Ionic Dependence and Modulatory Factors of the Background Current Activated by Isoprenaline in Rabbit Ventricular Cells

Leem. Chae-Hun,Lee. Suk-Ho,So. In-Suk,Ho. Won-Kyung,Earm. Yung-E 대한생리학회 1992 대한생리학회지 Vol.26 No.1

In order to elucidate the properties of the background current whole cell patch clamp studies were performed in rabbit ventricular cells. Ramp pulses of ±80 mV from holding potential of 40 mV(or 20 mV) at the speed of 0.8 V/sec were given every 30 sec(or 10 sec) and current-voltage diagrams(I-V curve) were obtained. For the activation of the background current isoprenaline, adenosine 3 ,5 -cyclic monophosphate(dBcAMP), guanosine 3 ,5 -cyclic monophosphate(cGMP), and N⁶-2 -o-dibutyryladenosine 3 ,5 -cyclic monophosphate(dBcAMP) were applied after all known current systems were blocked with 2mM Ba, 1 mM Cd ,5 mM Ni, 10 μM diltiazem, 10 μm ouabain, and 20 mM tetraethylammonium(TEA). The conductance of background current in control was 0.65±0.69 nS at 0 mV, its I-V curves was almost linear and reversed near 50 mV. When there was no taurine in pipette solution, isoprenaline hardly activated the background current but when taurine existed in pipette solution, isoprenaline activated the larger background current. Cyclic AMP or cyclic GMP alone had little effect on the activation of the background current, while cGMP potentiated cGMP effect. When the background current was activated with cGMP and cAMP, isoprenaline could not further increased the background current. The background current activated by isoprenaline depended on extracellular Cl^- concentration and its reversal potential was shifted according to chloride equilibrium potential. The change of extracellular Na<Sup>+</sup> concentration had little effect on reversal potential of the background current activated by isoprenaline.

Frontier Symposium 4 : System Biology Symposium ; Modelling electrical activity of cardiocyte in pulmonary vein of rabbit

( Chae Hun Leem ),( Jae Boum Youm ),( Won Tae Kim ),( Han Choe ),( Yeon Jin Jang ),( Chun Sik Park ) 한국생화학분자생물학회 (구 한국생화학회) 2004 생화학분자생물학회 춘계학술발표논문집 Vol.2004 No.-

알코올성 간경변 환자에서 위대망 정맥류 출혈로 인한 자발성 혈복강 1 예

채희복,윤세진,박선미,성노현,배일헌,임정묵,장이찬,최기원,신종성,지정훈 대한간학회 2001 Clinical and Molecular Hepatology(대한간학회지) Vol.7 No.3

Portal hypertension often leads to the development of several collateral vessels that shunt blood flow from the portal to the systemic circulation. The rupture of intra-abdominal varix is an unusual complication of portal hypertension that can lead to life-threatening hemoperitoneum of the patient is herrmdynamically unstable due to massive intra-abdominal bleeding, exploratory laparotomy should be performed on the patient. There are several reported cases of intra-abdominal variceal bleeding such as paraumbilical varix, the varix from the small intestine and proximal colon etc. Spontaneous hemoperitoneum caused by the rupture of gastroepiploic vein varix, however, has not been repzted in Korm, to the best of our knowledge. We wiU discuss a patient with portal hypnsion due to liver cirrhosis who pnmented with acute intra-abdominal bleeding. During the laparotomy, he was found to have a rupture of the gastnxpiploic vein. 'Ihe vessel was ligated, and the patient recovered uneventfully by operative variceal ligation. (Korean J Hepatol 2001;7:336-340)

간 정맥폐쇄성 질환 1예

채희복,임정묵,최재홍,장이찬,배일헌,성노현,윤세진 대한내과학회 2002 대한내과학회지 Vol.63 No.6

Veno-occlusive disease of the liver was first reported by Chiari in 1899. Pyrrolizidine-containing substances, chemotherapeutics and hepatic radiation injury can cause this disorder. Bone marrow and renal allograft recipients are at risk for the development of veno-occlusive lesions. Veno-occlusive disease produces a syndrome of painful hepatomegaly, jaundice and fluid accumulation. The disease affects central vein and zone 3 of the liver acinus. We discuss a patient with tender hepatomegaly and high fever due to veno-occlusive lesion. We mis-diagnosed this case as acute cholecystitis because of clinical symptoms and radiological findings of GB wall thickening. During the laparotomy, she was found to have a congested liver and dilatation of superficial lymphatics of the liver surface. The Liver biopsy showed centrilobular congestion and hepatocyte necrosis in acinar zone 3. We could not determine the etiological factor in this patient. We considered that she suffered a mild form of veno-occlusive disease and recovered spontaneously within 1 month.

