• 한국환경보건학회지
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• 제27권2호
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• pp.82-91
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• 2001

This study was carried out to elucidate the protective effect of zinc chloride(ZnCl$_2$) and its mechanism against the immuno-cytotoxicity of methylmercury chloide($CH_3$HgCl). This study was observed in the culture of EMT-6 cells which are originated from mammary adenocarcinoma of Balb/c mouse. Cytotoxicity of metals was measured by cell viability and NO$_2$$^{[-10]}$ , and mitochondrial function was evaluated by adenosine triphosohate (ATP) production. $CH_3$HgCl significantly decreased the sythesis of nitric oxide(NO), ATP and glutathione(GSH) in a dose-dependent manner. ZnCl$_2$ significantly increased the synthesis of GSH in a dose-dependent manner, but synthesis of NO and ATP were not changed. The immuno-cytotoxicity of $CH_3$HgCl was not fully protected when combined addition of ZnCl$_2$, whereas ZnCl$_2$ prior to addition of $CH_3$HgCl completly protected the Hg-induced immuno-cytotoxicity. Similarly, intracellular accumulation of mercury significantly decreased by ZnCl$_2$. Degree of diminution of intracellular mercury was larger in ZnCl$_2$ prior to addition of $CH_3$HgCl than in combined addition of ZnCl$_2$ and $CH_3$HgCl.. Dithiothreitol(DTT) or buthionine sulfoximine(BSO) addition at 50$\mu$M or less, which was not toxic to the cells, did not affect synthesis of NO and ATP. DTT increased intracellular GSH level and DTT pretreatment protected toxicity induced by $CH_3$HgCl as shown complete recover in the NO and ATP values. BSO decreased intracellular GSH level and BSO pretreatment exaggerated toxicity induced by $CH_3$HgCl as shown synergistic reduction in the NO and ATP values. These results indicated that the protective effects of zinc against immuno-cytotoxicity of methylmercury associated with increasing cellular level of GSH. Increased intracellular GSH transports methylmercury to out of cells. In accordance with intracellular level of mercury decreased, immuno-cytotoxicity of methylmercury decreased. These result also suggest that the protective mechanism of zinc against the mercury toxicity would be exerted in the immune system in vivo.

• Journal of Preventive Medicine and Public Health
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• 제25권1호
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• pp.13-25
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• 1992

This study was conducted to investigate the mechanism of protective effect by sodium selenite in methylmercuric chloride neurotoxicity, increasing intracellular $Ca^{2+}$concentration of the neuron. Methylmercuric chloride of 3mg/kg of body weight was administered simultaneously with sodium selenite of 5mg/kg and pretreatment of sodium selenite via intraperitoneal injection to rats. Also, effect of methylmercuric chloride($25{\mu}M,\;50{\mu}M,\;100{\mu}M$) and sodium selenite($200{\mu}M$) on free intrasynaptosomal $Ca^{2+}$ concentration were studied using the fluorescent $Ca^{2+}$ indicator fura -2 in vitro. After the treatment, at 6, 24, and 48 hours later, mercury in the cerebral cortex, liver and kidney tissues, succlnic dehydrogenase activities, adenosin-5'-triphosphate concentration, acetylcholinesterase activities, and intracellular $Ca^{2+}$ concentration in the cerebral cortex were determined in vivo. Cerebral synaptosomes of rats were incubated with methylmercuric chloride and sodium selenite in Hepes buffer for 10 minutes and free intrasynaptosomal $Ca^{2+}$ concentration were measured with fura-2 in vitro. The results were summarized as follows ; 1. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time significantly more increased in the cerebral cortex and decreased in the liver, kidney mercury concentrations compared to the administration of $CH_3HgCl$ only. 2. The combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ increased more succinic dehydrogenase and acetylcholinesterase activities compared to the administration of $CH_3HgCl$ only. Particularly pretreatment of $Na_2SeO_3$ significantly more compared to the administration of $CH_3HgCl$ only. The concentration of adenosine-5'-triphosphate in $Na_2SeO_3$ treatment groups revealed a favourable effect compared to the administration of $CH_3HgCl$ only. 3. Intracellular $Ca^{2+}$ concentration in administration of $CH_3HgCl$ only was increased significantly more than control group in all test hours but was increased significantly more at 48 hours only after treatment in combined administration of $CH_3HgCl$ and $Na_2SeO_3$ and pretreatment of $Na_2SeO_3$ according to time interval more decreased significantly intracellular $Ca^{2+}$ concentration compared to the administration of $CH_3HgCl$ only. 4. Free intrasynaptosomal $Ca^{2+}$ concentration in the combined administration of $CH_3HgCl$ and $Na_2SeO_3$ was decreased ($24%{\sim}40%$) significantly more than the administration of $CH_3HgCl$ only. From the above results, the specific dosage of $Na_2SeO_3$ decreased increment of intracellular $Ca^{2+}$ concentration induced by administration of $CH_3HgCl$. These findings suggest the protective mechanism of $Na_2SeO_3$ on the neurotoxicity of $CH_3HgCl$.

