• The Zoological Society Korea : Newsletter
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• v.18 no.2
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• pp.38-44
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• 2001

전위활성화 칼슘통로를 통한 칼슘이온의 세포 내 유입은 근육수축, 시냅스 전달, 호르몬 분비, 효소의 활성도 및 유전자 발현을 조절한다. 이와 같이 중요한 생리적 기능을 조절하기 때문에 칼슘통로를 대상으로 한 다방면의 연구가 과거 20년간 활발히 진행되어 왔다 칼슘통로는 $\alpha$1, $\alpha$2-$\delta$, $\beta$로 구성되어 있으며, 이 중 $\alpha$1은 칼슘통로의 일반적 특성을 나타내는 기본 구조체이며, $\alpha$2-$\delta$와 $\beta$는 $\alpha$1을 조절하는 보조 기능을 한다. 지금까지 10개의 $\alpha$1 subunits(L-형: $\alpha$1S, $\alpha$1C, $\alpha$1D, $\alpha$1F; non-L-형: $\alpha$1A, a1B, $\alpha$1E; T-형: $\alpha$1G, $\alpha$1H, $\alpha$1I), 4종류의 $\beta$ subunits, 3 종류의 $\alpha$2-$\delta$ subunits가 클로닝되었으며, 이들 클론을 이용한 분자 수준에서의 연구가 활발히 이루어지고 있다. 본 논단에서는 칼슘통로의 구조, 기능 및 조절에 대한 연구가 전기생리학적, 분자생물학적 및 약리학적 방법을 사용하여 어떻게 수행되어왔는지 살펴보고, 최근 연구성과에 대해서도 소개하고자 한다.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.27-36
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• 2010

Objectives : We investigated the role of intracellular calcium chelator, bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid(BAPTA), on the modulation of phosphorylation of the spinal N-methyl-D-aspartate receptor(NMDAR) NR1 and NR2B subunits following electroacupuncture(EA). Methods : Bilateral 2 Hz EA stimulation with 1.0 mA was delivered at those acupoints corresponding to Zusanli(ST36) and Sanyinjiao(SP6) in man via needles for 30min. Results : EA analgesia was reduced by intra-peritoneal injection at a higher dose of BAPTA from termination of EA stimulation. At 60 min after EA treatment, the total number of c-fos-immunostained neurons in each regions of the dorsal horn in the $L_{4-5}$ segments was decreased by BAPTA injection, especially in nucleus proprius. The mean integrated optical density (IOD) of NR1 and NR2B subunits were increased only in superficial laminae of EA-treated rats when compared with normal rats. However, the mean IOD of pNR1 was significantly decreased by BAPTA injection in both the superficial laminae and neck region and pNR2B in the superficial laminae. Western blot analyses confirmed the decreased expression of pNR1 and pNR2B. Conclusions : We concluded that intracellular calcium may well play an important role in EA analgesia by modulating the phosphorylation state of spinal NMDAR subunits.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.83-92
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• 1988

Although the release of lysosomal enzymes from activated PMN leukocyte can be regulated by intracellular cyclic nucleotide levels, other responses of PMN leukocyte according to the binding of neurotransmitters to either ${\beta}$-adrenergic or muscarinic receptors are still not clarified. In addition, the function of PMN leukocyte mediated by ${\alpha}$-adrenergic receptors is uncertain. Atropine, phentolamine and propranolol inhibited calcium uptake, superoxide generation, NADPH oxidase activity and phagocytic activity in activated PMN leukocyte, whereas carbachol and isoproterenol slightly further stimulated the responses of activated cells. Either carbachol or isoproterenol stimulated superoxide generation was inhibited by their antagonists, atropine and propranolol, respectively. The response of activated PMN leukocyte was inhibited by chlorpromazine, verapamil and dantrolene but slightly stimulated by lithium. On the other hand, chlorpromazine and dibucaine did not affect NADPH oxidase activity. Atropine, phentolamine and propranolol suppressed the calcium dependent phagocytic activity. Thus, the results suggest that atropine, phentolamine and propranolol may inhibit superoxide generation in activated PMN leukocyte by the inhibition of calcium influx and by their direct action on the NADPH oxidase system which is associated with autonomic receptors.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.167-181
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• 1991

The present study was an attempt to investigate the effect of forskolin on secretion of catecholamines (CA) evoked by Ach, excess $K^+$, DMPP, McN-A-343 and caffeine from the isolated perfused rat adrenal glands and to elucidate its mechanism of action. The perfusion with forskolin (1.0 uM) for 1 min into the adrenal vein enhanced markedly the secreation of CA evoked by Ach (50 ug), excess $K^+$ (56 mM) DMPP (100 uM) and by caffeine (0.3 mM) but did not that by McN-A-343. Forskolin alone did not potentiate the CA secretion. Moreover, forskolin augmented the CA release evoked by the above same stimulation even in the absence of extracellular calcium. The 1 min perfusion of 300 uM-dibutyryl cyclic AMP (DBcAMP), which is known to increase cyclic AMP levels, led to enhancement of Ca secretion evoked by Ach, excess $K^+$ and DMPP but did not that by McN-A-343 and caffeine. DBcAMP by itself also did not augment the CA secretion. In the calcium-free medium DBcAMP significantly enhanced the CA secretion by the same stimulation, except for the case of McN-A-343. These experimental results suggest that forskolin activates adenylate cyclase, resulting the elevation of cyclic AMP which may potentiate cholinergic nicotinic receptor-mediated and also depolarization-dependent CA secretion and that it may alter the intracellular calcium homeostasis in the rat adrenal glands.

