• 대한수의학회지
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• 제36권1호
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• pp.65-74
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• 1996

Atrial Natriuretic Peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties of vascular smooth muscle. Specific chemical modulator responsible for the ANP secretion has not yet been found. Although atrial stretch of stretch-release is to be a major stimulus for the secretion of ANP, the precise mechano-molecular transduction mechanism responsible for its evoked secretion remains to be elucidated. It is interested to clarify the effect of superoxide anion in the stretch-induced ANP secretion. In order to investigate the effectg of $H_2O_2$ in the regulation of ANP secretion, a perfused model of left atrium of rats was used. The results obtained were as follows; 1. The ANP secretion and the extracellular fluid(ECF) translocation were accentuated by the effect of repetitive atrial distension-reduction volume at atrial pressure($4cmH_2O$). 2. The dilution curve showed to be in parallel between pure atriopeptin III (AP III) and perfusated buffer. 3. $H_2O_2(5{\times}10^{-4}M)$ accenturated a strectch-release induced increase of the ANP secretion. The amount of released ANP was significantly(p<0.01) increased. These results suggest that the superoxide anion may be involved in the regulatory mechanism of mechanically activated ANP release.

• Journal of Chest Surgery
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• 제16권3호
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• pp.272-280
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• 1983

With respect to controversial opinions concerning the nitroglycerin effects on cardiac muscle the direct nitroglycerin actions were thoroughly studied in isolated papillary muscles, atrial preparations and coronary strips of rabbits. Isometric active tension of papillary muscles developed at $35^{\circ}C$ upon electric stimulation at a rate of 60/min, was not affected by nitroglycerin up to a concentration of 10mg/L Higher concentrations of nitroglycerin, however, reduced action tension progressively. This depression of mechanical activity is accompanied by a decrease in oxygen consumption as measured by means of a flow respirometer. Resting oxygen uptake, on the other hand, remained unchanged. Similarly active tension of spontaneously beating atrial preparations also declined at a nitroglycerin concentration of more than 10 mg/L, whereas the sinus frequency did not change up to 40 mg/L. In contrast, rabbit coronary strips are much more sensitive to nitroglycerin and relax in a range of 10-100 ug/L of nitroglycerin concentration. The results indicate that the pharmacologic effects of nitroglycerin in coronary disease are due to vascular actions, because the plasma levels of nitroglycerin attainable in human therapy are not sufficiently high to directly influence the myocardium.

• Journal of Chest Surgery
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• 제28권1호
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• pp.42-46
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• 1995

Vertical axillary muscle sparing thoracotomy is newly appeared and excellent alternative method of standard posterolateral thoracotomy.It has many advantages compared to standard posterolateral thoracotomy , less postoperative pain, well preserved thoracic muscle strength, full range of motion of the shoulder girdle and attractive cosmetic results. We performed vertical axillary muscle sparing thoracotomy in 36 patients from November 1993 to July 1994. The ages of the patients ranged from 6 months to 71 years[mean 45.1 years , and the patients consisted of 20 males and 16 females.The preoperative diagnosis were as follows : lung cancer in 17 patients, tbc destroyed lung in 7, bronchiectasis in 3, bullous emphysema in 3 and the others are mediastinal tumor, bronchogenic cyst, lung abscess, empyema, esophageal diverticulum, and CCAM [congenital cystic adenomatoid malformation . The operative procedures were as follows : lobectomy and bilobectomy in 16 patients, segmentectomy in 4, wedge resection in 3, penumonectomy in 7, and the others were open biopsy, lobectomy with diaphragm excision, sleeve right upper lobectomy, decortication, mediastinal mass excision, and esophageal diverticulectomy. We had 6 complications : postoperative bleeding in 2 cases, operative wound infection, arrrhythmia[atrial fibrillation , Horner`s syndrome, hoarseness. The subcutaneous seroma occurred in 4 cases but did not require drainage and relieved within 4 weeks spontaneously. We concluded that vertical axillary muscle sparing thoracotomy could be done in most of all thoracic surgery with safety. Comparing to standard posterolateral thoracotomy vertical axillary muscle sparing thoracotomy has many advantages such as less postoperative pain, well preserved muscle strengths and good cosmetic results.

