar to exposure to cigarette smoke. Moreover, depending on the type of tobacco stick inserted into the HTP device, acute withdrawal of CVT may have been enhanced.