• 한국안광학회지
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• 제1권1호
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• pp.115-118
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• 1996

생쥐 섬유모세포주 L929 세포에 미치는 중금속류와 중금속 착화제의 세포독성 정도를 측정하기 위해 96 well microtiter plate를 이용한 간편한 비색검정 방법, 즉 neutral red(NR)와 tetrazolium MTT 정량을 실시하였다. NR과 MTT정량으로 측정한 결과 세포독성은 카드뮴 > 아연 > 니켈 > 3가크롬의 순서로 나타났다. 또한 두개의 중금속을 동시에 처리한 결과 아연에 의해 카드뮴의 독성이 감소되었으며 니켈과 크롬을 동시에 처리한 결과 니켈의 독성이 감소하였다. 그리고 착화제로 EDTA와 Chitosan을 처리한 결과 세포독성이 현저하게 감소되는 것으로 나타났다.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.169-169
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• 2002

The mobilizable amount of transition metals is a fraction of the total amount of the metal from urban particulate matter. Although the fraction is small, some metals (Fe, Cu) are the major participants in a reaction that generates reactive oxygen species (ROS), which can damage various biomolecules. Damaging effects of the metals can be measured by the single strand breakage (SSB) of X174 RFI DNA or the carbonyl formation of protein. In another study, we have shown that more metals are mobilized by PM2.5 than by PM10 in general. DNA SSB of >20% for PM2.5 and >15% for PM10 was observed in the presence of chelator (EDTA or citrate)/reductant (ascorbate), compared to the control (<3%) only with the chelator. The carbonyl formation by both PMs was very similar in the presence of the chelator, regardless of the kind of proteins. Compared to the control in the absence of chelator/reductant, 3.3 times and 4.9 times more carbonyl formation for PM2.5 and PM10, respectively, was obtained with BSA in the presence of chelator/reductant, showing that PM10 induced 33% more damage than PM2.5. However, 4.8 times and 1.9 times more carbonyl formation for PM2.5 and PM10, respectively, was observed with lysozyme in the presence of chelator/reductant, showing that PM2.5 induced 250% more damage than PM10. Although different proteins showed different sensitivities toward ROS, all these results indicate that the degrees of the oxidation of or damage to the biomolecules by the mobilized metals were higher with PM2.5 than with PM10. Therefore, it is expected that more metals mobilized from PM2.5 than from PM10, more damage to the biomolecules by PM2.5 than by PM10. We suggest that when the toxicity of the dust particle is considered, the particle size as well as the mobilizable fraction of the metal should be considered in place of the total amounts.

• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2002년도 Current Trends in Toxicological Sciences
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• pp.89-89
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• 2002

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.155-155
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• 2002

Ambient urban particulate matters contain various transition metals. When the particulate matters are inhaled into the lung, not all but some part of metals from the particles might be mobilized to participate in a reaction that can damage various biomolecules, such as DNA and proteins. The dust particle size as well as organic acids may influence the metal mobilization. Thus, the mobilization of the metal from SRM1648 (NIST, USA) and urban particulate matters (PM2.5 and PM10) was measured in the presence of artificial or biological chelator with or without reductant. The degree of the mobilization was higher with the artificial or biological chelator than the control with saline. In some cases, a reductant increased the mobilization as much as about 5 times the control without the reductant. Especially, the mobilization of Fe was greatly influenced by the presence of reductants. In general, the degree of the mobilization of the transition metal was higher with PM2.5 than with PM10. Therefore, it is expected that, considering the previously known toxicities of the transition metals, the PM2.5 is more damaging to various biomolecules than PM10. The results also suggest that not the total amount but the mobilizable fraction of the metal in the dust particles should be considered with regard to the toxicity of the urban particulate matters.

• Nutrition Research and Practice
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• 제1권1호
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• pp.29-35
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• 2007

Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) $(39.4{\pm}1.5{\mu}M\;vs\;0.61{\pm}10.15{\mu}M)$ and Mn (p<0.05) $(0.74{\pm}0.01{\mu}M\;vs\;0.12{\pm}0.04{\mu}M)$. However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, $12{\mu}M$) except for in the addition of higher $15{\mu}M\;ZnCl_2$ which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion.

• 대한약리학회지
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• 제32권3호
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• pp.425-431
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• 1996

염증 질환의 원인이 되는 사람 중성구 elastases는 혈액에 존재하는 ${\alpha}_1-PI$나 ${\alpha}_2-macroglobulin$과 같은 단백질 분해효소 억제제에 의하여 조절되어진다. 그러나 특수한 병리적 상황에서 과다하게 분비되는 효소나 또는 단백질 분해효소 억제제의 비정상적 작용으로 말미암아 다양한 염증질환이 유발된다. 비스테로이드성 항염증제는 염증 질환을 치료하기 위하여 이미 임상에 적용 하고 있으며, prostaglandin 합성하는 효소인 cyclooxygenases의 활성도를 억제하는 것이 그 작용 기전으로 잘 알려져 왔다. 사람 중성구 elastase의 활성도는 naproxen, phenylbutazone, oxyphenbutazone 등에 의하여 억제되었으나, ibuprofen, ketoprofen, aspirin, salicylic acid, tolmetin 등에 의하여서는 억제되지 않았다. 또한 사람 중성구 elastase의 활성도는 EDTA, EGTA, tetracycline 등에 의하여서도 억제되었다. EDTA에 의하여 2가 이온 $Ca^{++}$나 $Zn^{++}$등을 elastase 분자로부터 일부 제거함으로 효소 활성도가 억제되었고 Raman spectra의 변화도 강하게 일어났으며, 금속이온 $Zn^{++}$를 새로 충진함으로 그 활성도는 원래대로 회복되고 Raman spectrum도 원래 상태와 유사한 상태로 회복되었다. 이런 현상은 chelator나 chelator-like agents가 효소분자안에 존재하는 $Zn^{++}$ 이온을 제거하거나 chelation함으로 활성 부위나 그 인접 부위의 4차원 구조의 변화를 일으켰음에 기인하며 특히 -C=O나 -COOH기의 관여에 의한 것으로 생각된다.