• 동의생리병리학회지
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• 제20권3호
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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.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.76-76
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• 2003

Pluripotent embryonic stem cells can differentiate into beating cardiomyocytes with proper culture conditions and stimulants via embryo-like aggregates. We describe here the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. mES03 cells growing in colonies were dissociated and allowed to re-aggregated in suspension [embryoid body (EB) formation〕. To induce cardiomyocytic differentiation, cells were exposed to 0.75% dimethyl sulfoxide (DMSO) during EB formation for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EB was plated onto gelatin-coated dishes for differentiation. Spontaneously contracting colonies which appeared in approximately 4~5 days upon differentiation were mechanically dissected, enzymatically dispersed, plated onto coverslips, and then incubated for another 48~72 hrs. By RT-PCR, robust expression of cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta$($\beta$-MHC), cardiac transcription factor GATA4, and skeletal muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaC $h_{sm}$ ) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaCh) were reveled at a low level. In contrast, expression of myosin light chain (MLC-2V) and atrial natriuretic factor (ANF) were not detected during EB formation for 8 days. However, a strong expression of the atrial-specific ANF gene was expressed from day 8 onward, which were remained constant in EB. (cardiac specialization and terminal differentiation stage). Electrophysiological examination of spontaneously contracting cells showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes via 4+/4- protocol displayed biochemical and electrophysiological properties of subpopulation of cardiomyocytes.

• 대한약리학회지
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• 제31권3호
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• pp.279-284
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• 1995

본 연구의 목적은 외부에서 nitric oxide (NO)를 투여 하였을때 심근 수축력, 심박동수의 변화 및 혈관 평활근에 대한 효과를 비교함으로서 NO에 대한 이들 장기의 민감도가 서로 같은지 또는 상이한지를 알아보고자 하였다. 본 실험에서는 PIANO 방법에 의한 근장력의 변화와 아울러 심근에서의 $Ca^{2+}$ current를 측정하였다. 랫트의 심방근에 대한 PIANO $(STZ,\;100\;{\mu}M)$는 심근수축력 및 심박동수에 전혀 변화를 주지 않았지만 혈관 평활근에서는 강한 이완 작용을 나타내었다. 한편, 8-Br-cGMP도 고농도 $(100\;{\mu}M)$에서만 심근 수축력을 억제하였다. 토끼의 심방근세포에서 Whole cell voltage patch clamp를 사용시 bradykinin, SNP, 8-Br-cGMP 및 PIANO는 $Ca^{2+}$ current를 억제하였다. 이러한 사실은 외부에서 공급되는 NO에 대한 심근과 혈관 평활근의 반응에는 민감도의 차이가 있음을 암시하며 더 나아가 심근의 경우에도 NO 반응에는 종 (species)간의 차이와 동일 종이라 하더라도 세포(cell)와 장기(tissue)에 차이가 있을 가능성을 제시하였다.

• Reproductive and Developmental Biology
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• 제30권1호
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• pp.47-52
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• 2006

본 연구는 단위발생유래 생쥐 배아줄기세포(P-mES)지가 체외수정유래 생쥐 배아줄기세포 (mES)와 마찬가지로 기능성 심근세포로 체외 분화되는지를 조사하였다. 각 세포주 P-mES04와 MES03를 4일간 부유 배양하여 배아체 (EB)를 형성한 다음 4일간 DMSO를 추가적으로 처리한 뒤 젤라틴이 코팅된 배양접시에 부착시켰다(4-/4+). P-mES04와 mES03으로부터 수축성 심근세포 생성 여부를 30일간 관찰한 결과, 각각 13일(69.83%)과 22일 (61.3%)에 누적 형성율이 가장 높았다. 면역 세포화학염색 결과, 수축성을 나타내는 P-mES04 세포는 수축성 mES03 세포에서와 같이 근육 특이적인 anti-sarcomeric a-actinin 항체와 심근 특이적인 anti-cardiac troponin I 항체에 염색되는 것을 확인하였다. 또한 RT-PCR 결과, 수축성을 나타내는 P-mES04 세포는 심근특이적인 L-type calcium channel, a1C, cardiac myosin heavy chain a, cardiac muscle heavy polypeptide $7{\beta}$, GATA binding protein 4와 atrial natriuretic factor는 발현하나, 골격근 특이적인 L-type calcium channel, a1S는 발현하지 않아 웅성 성체의 심장세포와 유사한 양상을 보였다. 본 연구의 결과는 단위발생 유래 생쥐 배아 줄기세포를 배아줄기세포의 연구의 대체제로 이용할 수 있음을 보여준다.

