• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.215-231
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• 2002

삼차신경절의 뉴론이 구강악안면영역에서의 촉각, 압각, 온도각 및 통각 등 다양한 감각을 중추신경계로 전달하는 역할을 하는 것은 주지의 사실이다. 이러한 신경전달에 있어서 이온통로는 감각정보를 전달하는데 핵심적인 역할을 수행한다. 이 중 소디움 통로는 활동전위의 발생에 중요하며, 칼슘 통로는 시냅스 전도에 있어서 필수적인 역할을 수행하고, 포타슘 통로는 안정막전압의 유지 및 재분극에 관여한다. 최근에 여러 가지의 이온통로들의 뇌조직내의 분포에 관한 연구가 시작되고 있는데 삼차신경의 일차구심뉴론이 종지하는 삼차신경핵 즉 삼차신경 척수감각핵, 삼차신경 주감각핵, 삼차신경 중뇌핵 및 삼차신경 운동핵에 존재하는 이온통로에 관한 연구는 매우 희소하여 본 연구에서는 횐쥐의 삼차신경 핵에 존재하는 소디움, 칼슘 및 포타슘 이온통로들을 면역조직화학적 방법으로 조사하여 다음과 같은 결과를 얻었다. (1) 소디움 통로는 삼차신경 척수감각핵, 삼차신경 주감각핵 및 삼차신경 운동핵 모두에서 강하게 염색되었다. (2) 칼슘 통로는 삼차신경 척수감각핵에서는 N-type 통로가 중등도로 염색되었으며 , P/Q-type 통로는 약하게 염색되었으나 R-type 통로는 거의 염색되지 않았다. 삼차신경 주감각핵에서는 P/Q-type 통로가 매우 약하게 염색되었다. (3) 포타슘 통로는 삼차신경 척수감각핵과 삼차신경 주감각핵에서 inwardly rectifying 포타슘 통로(Kir 2.1)가 중등도로 염색되었고, voltage-gated 포타슘 통로(Kv 4.2)가 약하게 염색되었으며, BKCa는 그 염색 정도가 매우 약하게 나타났다. 이상의 결과를 종합해 볼 때 삼차신경 감각핵에는 소디움 통로의 분포가 가장 많았으며, 칼슘통로에서는 N-type이, 포타슘 통로 중에는 inwardly rectifying 통로(Kir 2.1)가 가장 많이 분포함을 관찰할 수 있었다.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.35-43
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• 2006

Ions play important roles in various cellular processes including fertilization and differentiation. However, it is little known whether how ions are regulated during early embryonic development in mammalian animals. In this study, we examined changes in $Ca^{2+}\;and\;K^+$ concentrations in embryos and oviduct during mouse early embryonic development using patch clamp technique and confocal laser scanning microscopy. The intracellular calcium concentration in each stage embryos did not markedly change. At 56h afier hCG injection when 8-cell embryos could be Isolated from oviduct, $K^+$ concentration in oviduct increased by 26% compared with that at 14h after injection of hCG During early embryonic development, membrane potential was depolarized (from -38 mV to -16 mV), and $Ca^{2+}$ currents decreased, indicating that some $K^+$ channel might control membrane potential in oocytes. To record the changes in membrane potential induced by influx of $Ca^{2+}$ in mouse oocytes, we applied 5 mM $Ca^{2+}$ to the bath solution. The membrane potential transiently hyperpolarized and then recovered. In order to classify $K^+$ channels that cause hyperpolarization, we first applied TEA and apamin, general $K^+$ channel blockers, to the bath solution. Interestingly, the hyperpolarization of membrane potential still appeared in oocytes pretreated with TEA and apamin. This result suggest that the $K^+$ channel that induces hyperpolarization could belong to another $K^+$ channel such as two-pore domain $K^+(K_{2P})$channel that a.e insensitive to TEA and apamin. From these results, we suggest that the changes in $Ca^{2+}\;and\;K^+$ concentrations play a critical role in cell proliferation, differentiation and reproduction as well as early embryonic development, and $K_{2P}$ channels could be involved in regulation of membrane potential in ovulated oocytes.

• Restorative Dentistry and Endodontics
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• v.27 no.5
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• pp.451-462
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• 2002

삼차신경은 구강악안면영역의 운동 및 감각을 담당하고 있으므로 치과임상에서 매우 중요하다. 삼차신경근 중 삼차신경절에 세포체를 갖는 뉴론은 주로 체성 감각을 전달하는 1차 구심신경으로 악안면영역의 촉각, 압각, 진동감각 온도각 및 통각을 담당한다. 이러한 감각의 전달은 기본적으로 신경세포의 이온통로의 활동에 의존하는데 삼차신경절 세포에 여러 종류의 이온통로가 존재하는 것으로 알려져 있다. 본 연구에서는 항체 염색법을 이용하여 이온통로가 존재를 확인 하고자 한다. 횐쥐의 삼차신경절로부터 통법에 따라 뉴론을 단일 세포로 분리하고 immunocytochemistry 방법으로 세포를 염색하여 관찰한 바 다음과 같은 결과를 얻었다. 본 실험에서 이온전류의 측정 등으로 관찰된 여러 종류의 이온통로들을 면역 염색법으로 확인하였다. 횐쥐의 삼차신경절 뉴론에서 확인된 이온통로는 소디움통로와 N, P 및 Q-type의 칼슘통로 그리고 BK$_{Ca}$, Kv 4.2 및 Kir 2.1 등의 포타슘통로이었으며 이온통로의 종류에 따라 분포에 차이를 나타내었다.

