• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.213-218
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• 1997

Total lipid were extracted from the eggs, livers, intestines, muscles, and testis of Fugu xanthopterus. The fatty acid composition of total lipid was analyzed by gas liquid chromatography. Proximate percentage of total lipid from the samples was shown to be ; 81.72% in the livers, 14.53% in the intestines, 12.63% in the eggs, 0.85% in the muscles, and 1.74% in the testis. Toxins(tetrodotoxins) were completely removed from the liver of Fugu xanthopterus with 1% acetic acid/methanol solution before total lipid was extracted with CHCI3:methanol solution(2:1, v/v). The toxicity left in the total lipid was checked using mice. The content of DHA in each tissues of Fugu xanthopterus was the most abundant in muscle(32.4%), followed by liver(23.0%), intestine(26.7%) and testis(15.4%). The level of total polyenoic acids comprising DHA was more abundant in muscle(57.4%) than in the liver(50.9%).

• International Journal of Oral Biology
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• v.33 no.4
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• pp.217-221
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• 2008

Bicuculline is one of the most commonly used $GABA_A$ receptor antagonists in electrophysiological research. Because of its poor water solubility, bicuculline quaternary ammonium salts such as bicuculline methiodide (BMI) and bicuculline methbromide are preferred. However, a number of studies have shown that BMI has non-$GABA_A$ receptor-mediated effects. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is implicated in the processing of nociceptive signaling. In this study, we investigated whether BMI has non-GABA receptor-mediated activity in Vc SG neurons using a whole cell patch clamp technique. SG neurons were depolarized by application of BMI ($20{\mu}M$) using a high $Cl^-$ pipette solution. GABA ($30-100{\mu}M$) also induced membrane depolarization of SG neuron. Although BMI is known to be a $GABA_A$ receptor antagonist, GABA-induced membrane depolarization was enhanced by co-application with BMI. However, free base bicuculline (fBIC) and picrotoxin (PTX), a $GABA_A$ and $GABA_C$ receptor antagonist, blocked the GABA-induced response. Furthermore, BMI-induced membrane depolarization persisted in the presence of PTX or an antagonist cocktail consisting of tetrodotoxin ($Na^+$ channel blocker), AP-5 (NMDA receptor antagonist), CNQX (non-NMDA receptor antagonist), and strychnine (glycine receptor antagonist). Thus BMI induces membrane depolarization by directly acting on postsynaptic Vc SG neurons in a manner which is independent of $GABA_A$ receptors. These results suggest that other unknown mechanisms may be involved in BMI-induced membrane depolarization.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.6
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• pp.337-342
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• 2008

Human bone marrow mesenchymal stem cells (hBM-MSCs) represent a potentially valuable cell type for clinical therapeutic applications. The present study was designed to evaluate the effect of long-term culturing (up to $10^{th}$ passages) of hBM-MSCs from eight individual amyotrophic lateral sclerosis (ALS) patients, focusing on functional ion channels. All hBM-MSCs contain several MSCs markers with no significant differences, whereas the distribution of functional ion channels was shown to be different between cells. Four types of $K^+$ currents, including noise-like $Ca^{+2}$-activated $K^+$ current ($IK_{Ca}$), a transient outward $K^+$ current ($I_{to}$), a delayed rectifier $K^+$ current ($IK_{DR}$), and an inward-rectifier $K^+$ current ($K_{ir}$) were heterogeneously present in these cells, and a TTX-sensitive $Na^+$ current ($I_{Na,TTX}$) was also recorded. In the RT-PCR analysis, Kv1.1,, heag1, Kv4.2, Kir2.1, MaxiK, and hNE-Na were detected. In particular, ($I_{Na,TTX}$) showed a significant passage-dependent increase. This is the first report showing that functional ion channel profiling depend on the cellular passage of hBM-MSCs.

• Biomolecules & Therapeutics
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• v.28 no.4
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• pp.328-336
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• 2020

Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α₁ adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca²⁺ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE₅ inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE₅ were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE₅.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.599-605
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• 1996