• The Korean Journal of Physiology
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• 제20권1호
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• pp.17-29
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• 1986

갑상선 호르몬의 표적기관(target organ) 중의 하나인 심장이 hyperthyroid상태에서 심박동수의 증가, 부정맥 그리고 세포 수들에서 sodium, potassium pump기능이 항진되는 것으로 보고되고 있다. 증진된 Pump기능과 더불어 positive chronotropic effect는 심장의 향도잡이로 알려진 동방결절 과 심방근에 어떤 변화에 의하여 발현되는지 알아보기 위하여 $3{\sim}6$개월령의 토끼 (체중 약 1.5kg내외)에 3,3',5-l-triiodothyronine$(T_3)$을 투여하며 실험적으로 hyperthyroid상태를 유도한 다음 심장세포 내에 유리미세전극을 삽입하여 기록한 결과 다음과 같은 성적을 얻었다. 1) 심박동수는 투여 전(Day 1) $169.0{\pm}28.0\;beat/min(Day\;7)$에서 $264.2{\pm}18.9\;beat/min(Day\;7)$으로 156% 가량 증가되었고 체중은 투여전 체중의 $68.2{\pm}2.0%$로 현저한 감소를 보였다. 2) $T_3$투여군에서 활동전압기간은 $148.0{\pm}29.1\;msec$에서 $107.0{\pm}13.6\;msec$로 감소하여 심박동증가를 반영하였으나 그 외의 활동전압 Parameter에서 대조군과 유의한 차를 관찰할 수 없었다. 3) 세포막에 대한 Potassium ion투과성의 영향을 알아보기 위하여 10, 15, $20mM-K^+\;Tyrode$용액을 사용한 결과 SA node에서 $15mM\;K^+$에서 활동전압 발사가 대조군에 비해 현저하게 감소하였고, 4) Ta 투여군에서 심방근의 안정막전압 탈분극 정도는 15mM(P<0.05), $20mM-K^+Tyrode$용액(P<0.05)에서 대조군보다 유의성있게 낮았다. 5) Sodium, potassium pump기능은 대조군에 비해 동방결절$(13.4{\pm}1.1\;vs.\;19.5{\pm}7.1mV,\;p<0.1)$과 심방근$(15.1{\pm}5.5\;vs.\;25.8{\pm}10.0mV,\;p<0.025)$에서 모두 높은 값을 얻었다. 6) $T_3$에 의한 calcium ion의 영향을 알아보기 위하여 $Ca^{++}\;channel\;blocker$로 $MnCl_2$를 사용한 결과 $T_3$ 투여군의 동방결절은 정상대조군의 것보다 낮은 농도의 $MnCl_2$ 용액에서 흥분성의 감소를 보였다.

• The Korean Journal of Physiology and Pharmacology
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• 제6권4호
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• pp.173-181
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• 2002

The sinoatrial (SA) node is a complex and inhomogeneous tissue in terms of cell morphology and electrical activity. There are two models of the cellular organisation of the sinoatrial node: the gradient and mosaic models. According to the gradient model there is a gradual transition in morphology and electrical properties of SA node cells from the centre to the periphery of the SA node. In the mosaic model, there is a variable mix of atrial and sinoatrial node cells from the centre to the periphery. This review focuses on the cellular organisation of the rabbit sinoatrial node in terms of the expression of connexin (Cx40, Cx43 and Cx45), L-type $Ca^{2+}$ channel and $Na^+-Ca^{2+}$ exchanger proteins. These immunocytochemical data, together with morphological and electrophysiological data, obtained from the intact sinoatrial node and isolated sinoatrial node cells support the gradient model of the cellular organisation of the SA node. The complex organisation of the sinoatrial node is important for the normal functioning of the sinoatrial node: (i) it allows the sinoatrial node to drive the surrounding hyperpolarized atrial muscle without being suppressed by it; (ii) it helps the pacemaker activity of the sinoatrial node continue under a wide range of physiological and pathophysiological conditions; (iii) it helps protect the sinoatrial node from reentrant arrhythmias.

• Archives of Pharmacal Research
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• 제17권3호
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• pp.150-153
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• 1994

Ethanolic extract of Daucus carota (DC) at the dose of 10-100 mg/kg caused a dose-dependent fall in systolic and diastolic arterial blood pressure in nomotensive anesthetized rats. These effects were not blocked by atropine (1 mg/kg) and pretratment with DC did not alter the pressor response to norepinephrine indicating that cardiovascular effects of DC are independent of cholinergic or adrenergic recptors involvement. In spontaneously beating guinea-pig paired atria, DC induced a concentration-dependent (03-5 mg/ml) decrease in force and rate of atrial contractions. In rabbit thoracic aorta, DC caused inhibition of $K^+$-induced contractions at similar concentrations. These results suggest that the extract may exhibit $Ca^{2+}$ channel blocking-like direct relaxant action on cardiac and smooth muscle preperations and this action may be responsible for its hypotensive effect observed in the in vivo studies.