• Journal of Veterinary Clinics
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• v.18 no.2
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• pp.93-97
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• 2001

병원성 Mycoplasma hyopneumoniae strain 91-3, 비병원성 M. hyopneumoniae 그리고 M. flocculare를 돼지의 기관지섬모상피에 투여시 세포내 $Ca^{2+}$ 농도 [$Ca^{2+]}$$_{i}$ 의 변화를 본 연구에서 조사하였다. M. hyopneumoniae strain 91-3 (300-$\mu\textrm{g}$ml)를 투여시 기관지 섬모상피내의 $Ca^{2+}$가 투여전과 비교시 투여 후 250$\pm$19 nM (net increase)증가하였다 (10회 반복 47 cells). 이와는 대조적으로 비병원성 M. hyopneumoniae (300 $\mu\textrm{g}$ml) (6회 반복 18 cells)와 M. flocculare (300 $\mu\textrm{g}$ml) (8회 반복 24 cells)는 세포내 $Ca^{2+}$의 농도를 증가시키지 못하였다. 위의 결과로 병원성 M. hyopneumoniae 91-3 균주는 비병원성 mycoplasma와는 다르게 돼지의 섬모상피에서 [$Ca^{2+}$]$_{i}$ 을 유도하였으며 이러한 특성은 mycoplasma 감염증 치료에 중요한 단서를 제공할 뿐만 아니라 새로운 치료법의 개발에 유용한 스크리닝 기술에 응용될 것으로 기대된다.

• The Korean Journal of Zoology
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• v.36 no.4
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• pp.529-534
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• 1993

흰쥐의 신피질 세포막과 소포체 막을 분리하여 카드를 및 Metallothioneln(MT)을 투여하였을 때 세포막에 존재하는 Ca-ATPase에 미치는 영향을 측정하여 다음과 같은 결과를 얻었다. 전기영동상에서 분리된 MT가 분자량 12KD 정도의 위치에 band가 나타났으며, 분리한 각 세포의 막에 카드윰을 농도별로 처리하였을 때 고농도일수록 Ca-ATPase의 활성도가 감소하였으나, MT를 처리한 경우 신피질 세포막은 거의 대조군과 유사한 결과를 나타냈고, 소포체 막에 MT를 처리한 경우는 20mg/ml의 카드윰을 처리한 경우와 유사하였다. 이와같은 결과로 보아 카드윰은 세포막의 Ca-ATPase의 활성을 저하시켜 세포내 칼슘 항상성에 영향을 미치는 MT는 Ca-ATPase의 활성을 회복시켜 카드뮴에 의한 세포독성의 방어작용에 부분적으로 작용한 것으로 생각된다.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.399-415
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• 1999

From bacteria to mammalian cells, one of the most important mediators of intracellular signal transduction mechanisms which regulate a variety of intracellular processes is free calcium. In salivary acinar cells, elevation of intracellular calcium concentration ($[Ca^{2+}]_i$) is essential for the salivary secretion induced by parasympathetic stimulation. However, in addition to $[Ca^{2+}]_i$, gap junctions which couple individual cells electrically and chemically have also been reported to regulate enzyme secretion in pancreatic acinar cells. Since the plasma membrane of salivary acinar cells has a high density of gap junctions, and these cells are electrically and chemically coupled with each other, gap junctions may modulate the secretory function of salivary glands. In this respect, I planned to investigate the role of gap junctions in the modulation of salivary secretion and $[Ca^{2+}]_i$, using mandibular salivary glands of rats. In order to measure the salivary flow rate, fluid was collected from the cannulated duct of the isolated perfused rat mandibular glands at 2 min intervals. $[Ca^{2+}]_i$, was measured from the cells loaded with fura-2 by spectrofluorometry. The results obtained were as follows: 1. CCh-induced salivary secretion was reversibly inhibited by 1 mM octanol, a gap junction blocker. 2. CCh-induced increase in $[Ca^{2+}]_i$, was also reversed by the application of 1 mM octanol. 3. Octanol did not block the initial increase in $[Ca^{2+}]_i$ caused by CCh, which suggested that the reduction of $[Ca^{2+}]_i$, caused by gap junction blockade was not resulted from the inhibition of $Ca^{2+}$ release from intracellular $Ca^{2+}$ stores. 4. Addition of octanol during stimulation with $1{\mu}M$ thapsigargin, a potent microsomal ATPase inhibitor, reduced $[Ca^{2+}]_i$, to the basal level. This suggested that inhibition of gap junction permeability closed plasma membrane $Ca^{2+}$ channels. 5. 2,5-di-tert-butyl-1,4-benzohydroquinone (TBQ) generated $[Ca^{2+}]_i$ oscillations resulting from periodic influx of $Ca^{2+}$ via plasma membrane. The TBQ-induced $[Ca^{2+}]_i$ oscillations were stopped by the application of 1mM octanol which implicated that gap junctions modulate the permeability of plasma membrane $Ca^{2+}$ channels. 6. Glycyrrhetinic acid, another well known gap junction blocker, also inhibited CCh-induced salivary secretion from rat mandibular glands. These results suggested that gap junctions play an important role in the modulation of fluid secretion from the rat mandibular glands and this was probably due to the inhibition of $Ca^{2+}$ influx through the plasma membrane $Ca^{2+}$ channels.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.168-175
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• 2000