This study was designed to examine the mechanism of penile erection in adult bull by analyzing the responses of bovine proximal retractor penile muscle strips(BRP) to electtical field stimulation(EFS), exogenous nitric oxide(NO), NO synthesis precursor(L-arginine), NO synthase inhibitors(L-NAME, L-NMMA), guanylate cyclase inhibitor(methylene blue) and nonspecific potassium channel blocker(tetraethylammonium, TEA) treatments. Isometric tension of BRP was measured using physiograph. Results were summarized as follows: 1. EFS of nonadrenergic noncholinrgic(NANC) nerve in BRP produced frequency-dependent inhibitory responses to the contraction induced by co-treatment of epinephrine, guanethidine and atropine. The inhibitory responses to EFS were blocked by tetrodotoxin(TTX, $1{\mu}M$). 2. Treatment of L-NAME ($10,\;20{\mu}M$) inhibited the relaxation to EFS whereas L-NMMA ($100{\mu}M$) had no effect. 3. Treatment of NO($20,\;40{\mu}M$; as an acidified solution of $NaNO_2$) induced concentration-dependent relaxation whereas preincubation of TTX($1{\mu}M$) and L-NAME($20{\mu}M$) had no effect on the relaxation response. 4. L-arginine treatment(10mM) blocked the inhibitory effect of L-NAME($20{\mu}M$). 5. Pretreatment of methylene blue($40{\mu}M$) reduced the NANC-induced relaxation of BRP. 6. Tetraethylammonium(TEA, 80mM) reduced NANC relaxation. These results suggest that NO may act as a NANC neurotransmitter in BRP and the effects might be mediated by cGMP and potassium channel.

• The Korean Journal of Pharmacology
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• v.32 no.2
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• pp.139-150
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• 1996

The effects of adenosine analogues on the electrically-evoked norepinephrine(NE) release and the influence of ischemia on the effects were studied in the rat hippocampus. Slices from the rat hippocampus were equilibrated with $0.1{\mu}M$ $[^3H]-norepinephrine$ and the release of the labelled product, $[^3H]-NE$, was evoked by electrical stimulation(3 Hz, 2 ms, 5 $VCm^{-1}$ and rectangular pulses for 90 sec), and the influence of various agents on the evoked tritium-outflow was investigated. Ischemia(15min with 95% $N_2$ +5% $CO_2$) increased both the basal and evoked NE release. These increases were abolished by addition of glucose into the superfused medium, and they were significantly inhibited either by $0.3\;{\mu}M$ tetrodotoxin pretreatment or by removing $Ca^{++}$ in the medium. MK-801$(1{sim}10\;{\mu}M)$, a specific NMDA receptor antagonist, and glibenclamide $(1\;{\mu}M)$, a $K^+-channel$ inhibitor, neither alter the evoked NE release nor affected the Ischemia-Induced increases in NE release. However, polymyxin B(0.03 mg), a specific protein kinase C inhibitor, inhibited the effect of ischemia on the evoked NE release. Adenosine and $N^6-cyclopentyladenosine$ decreased the NE release in a dose-dependent manner in ischemic condition, though the magnitude of inhibition was far less than those in normal (normoxic) condition. Also the treatment with $5{\mu}M$ DPCPX, a potent $A_1-adenosine$ receptor antagonist did not affect the ischemia-effect. These results suggest that the evoked-NE release is potentiated by ischemia, and this process being most probably mediated by protein kinase C, and that the decrease of NE release mediated through $A_1-adenosine$ receptor is significantly inhibited in ischemic state.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.5
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• pp.393-400
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• 2009

NO released by myenteric neurons controls the off contraction induced by electrical field stimulation (EFS) in distal esophageal smooth muscle, but in the presence of nitric oxide synthase (NOS) inhibitor, L-NAME, contraction by EFS occurs at the same time. The authors investigated the intracellular signaling pathways related with G protein and ionic channel EFS-induced contraction using cat esophageal muscles. EFS-induced contractions were significantly suppressed by tetrodotoxin ($1\;{\mu}M$) and atropine ($1\;{\mu}M$). Furthermore, nimodipine inhibited both on and off contractions by EFS in a concentration dependent meaner. The characteristics of 'on' and 'off contraction and the effects of G-proteins, phospholipase, and $K^+$ channel on EFS-induced contraction in smooth muscle were also investigated. Pertussis toxin (PTX, a $G_i$ inactivator) attenuated both EFS-induced contractions. Cholera toxin (CTX, $G_s$ inactivator) also decreased the amplitudes of EFS-induced off and on contractions. However, phospholipase inhibitors did not affect these contractions. Pinacidil (a $K^+$ channel opener) decreased these contractions, and tetraethylammonium (TEA, ${K^+}_{Ca}$ channel blocker) increased them. These results suggest that EFS-induced on and off contractions can be mediated by the activations Gi or Gs proteins, and that L-type $Ca^{2+}$ channel may be activated by G-protein ${\alpha}$ subunits. Furthermore, ${K^+}_{Ca^-}$ channel involve in the depolarization of esophageal smooth muscle. Further studies are required to characterize the physiological regulation of $Ca^{2+}$ channel and to investigate the effects of other $K^+$ channels on EFS-induced on and off contractions.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.47-54
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• 2012