• 대한화학회지
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• 제36권4호
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• pp.565-578
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• 1992

수용액 및 유기용매-물 혼합용매속에서 L이 $NH_3$, $NH_2$$CH_3$, $glyOC_2H_5$, $glyOCH_3$, $dl-alaOC_2$$H_5$, $NH_2$$CH_2$$CONH_2$, $NH_2$CH$_2$CN 이 배위된 cis-[Co(en)$_2$(L)Cl]$^{2+}$ (en = 1,2-diaminoethane)에 $Hg^{2+}$을 작용시켰을 때 속도론적인 자료, 원평광이색성 스펙트라, 이온교환 크로마토그래피에 의한 생성물 분석 및 용매의 성질인 Y(ionizing power)를 이용한 m(Grunwald-Winstein의 기울기)값의 결과들로 부터 반응은 I$_{d-}$메카니즘으로 제안되었다. 반응 결과 L이 $NH_3$과 NH$_2$CH$_3$이 배위된 cis-[Co(en)$_2$(L)Cl]$^{2+}$은 Cl$^-$이 해리되어 H$_2$O 분자가 치환되었으며, L이 glyOC$_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, NH$_2$CH$_2$CONH$_2$과 NH$_2$CH$_2$CN이 배위된 cis-[Co(en)$_2$(L)Cl]$^{2+}$은 Co(Ⅲ)에 대한 각 리간드 L의 킬레이트화가 일어났다. 에탄올-물 혼합용매 속에서 cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$을 제외한 cis-[Co(en)$_2$(L)Cl]$^{2+}$은 에탄올의 양이 증가될수록 속도상수(k)의 값이 증가되었고, 또한 30${\%}$ 유기용매-물 혼합용매 속에서의 속도상수의 값은 30${\%}$ 2-프로판올-물>30${\%}$ 에탄올-물>물의 순서를 나타내었다. 그러나 cis-[Co(en)$_2$(NH$_2$CH$_2$CN)Cl]$^{2+}$은 이와 반대의 결과를 나타내었다. 각 착물들의 속도상수의 차이에 있어서 cis-[Co(en)$_2$(NH$_3$)Cl]$^{2+}$ 및 cis-[Co(en)$_2$(NH$_2$CH$_3$)Cl]$^{2+}$은 리간드장 파라메타(${\Delta}$)와 관계가 있었지만, cis-[Co(en)$_2$(L)Cl]$^{2+}$(L = $glyOC_2$H$_5$, glyOCH$_3$, dl-alaOC$_2$H$_5$, $NH_2$CH$_2$CONH$_2$, $NH_2$CH$_2$CN)은 이와 관계가 없었다. cis-[Co(en)$_2$(L)Cl]$^{2+}$에 대하여 $NO_3^-$을 첨가시켜 $Hg^{2+}$이 촉매로서 작용하는 반응에서 $NO_3^-$에 의하여 그 반응 메카니즘이 변화되는 것이 아니라 단지 속도만 변화되었다.

• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.245-250
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• 1984

Reciprocal exchanges of DNA in sister chromatids (SCEs) are induced by various carcinogens and mutagens, although the quantitative relationship between the number of mutations and SCEs induced varies among chemicals. Nevertheless, the analysis of SCEs production by various agents often proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity. Mercury, even if which has no evidences for mutagenicity and carcinogenicity, is reported to exert some cytotoxic effects, such as chromosomal aberrations or bad influences to ovulation and reproduction in experimental animals, etc.. In this study, tests for sister chromatid exchanges have been carried out on normal human lymphocytes in whole blood culture to add mercury chloride ($HgCl_2$) or methylmercury chloride ($CH_3\;HgCl$) for 72 hr. The results indicate the dose-dependent relationship between the frequencies of SCEs and the concentrations of $HgCl_2,\;CH_{3}HgCl$ and 5-bromo-2'-deoxyuridine (BrdU). Lymphocyte proliferation has depressed in the higher concentration of mercury.

• 대한화학회지
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• 제34권5호
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• pp.438-444
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• 1990

촉매로서 Hg$^{2+}$을 사용한 수화반응에서 cis-[Co(en)$_2$(OH$_2$)Cl]$^{2+}$, [Co(NH$_3$)$_5$Cl]$^{2+}$, cis-[Co(NH$_3$)$_4$(OH$_2$)Cl]$^{2+}$ 및 [Co(NH$_2$CH$_3$)$_5$Cl]$^{2+}$착물들은 Hg$^{2+}$의 농도가 증가할수록 관측속도상수(k$_{obs}$)의 값이 증가하였다. Hg$^{2+}$에 의한 수화반응의 속도법칙은 Rate = k$_2$K[complex][Hg$^{2+}$]이었고, 그 메카니즘이 연구되었다. 또한 여러가지 유기용매-물 혼합용매에서 Co(Ⅲ)착물의 Hg$^{2+}$에 의한 수화반응이 연구되었다. 용매의 성질인 Y (solvent ionizing power)값에 대한 log k를 도시하여 그 기울기인 m값을 얻었다. 그 m값으로부터 수화반응의 메카니즘을 추정하였다. 속도론적인 자료로부터 Hg$^{2+}$에 의한 Co(Ⅲ)착물의 수화반응이 I$_{d^-}$메카니즘으로 제안되었다. 각 Co(Ⅲ)착물의 속도의 차이는 여러가지 리간드가 배위된 Co(Ⅲ)착물의 리간드장파라메타(${\Delta}$)값과 관계가 있었다.

• 대한화학회지
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• 제41권8호
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• pp.392-398
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• 1997

무기수은과 유기수은을 분리하여 각각을 정량하는 방법을 연구하였다. 고분자량 알킬의 4차아민의 염, Aliquat 336의 $CHCl_3$ 용액을 이용하여 수용액 중에 함유된 무기수은이온, $Hg^{2+}$을 티오시안 착이온으로서, 그리고 유기수은 화합물, $CH_3HgCl$ 및 $C_2H_3O_2$ $HgC_6H_5$ 등을 동시에 추출농축한 다음 무기수은은 3 M $HClO_4 $ 용액으로 선택적인 역추출을 하여 CVAAS로 정량하고, 유기수은은 추출액의 $CHCl_3$ 을 증발 제거한 후 그 찌끼를 4% $KMnO_4 $-1M $H_2$$S0_4 $ 용액으로 분해하여 무기수은 이온으로 만들어서 역시 CVAAS로 정량하였다. 시료용액 50 mL 중에 함유된 Hg로서 1 ${\mu}g$의 무기수은과 유기수은 혼합용액(0.02 ${\mu}gHg/mL$)을 분석한 결과 절대오차 ${\pm}6%$ 이내의 결과를 얻었다.