Relatively little is known about the signaling mechanism of ginseng saponins (ginsenosides), active ingredients of ginseng, in non-neuronal cells. Here, we describe that ginsenosides utilize a common pathway of receptor-mediated signaling pathway in Xenopus oocytes: increase in intracellular $Ca^{2+}$ concentration via phospholipase C (PLC) and $Ca^{2+}$ mobilization. Ginsenosides induced a marked and robust artivation of $Ca^{2+}$-activated Cl- channels in Xenopus oocytes. The effect of ginsenosides was completely reversible, in a dose-dependent manner with EC$_{50}$ of 4.4 $\mu\textrm{g}$/mi, and specifically blocked by niflumic acid, an inhibitor of $Ca^{2+}$-activated Cl- channel. Intracellular injection of BAPIA abolished the effect of ginsenosides. Intracellular injection of GTP${\gamma}$S also abolished the effect of ginsenosides. The effect of gin senosides on $Ca^{2+}$-activated Cl- currents was greatly reduced by the intracellular injection of heparin, an IP$_3$ receptorantagonist or the pretreatment of PLC inhibitor. These results indicate that ginsenosides activate endogenous $Ca^{2+}$-activated Cl- channels via the activation of PLC and the release of $Ca^{2+}$ from the IP$_3$-sensitive intracellular store following the initial interaction with membrane component(s) from extracellular side. This signaling pathway of ginsenosides may be one of the action mechanisms for the pharmacological effects of ginseng.ts of ginseng.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.223-235
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• 1993

Background: Superoxide anion which was produced by macrophage and neutrophil has a defensive role to kill invasive microorganisms and also an injurious role to produce self lung damage. Production of oxygen free radicals including superoxide is a main mechanism of acute lung injury caused by bacterial endotoxin. Endotoxin is known to activate alveolar macrophage to produce increased oxygen free radicals after the stimulation with various biological materials (priming effect). Calcium is a very important intracellular messenger in that cellular process of superoxide production. Method: This experiment was performed to elucidate the effects of endotoxin and calcium on superoxide production by phorbol myristate acetate-stimulated alveolar macrophage and the effect of verapamil on priming effect of endotoxin. Results: 1) Preincubation of macrophages with endotoxin (E. coli 055-B5) primed the cells to respond with increased superoxide production after the stimulation with PMA. Priming with endotoxin ($10^{-1}$ug/ml) produced a maximal enhancement of superoxide production (43%). 2) Verapamil could inhibit the superoxide production by PMA stimulated macrophage regardless of the presence of extracellular calcium. This means that the inhibitory effect of verapamil is caused by a mechanism independent of blocking calcium influx. 3) Verapamil could inhibit the priming effect of endotoxin on alveolar macrophage (from 30% increment to 13% increment) and could inhibit the superoxide production by PMA-stimulated macrophage preincubated with endotoxin. Conclusion: We concluded that verapamil could inhibit the superoxide production by PMA-stimulated rat alveolar macrophage and also inhibit the priming effect of endotoxin on alveolar macrophage. These inhibitory effects of verapamil could be one of the mechanisms of verapamil effects on endotoxin induced lung injury.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.72-81
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• 2001

Dendroaspis natriuretic peptide (DNP), recently isolated from the venom of the green Mamba snake Dendroaspis angusticeps, is a 38-amino acid peptide containing a 17-amino acid disulfide ring structure similar to that of the natriuretic peptide family. The natriuretic peptide family was known to induce histamine release from human and rat mast cells, but there are no published data concerning the effects of DNP on histamine release from mast cells. The purpose of this study is to investigate whether DNP induces the histamine release from rat peritoneal mast cells (RMPCs) and to determine the mechanism of DNP-induced histamine release from RPMCs. After treatment of the various doses of DNP in RPMCs, the mast cell degranulation was observed with inverted microscopy and the histamine release was measured by radio-enzymatic assay. Calcium uptake and intracellular cyclic GMP level were measured by radioimmunoassays. DNP induced the mast cell degranulation. DNP released the histamine and increased the calcium uptake and the level of intracellular cyclic GMP of RPMCs, in a dose-dependent manner. The results indicate that DNP is capable of inducing histamine release from RPMCs by increasing of calcium uptake and intracellular cyclic GMP level.