• 대한수의학회지
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• 제47권3호
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• pp.265-271
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• 2007

This study investigated the protective effects of ethylene glycol-bis(${\beta}$-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), an extracellular calcium chelator, and ethylenediaminetetraacetic acid (EDTA), which chelates calcium and most metal ions, against carbon tetrachloride ($CCl_4$)-induced acute hepatotoxicity in mice. Mice were treated with EGTA or EDTA at a dose of 20 (low) or 100 mg/kg (high) subcutaneously 1h before $CCl_4$ administration. The mice were fasted and sacrificed 18h after $CCl_4$ treatment. Blood samples were collected from the carotid artery by decapitation under light ether anesthesia. Serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and cholesterol levels were measured. Malondialdehyde (MDA) production was determined as an index of lipid peroxidation in the liver. The liver, kidneys, and spleen were weighed. We also evaluated the histopathological changes in the liver in each group. The relative weights of the liver were significantly higher in the $CCl_4$-treatment group than in the normal group, except in the high-EDTA treatment group. EGTA and EDTA treatment caused a significant decrease in serum ALP, ALT, and AST levels. Of all of the doses of EGTA and EDTA tested, the high-EDTA dose resulted in the most remarkable inhibitory action. The protective effect in the high-EDTA-treatment group was confirmed histopathologically. The low-EGTA-treatment group showed a significant decrease in serum TG and cholesterol levels. Liver MDA levels were significantly decreased in the EGTA (20 mg/kg) and EDTA (20, 100 mg/kg) groups. These results suggest that EDTA, which chelates both calcium and metal ions, confers better protection in $CCl_4$-induced acute liver damage than does EGTA, a calcium chelator.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.89-89
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• 2002

It is well known that oxygen radicals induce neuronal cell damage by initiation of lipid peroxidation chain reaction. Recent work has been also demonstrated that enzymatically generated free radicals cause the release of glutamate and aspartate from cultured rat hippocampal slices.(omitted)

• 생명과학회지
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• 제10권2호
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• pp.218-227
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• 2000

Bone morphogenetic protein 1 (BMP-1) is part of a complex capable of inducing ectopic bone formation in mammals. Studies on TGF-β1 processing and Drosophila dorsal-ventral patterning have focused attention on BMP-1 as important in mediating the biological activity of this bone inducing complex. Herein, the bacterial expression, refolding, purification, and initial characterization of the BMP-1 proteolytic domain (BPD) are described. A semi-quantitative fluorescence-based thin layer chromatography assay was developed to assist in rapidly screening for optimal renaturation conditions. According to a preliminary screen for optimal conditions for the refolding of BPD , a detectable proteolytic activity against a high turnover substrate for astacin, a homologous protease from crayfish was observed. The conditions identified have allowed the expression of sufficient amounts of BPD for the characterization of the protein. Its proteolytic activity exhibits the same cleavage specificity as astacin against seven substrates that were previously synthesized for studying astacin. Furthermore, this activity is inhibited by the metal chelator 1,10-phenanthroline but not by its analogue 1,7-phenanthroline. The collagenase inhibitor Pro-Leu-Gly hydroxamate was found to inhibit both astacin and BPD activity. The results presented in this paper argue that BMP-1 does in fact possess an intrinsic proteolytic activity.

• Journal of the korean society of oceanography
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• 제34권1호
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• pp.49-57
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• 1999

A red tide organism, Amphidinium carterae was incubated under different iron/chelator and nitrate concentrations to investigate the factors controlling the growth. The chelation capacity played a critical role in regulating the nitrate reductase (NR) activity and in vivo fluorescence of this organism. However, there was a significant difference between the NR activity and in vivo fluorescence in response to trace metals and chelator treatments. In vivo fluorescence was the highest in FeEDTA 10 ${\mu}$M treatments and the lowest in DTPA 10 ${\mu}$M treatments. This indicates that the availability of the trace metal is important in regulating the in vivo fluorescence of this photosynthetic microalgae In contrast, NR activity showed the highest values in trace metal enriched treatments, and trace metal + DTPA treatments showed fairly high NR activities. This suggests that DTPA treatment did not hinder the NR activity as much as it did in vivo fluorescence. In vivo fluorescence and NR activity increased with nitrate concentration of up to 50 ${\mu}$M and remained relatively constant or the rate of increase decreased above that concentration, indicating that initial nitrate concentration of higher than a certain level would not accelerate the growth of A. carterae. Further investigation is needed to elucidate the reason for the difference in timing sequence between the NR and in vivo fluorescence in response to different metal treatments and chelation capacity.