• The Korean Journal of Physiology
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• v.25 no.2
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• pp.147-158
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• 1991

The effects of noradrenaline on the spontaneous contraction recorded from a strip of mucosa-free antral circular muscle were studied in the guinea-pig stomach, and the changes in slow waves and membrane resistance were analyzed in order to elucidate the mechanism for the excitatory response to noradrenaline. Electrical responses of circular muscle cells were recorded using glass microelectrodes filled with 3 M KCI. Electrotonic potentials were produced to estimate membrane resistance by the partition stimulating method. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The spontaneous contractions were potentiated dose-dependently by the application of noradrenaline. 2) Through the experiments using adrenoceptor-blockers, the strong excitatory effect via $[\alpha}-adrenoceptors$ and the weak inhibitory efffect via ${\beta}-adrenoceptors$ were noted. 3) Noradrenaline produced hyperpolarization of membrane potential, and increases in the amplitude and the maximum rate of rise of slow waves. 4) In the presence of apamin, Ca-dependent K channel blocker, the characteristic hyperpolarization was not developed. However, the excitatory effect of noradrenaline on spontaneous contraction remained. 5) Membrane resistance was reduced during the hyperpolarized state by the application of noradrenaline, and the change of membrane resistance and the hyperpolarized state were completely abolished by apamin. From the above results, following conclusions could be made: Excitatory responses to noradrenaline result from the dominant ${\alpha}-excitatory$, and the weak ${\beta}-inhibitory$ action of noradrenaline. Hyperpolarization of membrane potential by noradrenaline is due to the activation of Ca-dependent K channel.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.95-100
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• 1998

The conductance change evoked by step depolarization was studied in primarily cultured rat adrenal chromaffin cells using patch-clamp and capacitance measurement techniques. When we applied a depolarizing pulse to a chromaffin cell, the inward calcium current was followed by an outward current and depolarization-induced exocytosis was accompanied by an increase in conductance trace. The slow inward tail current which has the same time course as the conductance change was observed in current recording. The activation of slow tail current was calcium-dependent. Reversal potentials agreed with Nernst equation assuming relative permeability of $Cs^+\;to\;K^+$ is 0.095. The outward current and tail current were blocked by apamin (200 nM) and d-tubocurarine (2 mM). The conductance change was blocked by apamin and did not affect membrane capacitance recording. We confirmed that conductance change after depolarization comes from the activation of the SK channel and can be blocked by application of the SK channel blockers. Consequently, it is necessary to consider blocking of the SK channel during membrane capacitance recording.

• Journal of Acupuncture Research
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• v.34 no.1
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• pp.31-38
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• 2017

Objectives : The purpose of this study was to analyze the components of the clinically used bee venom (BV) pharmacopuncture. Methods : Two kinds of bee venom pharmacopuncture (BV-I and II), three kinds of separate purification BV (SPBV) pharmacopuncture (SPBV-I, II, and III), and apitoxin were investigated in this study. We performed a component analysis of melittin, apamin, and phospholipase $A_2$ using high-performance liquid chromatography (HPLC). Results :1. BV-I contained approximately 40% more melittin than BV-II did. 2. In the three separate purification BV pharmacopuncture, SPBV-I, SPBV-II, and SPBV-III, phospholipase $A_2$ content decreased remarkably. 3. The melittin content in SPBV-I increased by 5% compared to that in BV-I. 4. The amount of melittin in apitoxin was similar to that in SPBV-I. Conclusion : The compositions of the BV pharmacopuncture and separate purification BV pharmacopuncture changed depending on the collection method and concentration. Therefore, it is necessary to choose the most suitable BV for each specific medical treatment target. Furthermore, research into the composition of BV may be needed for its safe and effective use.

• Analytical Science and Technology
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• v.27 no.6
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• pp.277-283
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• 2014

The effects of concentration, pressure, and molecular sige on removing allergenic substance (phospholipase $A_2$) in bee venom by ultrafiltration were investigated. The membrane pore sizes were selected based on the molecular weight of the main compounds. The conditions of concentration and pressure were selected randomly. As results, we obtained the optimum condition (1 mg/mL, 20 psi, 10,000 dalton) for removing $PLA_2$ at constant concentration of melittin and apamin and confirmed the separation results by HPLC and SDS-PAGE.

• 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.

