• 한국재료학회지
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• 제21권8호
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• pp.468-475
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• 2011

[ $LaMeO_3$ ](Me = Cr, Co) powders were prepared using the polymeric precursor method. The effects of the chelating agent and the polymeric additive on the synthesis of the $LaMeO_3$ perovskite were studied. The samples were synthesized using ethylene glycol (EG) as the solvent, acetyl acetone (AcAc) as the chelating agent, and polyvinylpyrrolidone (PVP) as the polymer additive. The thermal decomposition behavior of the precursor powder was characterized using a thermal analysis (TG-DTA). The crystallization and particle sizes of the $LaMeO_3$ powders were investigated via powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and particle size analyzer, respectively. The as-prepared precursor primarily has $LaMeO_3$ at the optimum condition, i.e. for a molar ratio of both metal-source (a : a) : EG (80a : 80a) : AcAc (8a) inclusive of 1 wt% PVP. When the as-prepared precursor was calcined at $700^{\circ}C$, only a single phase was observed to correspond with the orthorhombic structure of $LaCrO_3$ and the rhombohedral structure of $LaCoO_3$. A solid-electrolyte impedance-metric sensor device composed of $Li_{1.5}Al_{0.5}Ti_{1.5}(PO_4)_3$ as a transducer and $LaMeO_3$ as a receptor has been systematically investigated for the detection of NOx in the range of 20 to 250 ppm at $400^{\circ}C$. The sensor responses were able to divide the component between resistance and capacitance. The impedance-metric sensor for the NO showed higher sensitivity compared with $NO_2$. The responses of the impedance-metric sensor device showed dependence on each value of the NOx concentration.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2005년도 추계학술대회
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• pp.49-66
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• 2005

Panax ginseng has been useful for the treatment of diverse disease in oriental countries for thousands of years. In addition, a folk medicine prescribed by seven herbal drugs including Panax ginseng has been antinarcotics in the treatment of morphine-dependent patients. Many articles have been reported on these works. Therefore, we review the protective effects of Panax ginseng on the neurotoxicity induced by abuse drugs. Ginseng total saponins (GTS) extracted and isolated by Panax ginseng antagonized Morphine-induced analgesia, and inhibited the development of analgesic tolerance to and physical dependence on morphine. GTS inhibited morphine-6 dehydrogenase, which catalyzes production of mophinone from morphine, and increased hepatic glutathione level responsible to toxicity. Therefore, we hypothesized that these dual actions of ginseng can be associated with the detoxication of morphine. In addition, the inhibitory or facilitated effects of GTS on electrically evoked contraction in guinea pig ileum ($\mu$-receptors) and mouse vas deferens($\delta$-receptors) were not mediated through opioid receptors, suggesting non-opioid mechanisms. On the hand, antagonism of U-50,488H ($\kappa$-agonist)-induced antinociception is mediated by serotonergic mechanisms. GTS also inhibited hyperactivity, reverse tolerance (sensitization) and conditioned place preference-induced by psychostimulants such as methamphetamine, cocaine and morphine. On the other hand, GTS reduced the dopamine levels induced by methamphetamine. Moreover, GTS blocked the development of dopamine receptor activation, showing antidopaminergic effect. We suggest that GTS Prevent the methamphetamine-induced striatal dopaminergic neurotoxicity. In addition, Ginsenoside also attenuates morphine-induced cAMP signaling pathway. These results suggested that GTS might be useful for the therapy of the adverse actions of drugs with abuse liability.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.443-454
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• 1998