Pulmonary Function Difference in Sasang Constitutional Types

Yoon, Jiwon,Leem, Chae Hun,Kim, Jong Yeol Hindawi 2018 Evidence-based Complementary and Alternative Medic Vol.2018 No.-

<P>The purpose of this study was to determine the differences in pulmonary function among Sasang constitutional types in young adults. The Sasang Constitutional Analysis Tool (SCAT), pulmonary function tests (PFTs), and cardiopulmonary exercise tests were conducted in 417 participants from 2009 to 2015. Subjects with the Tae-Eum (TE) type had significantly higher inspiratory capacity (IC) and inspiratory reserve volume (IRV) values than those with the So-Yang (SY) and So-Eum (SE) types (<I>P</I> < 0.0001). The TE and SY types showed higher forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV<SUB>1</SUB>) values than the SE type (<I>P</I> < 0.0001). An increase in IRV and a decrease in expiratory reserve volume (ERV) in TE type males remained even after adjusting for covariate factors. These results indicate that young adults with the TE type have weaker lung function than those with the other constitutional types, suggesting its innate physiological pulmonary features.</P>

Effect of Various Divalent Ions on the Calcium Current of Adrenal Medullary Chromaffin Cells in the Rat

Kim, Jun,Leem, Chae-Hun,Kim, Sang-Jeong The Korean Physiological Society 1992 대한생리학회지 Vol.26 No.2

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

Toward a grey box approach for cardiovascular physiome

Minki Hwang,Chae Hun Leem,Eun Bo Shim 대한약리학회 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.5

The physiomic approach is now widely used in the diagnosis of cardiovascular diseases. There are two possible methods for cardiovascular physiome: the traditional mathematical model and the machine learning (ML) algorithm. ML is used in almost every area of society for various tasks formerly performed by humans. Specifically, various ML techniques in cardiovascular medicine are being developed and improved at unprecedented speed. The benefits of using ML for various tasks is that the inner working mechanism of the system does not need to be known, which can prove convenient in situations where determining the inner workings of the system can be difficult. The computation speed is also often higher than that of the traditional mathematical models. The limitations with ML are that it inherently leads to an approximation, and special care must be taken in cases where a high accuracy is required. Traditional mathematical models are, however, constructed based on underlying laws either proven or assumed. The results from the mathematical models are accurate as long as the model is. Combining the advantages of both the mathematical models and ML would increase both the accuracy and efficiency of the simulation for many problems. In this review, examples of cardiovascular physiome where approaches of mathematical modeling and ML can be combined are introduced.

Effect of Cyclic GMP on the Calcium Current in Rabbit Ventricular Myocytes

Han, Jin,Leem, Chae-Hun,Ahn, Chul-Soo,So, In-Suk,Kim, Eui-Yong,Ho, Won-Kyung,Earm, Yung-E The Korean Physiological Society 1993 대한생리학회지 Vol.27 No.2

In order to investigate the effect of intracellular cyclic GMP on calcium current the whole-cell patch clamp technique with internal perfusion method was used in isolated ventricular myocytes of the rabbit. Cyclic GMP, 8-bromo-cyclic GMP, cyclic AMP, isoprenaline and forskolin were perfused into cells and their effects on calcium current were analysed by applying depolarizing step pulses of + 10 mV in amplitude far 300 msec from holding potential of - 40 mV. Not only cyclic AMP $(100\;{\mu}M)$ but also cyclic GMF $(100\;{\mu}M)$ increased the basal calcium current. 8-Bromo-cyclic GMP $(100\;{\mu}M)$, a good stimulator of the cyclic GMP-dependent protein kinase, also increased the basal calcium current and its peak amplitude of calcium current was larger than that in the presence of cyclic AMP or cyclic GMP alone. In the presence of $100\;{\mu}M$ cyclic GMP or $100\;{\mu}M$ 8-bromo-cyclic GMP, already augmented calcium current was potentiated by intracellular application of $100\;{\mu}M$ cyclic AMP or $1\;{\mu}M$ isoprenaline or $1\;{\mu}M$ forskolin. In the presence of cyclic GMP, acetylcholine reduced the calcium current only when the calcium current was increased by isoprenaline. From the above results it could be concluded that intracellular perfusion with cyclic GMP increases the basal calcium current via a mechanism involving a cyclic GMP-dependent protein kinase.

Toward a grey box approach for cardiovascular physiome

Hwang, Minki,Leem, Chae Hun,Shim, Eun Bo The Korean Society of Pharmacology 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.5

The physiomic approach is now widely used in the diagnosis of cardiovascular diseases. There are two possible methods for cardiovascular physiome: the traditional mathematical model and the machine learning (ML) algorithm. ML is used in almost every area of society for various tasks formerly performed by humans. Specifically, various ML techniques in cardiovascular medicine are being developed and improved at unprecedented speed. The benefits of using ML for various tasks is that the inner working mechanism of the system does not need to be known, which can prove convenient in situations where determining the inner workings of the system can be difficult. The computation speed is also often higher than that of the traditional mathematical models. The limitations with ML are that it inherently leads to an approximation, and special care must be taken in cases where a high accuracy is required. Traditional mathematical models are, however, constructed based on underlying laws either proven or assumed. The results from the mathematical models are accurate as long as the model is. Combining the advantages of both the mathematical models and ML would increase both the accuracy and efficiency of the simulation for many problems. In this review, examples of cardiovascular physiome where approaches of mathematical modeling and ML can be combined are introduced.

ABSOLUTELY STABLE EXPLICIT SCHEMES FOR REACTION SYSTEMS

Lee, Chang-Ock,Leem, Chae-Hun,Park, Eun-Hee,Youm, Jae-Boum Korean Mathematical Society 2010 대한수학회지 Vol.47 No.1

We introduce two numerical schemes for solving a system of ordinary differential equations which characterizes several kinds of linear reactions and diffusion from biochemistry, physiology, etc. The methods consist of sequential applications of the simple exact solver for a reversible reaction. We prove absolute stability and convergence of the proposed explicit methods. One is of first order and the other is of second order. Numerical results are included.