• Journal of Acupuncture Research
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• v.19 no.2
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• pp.65-77
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• 2002

Objective : This study was undertaken to determine which compound of Bee Venom for herb-acupuncture has cytotoxicity on mouse mast cell line. Methods : We compared crude bee venom and its compounds such as melittin, mast cell degranulating peptide (MCD peptide), apamin with control groups on cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results & Conclusion : 1. Crude bee venom showed significant cytotoxic effect(p<0.01) in 1 hour treatment with $1{\mu}g/m{\ell}$ in comparison with control group in 1 hour treatment with low concentration of $10-4{\mu}g/m{\ell}$, $10-3{\mu}g/m{\ell}$, $10-2{\mu}g/m{\ell}$, $10-1{\mu}g/m{\ell}$ and $1{\mu}g/m{\ell}$, but it showed no significant cytotoxic effect in 6 hours treatment. 2. Melittin group showed no significant cytotoxic effect in comparison with control group in 1 and 6 hours treatment with low concentration of $10-4{\mu}g/m{\ell}$, $10-3{\mu}g/m{\ell}$, $10-2{\mu}g/m{\ell}$, $10-1{\mu}g/m{\ell}$ and $1{\mu}g/m{\ell}$. 3. MCD peptide and Apamin group showed no significant cytotoxic effect in comparison with control group in 1 and 6 hours treatment with low concentration of $10-4{\mu}g/m{\ell}$ $10-3{\mu}g/m{\ell}$, $10-2{\mu}g/m{\ell}$, $10-1{\mu}g/m{\ell}$ and $1{\mu}g/m{\ell}$. 4. Crude bee venom showed significant cytotoxic effect(p<0.01) in 1 and 6 hours treatment in comparison with control group in 1 and 6 hours treatment with high concentration of $10{\mu}g/m{\ell}$, $20{\mu}g/m{\ell}$ and $102{\mu}g/m{\ell}$. 5. Melittin group showed significant cytotoxic effect(p<0.01) in 1 hour treatment in comparison with control group in 1 hour treatment with high concentration of $10{\mu}g/m{\ell}$ but it showed no significant cytotoxic effect in 6 hours treatment. 6. Crude bee venom and its compounds have more cytotoxic effect in 1 hour treatment than in 6 hours treatment. It means cytotoxicity tends to decrease according to the treatment time.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.151.2-152
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• 2003

Bee venom (BV) has been utilized to relieve pain and to treat inflammatory diseases such as rheumatoid arthritis (RA). BV contains a variety of different peptides including melittin, apamin, adolapin and mast cell degranulating (MCD) peptide. In addition, it also contains enzyme (i.e. phospholipase A2), biologically active amines and non-peptide components. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.215-219
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• 2007

Small and large conductance $Ca^{2+}$-activated $K^+(SK_{Ca}\;and\;BK_{Ca})$ channels are implicated in the modulation of neuronal excitability. We investigated how changes in peripheral $K_{Ca}$ channel activity affect mechanical sensitivity as well as the afferent fiber type responsible for $K_{Ca}$ channel-induced mechanical sensitivity. Blockade of $SK_{Ca}$ and $BK_{Ca}$ channels induced a sustained decrease of mechanical threshold which was significantly attenuated by topical application of capsaicin onto afferent fiber and intraplantar injection of 1-ethyl-2-benzimidazolinone. NS1619 selectively attenuated the decrease of mechanical threshold induced by charybdotoxin, but not by apamin. Spontaneous flinching and paw thickness were not significantly different after $K_{Ca}$ channel blockade. These results suggest that mechanical sensitivity can be modulated by $K_{Ca}$ channels on capsaicin-sensitive afferent fibers.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.117-117
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• 2003

Bee Venom (BV) has been treated in inflammatory diseases such as rheumatoid arthritis (RA). Bee venom contains several biologically active non-peptide substances as well as two major known peptides; the hemolytic peptide melittin (50%) and the neurotoxic peptide apamin, and a number of minor peptides.(omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.93.1-93.1
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• 2003

Bee Venom (BV) has been treated in inflammatory diseases such as rheumatoid arthritis (RA). Bee venom contains several biologically active non-peptide substances as well as two major known peptides; the hemolytic peptide melittin (50%) and the neurotoxic peptide apamin, and a number of minor peptides. Previous our study showed that BV blocked LPS and SNP-induced production of NO and PG through inactivation of NF-kB which regulates expression of COX-2 and iNOS. (omitted)