The present study was attempted to investigate the effect of vasoactive intestinal polypeptide (VIP) on secretion of catecholamines (CA) and to establish whether there is the existence of a noncholinergic mechanism in adrenomedullary CA secretion from the isolated perfused rat adrenal gland. The perfusion into an adrenal vein of VIP $(3{\times}10^{-6}\;M)$ for 5 min or the injection of acetylcholine (ACh, $5.32{\times}10^{-3}\;M$) resulted in great increases in CA secretion. Tachyphylaxis to releasing effect of CA evoked by VIP was not observed by the repeated perfusion. The net increase in adrenal CA secretion evoked by VIP still remained unaffected in the presence of atropine or chlorisondamine. However, the CA release in response to ACh was greatly inhibited by the pretreatment with atropine or chlorisondamine. The releasing effects of CA evoked by either VIP or ACh were depressed by pretreatment with nicardipine, TMB-8, and the perfusion of $Ca^{2+}$-free medium. Moreover, VIP- as well as ACh-evoked CA secretory responses were markedly inhibited under the presence of $(Lys^1,\;Pro^{2.5},\;Arg^{3.4},\;Tyr^6)-VIP$ or naloxone. CA secretory responses induced by ACh and high $K^+\;(5.6{\times}10^{-2}\;M)$ were potentiated by infusion of VIP $(3{\times}10^{-6}M\;for\;5\;min)$. Taken together, these experimental results indicate that VIP causes CA release in a fashion of calcium ion -dependence, suggesting strongly that there exists a noncholinergic mechanism that may be involved in the regulation of adrenomedullary CA secretion through VIP receptors in the rat adrenal gland, and that VIP may be the noncholinergic excitatory secretagogue present in the chromaffin cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.391-394
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• 2002

There has recently been much interest and research in developing digital x-ray systems based on using amorphous selenium(a-Se) photoconductors as the image receptor. The amorphous selenium layer that is currently being studied for use as an x-ray photoconductor is not pure a-Se but rather amorphous selenium alloyed with arsenic. We fabricated samples using the selenium and arsenic alloy with various concentrations of the arsenic. In this work, x-ray photoconductor using amorphous selenium alloyed with arsenic were fabricated with different concentrations of the arsenic (0.1 wt.%, 0.3wt.%, 0.5wt.%, 1wt.%, 1.5wt.%, 3wt.%, 5wt.%). The seven kind of samples was fabricated with a-Se alloyed with arsenic through vacuum thermal evaporation. We also investigate the arsenic concentration dependence on the device performance in radiation detector. The electric characteristics of radiation detector devices with changing additive ratio of the arsenic is performed by measuring the x-ray induced photocurrent and integrating it over time to find the total charge. The thickness of a-Se is $100{\mu}m$. Bias voltages $3V/{\mu}m$, $6V/{\mu}m$， $9V/{\mu}m$ are applied at the samples. As results, the net charge of a-Se 0.3% As sample is $526.0pC/mR/cm^2$ at $9V/{\mu}m$ bias. The net charge is decreased as with the increasing additive ratio of arsenic.

• Molecules and Cells
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• 제43권6호
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• pp.572-580
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• 2020

Transient receptor potential ankyrin 1 from rattlesnakes (rsTRPA1) and boas (bTRPA1) was previously proposed to underlie thermo-sensitive infrared sensing based on transcript enrichment in infrared-sensing neurons and hyper-thermosensitivity expressed in Xenopus oocytes. It is unknown how these TRPA1s show thermosensitivities that overwhelm other thermoreceptors, and why rsTRPA1 is more thermosensitive than bTRPA1. Here, we show that snake TRPA1s differentially require Ca²⁺ for hyper-thermosensitivity and that predisposition to cytosolic Ca²⁺ potentiation correlates with superior thermosensitivity. Extracellularly applied Ca²⁺ upshifted the temperature coefficients (Q10s) of both TRPA1s, for which rsTRPA1, but not bTRPA1, requires cytosolic Ca²⁺. Intracellular Ca²⁺ chelation and substitutive mutations of the conserved cytosolic Ca²⁺-binding domain lowered rsTRPA1 thermosensitivity comparable to that of bTRPA1. Thapsigargin-evoked Ca²⁺ or calmodulin little affected rsTRPA1 activity or thermosensitivity, implying the importance of precise spatiotemporal action of Ca²⁺. Remarkably, a single rattlesnake-mimicking substitution in the conserved but presumably dormant cytosolic Ca²⁺-binding domain of bTRPA1 substantially enhanced thermosensitivity through cytosolic Ca²⁺ like rsTRPA1, indicating the capability of this single site in the determination of both cytosolic Ca²⁺ dependence and thermosensitivity. Collectively, these data suggest that Ca²⁺ is essential for the hyper-thermosensitivity of these TRPA1s, and cytosolic potentiation by permeating Ca²⁺ may contribute to the natural variation of infrared senses between rattlesnakes and boas.