• Journal of Embryo Transfer
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• v.22 no.3
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• pp.149-154
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• 2007

Endometrial cells play important roles in implantation and during pregnancy. This study was carried out to identify whether two-pore domain $K^+\;(K_{2P})$ channels are expressed in endometrial cells of Korean cattle. $K_{2P}$ channels set the resting membrane potential of many kinds of neuronal cells in the central and peripheral nervous systems. RT-PCR data showed that TASK-1, TASK-3, TREK-1, TREK-2, and TRAAK were expressed in bovine endometrial cells, and the mRNA expression levels were similar between endometrial cells with or without endometritis. The protein expression was confirmed by using commercially available polyclonal antibodies (TASK-3, TREK-1, TREK-2, and TRAAK). TASK-3 and TREK-1 were expressed in all area of endometrial cells including nuclei, while TREK-2 and TRAAK were expressed in all area of cells except nuclei. These results demonstrate for the first time the presence of $K_{2P}$ channel in endometrial cells of Korean cattle.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.71-81
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• 1988

Glutamate and aspartate may evoke an increase in membrane permeability to monovalent cations and $Ca^{++}$. However, it is uncertain whether $Ca^{++}$ influx is mediated by voltage dependent $Ca^{++}$ channels or by excitatory amino acid activated channels. In addition, the influences of excitatory amino acids on $Ca^{++}$ uptake by neuronal tissues as well as the responses of their actions to extracellular $Mg^{++}$ concentration are different. $K^{+}$ induced $Ca^{++}$ uptake by synaptosomes was dependent on extracellular $Mg^{++}$ up to 5 mM and at concentration of 10 mM, $Ca^{++}$ influx was rather reduced. In $Na^{+}$ rich media, glutamate-and aspartate-induced $Ca^{++}$ uptake was increased by $Mg^{++}$ in a dose independent manner. However, the response for NMDA was inhibited by $Mg^{++}$ at concentrations above 2 mM. $K^+$-and glutamate-induced $Ca^{++}$ influx s were inhibited by 2,4-dinitrophenol, chlorprom-azine and verapamil but not by tetraethylammonium chloride. Tetrodotoxin effectively inhibited the action of glutamate but did not affect that of $K^+$. The response for MNDA was inhibited by 2, 4-dinitrophenol and tetrodotoxin, slightly inhibited by verapamil, and not affected by tetraethylammonium chloride. In $Na^{++}$ rich medium, depolarizing action of glutamate, aspartate and MNDA on synaptosomes was not demonstrated, whereas these agents stimulated $Ca^{++}$ uptake and caused $Ca^{++}$ influx induced depolarization at mitochondria. On the other hand, the activities of synaptosomal ATPases were not affected by excitatory amino acids at 5 mM. The results suggest that glutamate or NMDA induced $Ca^{++}$ influx at synaptosomes exhibits different responses for extracellular $Mg^{++}$ Ex citatory amino acids induced $Ca^{++}$ influx at synaptosomes may be associated with increased permeability of membrane for $Na^{++}$ and $Ca^{++}$ except $K^{++}$ and membrane depolarization due to increased ionic permeability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1964-1971
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• 2015

Human bone marrow or human umbilical cord vein derived-mesenchymal stem cells (hBM-MSCs or hUC-MSCs) have known as a potentially useful cell type for clinical therapeutic applications. We investigated two-pore domain potassium (K2P) channels in these cells. K2P channels play a major role in setting the resting membrane potential in many cell types. Among them, TREK1 is targets of hydrogen, hypoxia, polyunsaturated fatty acids, antidepressant, and neurotransmitters. We investigated whether hBM-MSCs and hUC-MSCs express functional TREK1 channel using RT-PCR analysis and patch clamp technique. Potassium channel with a single channel conductance of 100 pS was found in hUC-MSCs and BM-MSCs and the channel was activated by membrane stretch (-5 mmHg ~ -15 mmHg), arachidonic acid ($10{\mu}M$) and intracellular acidosis (pH 6.0). These electrophysiological properties were similar to those of TREK1. Our results suggest that TREK1 is functionally present in hBM-MSCs and hUC-MSCs, where they contribute to its resting membrane potential.

• The Korean Journal of Pharmacology
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• v.27 no.1
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• pp.45-52
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• 1991

The inhibitory effects of GS354 and GS389 on cytosolic $Ca^{2+}$ level ($[Ca^{2+}]_{1}$; measured with fura-2 fluorescence) and muscle tension in vascular smooth muscle of rat thoracic aorta were investigated. Both GS354 and GS389 inhibited the contractions induced by high $K^+$ or by norepinephrine. The vasodilator effect of GS354 was accompanied by a decrease in $[Ca^{2+}]_{1}$. The inhibitory effect on high $K^+-stimulated$ $[Ca^{2+}]_{1}$ was antagonized by a $Ca^{2+}$ channel activator, Bay K8644. However, the inhibitory effect on muscle tension was not antagonized by Bay K8644. These results suggest that GS354 inhibits $Ca^{2+}$ channels to decrease $[Ca^{2+}]_{1}$ and also decreases $Ca^{2+}$ sensitivity of contractile elements. The inhibitory effects of GS389 was accompanied by the increase in tissue fluorescence. This increment was not due to fura-2 fluorescence but to endogeneous pyridine nucleotides, suggesting that GS389 has an effect to inhibit mitochondrial function. Because of this interference, effects of GS389 on $[Ca^{2+}]_{1}$ was obscured. However, since sequential addition of Bay K8644 in the presence of GS389 further increased the fluorescence but not muscle tension, this compound seems to have the effects to inhibit $Ca^{2+}$ channels and to decrease $Ca^{2+}$ sensitivity of contractile elements.