Korean red ginseng (KRG) has been used worldwide as a traditional medicine for the treatment of various reproductive diseases. Gonadotropin releasing hormone (GnRH) neurons are the fundamental regulators of pulsatile release of gonadotropin required for fertility. In this study, an extract of KRG (KRGE) was applied to GnRH neurons to identify the receptors activated by KRGE. The brain slice patch clamp technique in whole cell and perforated patch was used to clarify the effect of KRGE on the membrane currents and membrane potentials of GnRH neurons. Application of KRGE (3 ${\mu}g$/${\mu}L$) under whole cell patch induced remarkable inward currents (56.17${\pm}$7.45 pA, n=25) and depolarization (12.91${\pm}$3.80 mV, n=4) in GnRH neurons under high $Cl^-$ pipette solution condition. These inward currents were not only reproducible, but also concentration dependent. In addition, inward currents and depolarization induced by KRGE persisted in the presence of the voltage gated $Na^+$ channel blocker tetrodotoxin (TTX), suggesting that the responses by KRGE were postsynaptic events. Application of KRGE under the gramicidin perforated patch induced depolarization in the presence of TTX suggesting its physiological significance on GnRH response. Further, the KRGE-induced inward currents were partially blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; non-NMDA glutamate receptor antagonist, 10 ${\mu}M$) or picrotoxin (PIC; $GABA_A$ receptor antagonist, 50 ${\mu}M$), and almost blocked by PIC and CNQX mixture. Taken together, these results suggest that KRGE contains ingredients with possible GABA and non-NMDA glutamate receptor mimetic activity, and may play an important role in the endocrine function of reproductive physiology, via activation of $GABA_A$ and non-NMDA glutamate receptors in GnRH neurons.

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.400-404
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• 2006

This study examined the effect of Gamma-Amino butyric acid (GABA) and selective GABA receptor related drugs on the electrically stimulated relaxation in the lower esophageal sphincter muscle (LES) of a cat. Tetrodotoxin $(10^{-6}\;M)$ suppressed the electrically stimulated (0.5-5 Hz) relaxation of the LES. However, guanethidine $(10^{-6}\;M)$ and atropine $(10^{-6}\;M)$ had no effect indicating that the relaxations were neurally mediated via the nonadrenergic and noncholinergic (NANC) pathways. NG-nitro-L-arginine methyl ester ($10^{-4}M$, L-NAME) also inhibited the relaxant response but did not completely abolish the electrically stimulated relaxation with 60% inhibition, which suggests the involvement of nitric oxide as an inhibitory transmitter. This study examined the role of GABA, an inhibitory neurotransmitter, on neurally mediated LES relaxation. GABA ($10^{-3}-10^{-5}M$, non selective receptor agonist), muscimol ($10^{-3}-10^{-5}M$, GABA-A agonist), and baclofen ($10^{-3}-10^{-5}M$, GABA-B agonist) had no significant effect on the electrically stimulated relaxation. Moreover, bicuculline ($10^{-5}M$, GABA-A antagonist) and phaclofen ($10^{-5}M$, GABA-B antagonist) had no inhibitory effect on the electrically stimulated relaxation. This suggests that GABA and the GABA receptor are not involved in the electrically stimulated NANC relaxation in the cat LES.

• Journal of Ginseng Research
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• v.35 no.2
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• pp.219-225
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• 2011

Korean red ginseng (KRG) is a valuable and important traditional medicine in East Asian countries and is currently used extensively for botanical products in the world. KRG has both stimulatory and inhibitory effects on the central nervous system (CNS) suggesting its complicated action mechanisms. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) are involved in orofacial nociceptive processing. Some studies reported that KRG has antinociceptive effects, but there are few reports of the functional studies of KRG on the SG neurons of the Vc. In this study, a whole cell patch clamp study was performed to examine the action mechanism of a KRG extract on the SG neurons of the Vc from juvenile mice. KRG induced short-lived and repeatable inward currents on all the SG neurons tested in the high chloride pipette solution. The KRG-induced inward currents were concentration dependent and were maintained in the presence of tetrodotoxin, a voltage gated $Na^+$ channel blocker. The KRG-induced inward currents were suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist and/or picrotoxin, a gamma-aminobutyric acid $(GABA)_A$ receptor antagonist. However, the inward currents were not suppressed by d,l-2-amino-5-phosphonopentanoic acid, an NMDA receptor antagonist. These results show that KRG has excitatory effects on the SG neurons of the Vc via the activation of non-NMDA glutamate receptor as well as an inhibitory effect by activation of the $GABA_A$ receptor, indicating the KRG has both stimulatory and inhibitory effects on the CNS. In addition, KRG may be a potential target for modulating orofacial pain processing.