• 약학회지
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• 제30권3호
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• pp.149-156
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• 1986

Many experiments have showed that the sodium and potassium ion transporting system and the Na, $^+K^+$-ATPase activity of membrane fragments are inhibited by digitalis glycosides and that the pump may be associated with the pharmacological receptor for the drugs. The aim of our investigation is to elucidate the ouabain binding sites occupation in heart following infusion of ouabain to intact animals by the $^3H$-ouabain binding assay. Lethal dose and 26 percent of lethal dose of ouabain were infused to intact rabbit through ear vein. Microsomal fraction was fractionated from ouabain treated rabbit heart. $^3H$-ouabain binding to these fraction in vitro was studied by the Schwartz's method. $^3H$-ouabain binding to heart microsomal fraction was also studied following infusion of ginseng ethanol extract and caffeine to rabbits respectively. 1) The infusion of lethal dose ouabain (113$\mu\textrm{g}$/kg) inhibited the specific $^3H$-ouabain binding to rabbit heart microsomal fraction to the level of 60% (p<0.01) of control group and the infusion of 26% of lethal dose of ouabain led to the level of 79% (p<0.01) of the control group. 2) Time course of binding of 0.4$\mu{M}$ $^3H$-ouabain to microsomal fraction from rabbit heart following infusion of lethal and 26% of lethal dose of ouabain showed dose dependence at various incubation time. 3) Compared with control, only slight change of $K_d$ and $B_{max}$ was detected in in vitro $^3H$-ouabain binding after infusion of ginseng ethanol extract (300mg/kg) to rabbit. 4) In caffeine infusion group, $^3H$-ouabain binding yielded nearly the same results as control group.

• Parasites, Hosts and Diseases
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• 제31권4호
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• pp.379-381
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• 1993

우태아혈청의 성분이 Toxoplasma의 숙주세포 침투를 억제하는 현상을 보여 이를 보고하고자 한다. MDCK세포를 숙주로 하여 Toxoplasma의 RH주를 첨가하였을 때, 우태아혈청 농도 1%(v/v) 에서 억제 효과가 나타나기 시작하여 5%일때 침투능을 반감시켰다. 우태아절청의 비동화 여부는 억제 효과에 영향을 미치지 못하였으며, 우태아혈청을 $95^{\circ}C$에서 10분간 처리하여 억제물질의 기능을 파괴시킬 때 억제 효과는 약간 감소되었다. Toxoprasma를 먼저 우태아혈청으로 처리한 후 숙주 세포에 첨가하였을 때 침투능에는 효과를 미치지 못하였으나, Tomplasma를 숙주세포와 배양하면서 우태아혈청을 첨가하였을 때에는 시간의 경과에 따라 침투능을 억제시켰다. 이상의 결과로 우태아혈청에 Toxoplasma의 숙주세포 침투를 억제하는 성분이 존재하는 것을 확인하였으며, 억제 방법이 침투하는 순간에 일어나며, 억제물질의 기능을 통해서라기 보다는 구조를 통해서 이루어진다고 추정할 수 있었다.

• BMB Reports
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• 제54권2호
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• pp.136-141
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• 2021

Thyroid eye disease (TED) is a complex autoimmune disease with a spectrum of signs. we previously reported that trisialoganglioside (GT)1b is significantly overexpressed in the orbital tissue of TED patients, and that exogenous GT1b strongly induced HA synthesis in orbital fibroblasts. However, the signaling pathway in GT1b-induced hyaluronic acid synthase (HAS) expression in orbital fibroblasts from TED patients have rarely been investigated. Here, we demonstrated that GT1b induced phosphorylation of Akt/mTOR in a dose-dependent manner in orbital fibroblasts from TED patients. Both co-treatment with a specific inhibitor for PI3K and siRNA knockdown of TLR2 attenuated GT1b-induced Akt phosphorylation. GT1b significantly induced HAS2 expression at both the transcriptional and translational level, which was suppressed by specific inhibitors of PI3K or Akt/mTOR, and by siRNA knockdown of TLR2. In conclusion, GT1b induced HAS2 in orbital fibroblasts from TED patients via activation of the PI3K-related signaling pathway, dependent on TLR2.

• 생명과학회지
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• 제17권11호
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• pp.1576-1581
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• 2007

알코올 의존의 음주 행동에 VTA에서 NA로 뻗어 있는 도파민 대뇌 보상 경로가 중요하다. 이러한 경로의 토파민 활성도가 $5-HT_3$계 신경에 의하여 조정되고 있으며, $5-HT_3$ 수용체 길항제인 ondansetron (OND)이 알코올리즘 환자에서 음주량을 감소시키고 금주률을 높인다는 보고가 있다. 이에 생쥐의 섭취량에 대하여 $5-HT_3$ 수용체 길항제인 ondansetron의 투여 효과와, 이러한 ondansetron 및 비 특이적 아편계 수용체 길항제인 naltrexone (NTX)과의 병합 투여 효과를 검증하는데 목적이 있다. 알코올 의존화 된 C57BL/6형 수컷 생쥐를 4군으로 나눈 뒤, 10일간 각 군에 vehicle, OND 0.01 mg/kg 단독, NTX 1.0 mg/kg 단독, 및 OND 0.01 mg/kg과 NTX 1 mg/kg 병합 투여하면서 2시간 알코올의 섭취량, 22시간 물 섭취량, 24시간 사료 섭취량 및 체중을 조사하였다. 본 연구의 결과로 2시간 알코올 섭취량의 10일간 변화에 대해 vehicle 투여 군과 나머지 3군의 약물 투여군과 repeated measure ANOVA를 이용하여 각각 비교하였을 때, vehicle 투여군과 NTX 단독 투여군간에 유의한 교차가 관찰되었으나 (p=0.042), OND 단독 투여군과 NTX과 OND 병합 투여군은 vehicle 투여군과 유의한 차이가 없었다. 일별 2시간 알코올 섭취량에 대하여 NTX 투여군과 vehicle 투여군의 군간 비교시 vehicle 투여군에 비하여 NTX 투여군에서 약물 투여 4일부터 10일까지 유의하게 감소하였다(4일 p=0.010; 6일 p=0.050; 8일 p=0.017; 10일 p=0.005). 그리고 NTX과 OND 병합 투여군과 vehicle 투여군의 양군을 비교하였을 때에는 2시간 알코올 섭취량이 4일과 10일에만 유의하게 감소하였다(4일 p=0.049; 10일 p=0.022). 그러나 22시간 물 섭취량, 24시간 사료 섭취량 및 체중의 10일간 변화에 대해 vehicle 투여군과 나머지 3 군의 약물 투여군과의 repeated measure ANOVA를 이용하여 각각 비교하였을 때, 모두 유의한 교차효과가 없었다. 이상의 결과는 생쥐의 섭취량에 대하여 OND의 투여 효과는 없었으며, OND과 NTX의 병합 투여시에는 NTX의 알코올의 섭취량 억제 효과가 감소되었다. 따라서 앞으로 $5-HT_3$ 신경계와 도파민 및 아편 신경계와의 상관관계에 대한 연구가 필요할 것으로 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.297-305
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• 1998

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.