• 한국환경보건학회지
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• 제22권1호
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• pp.91-98
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• 1996

산업장이나 생활환경에서 접하기 쉬운 수용성 염화물을 중심으로 19개 원소 24종의 금속화합물이 Chinese Hamster Don 세포에 있어서의 sister chromatid exchange(SCE) 출현빈도에 미치는 영향을 조사하였다. Chinese Hamster Don 세포에 대한 자매염색분체 교환출현빈도의 증가가 $CrO_3, K_2CrO_4, K_2Cr_2O_7, MnCl_2, K_2SeO_3, CH_3HgCl$ (p<0.01), $CoCl_2, Na_2HAsO_4, HgCl_2$ (p<0.05) 9종의 금속화합물에서 나타났으며, dose-response relationships이 현저한 금속화합물은 6가 크로화합물과 $K_2SeO_3$이었다.

• Toxicological Research
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• 제29권4호
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• pp.235-240
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• 2013

Extracellular accumulation of amyloid beta protein ($A{\beta}$) plays a central role in Alzheimer's disease (AD). Some metals, such as copper, lead, and aluminum can affect the $A{\beta}$ accumulation in the brain. However, the effect of mercury on $A{\beta}$ accumulation in the brain is not clear. Thus, this study was proposed to estimate whether mercury concentration affects $A{\beta}$ accumulation in PC12 cells. We treated 10, 100, and 1000 nM $HgCl_2$ (Hg) or $CH_3HgCl_2$ (MeHg) for 48 hr in PC12 cells. After treatment, $A{\beta}_{40}$ in culture medium increased in a dose- and time-dependent manner. Hg and MeHg increased amyloid precursor protein (APP), which is related to $A{\beta}$ production. Neprilysin (NEP) levels in PC12 cells were decreased by Hg and MeHg treatment. These results suggested that Hg induced $A{\beta}$ accumulation through APP overproduction and reduction of NEP.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1429-1434
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• 2013

A synthesis and cation-induced fluorescent behavior of the carbazole-attached $NO_2S_2$-macrocycle (L) is described and structurally characterized by single crystal X-ray analysis. The photoluminescence spectrum of L in 80% $CH_3CN/CH_2Cl_2$ displays a peak maximum at 431 nm (blue emission). In the metal-induced fluorometric experiment, L showed a drastic chelation-enhanced fluorescence quenching (CHEQ) effect only with $Hg^{2+}$ and $Cu^{2+}$. In ESI-mass study, a 1:1 stoichiometry for complexation of L with $Hg^{2+}$ was confirmed, suggesting the unique sensing behavior of the proposed ligand L due to the selective complexation affinity for $Hg^{2+}$. The observed results indicate that L is a promising turn-off type fluoroionophore for $Hg^{2+}$ and $Cu^{2+}$ detections. Additionally, the $Ag^+$ complex of the precursor macrocycle was prepared and its solid structure was crystallographically characterized.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.725-730
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• 2013

An investigation of the coordination behavior of sulfur-containing mixed-donor tribenzo-macrocycles $L^1-L^3$ ($L^1$: 20-membered $O_3S_2$, $L^2$: 20-membered $O_2S_3$, and $L^3$: 23-membered $O_4S_2$) with $d^{10}$-metal ($Ag^+$, $Hg^{2+}$, and $Pb^{2+}$) salts is reported. The X-ray structures of five complexes (1-5) with different structural types and stoichiometries, including mono- to dinuclear species have been determined. Reactions of $L^2$ and $L^3$ with the silver(I) salts ($PF_6{^-}$ and $SCN^-$) afforded two dinuclear 2:2 (metal-to-ligand) complexes with different arrangements: a sandwich-type cyclic dinuclear complex $[Ag_2(L^2)_2](PF_6)_2{\cdot}3CH_2Cl_2$ (1) and a linear dinuclear complex $[Ag_2(L^3)_2(SCN)_2]$ (2), in which two monosilver(I) complex units are linked by an Ag-Ag contact. Reactions of $L^1$ and $L^2$ with mercury(II) salts ($SCN^-$ and $Cl^-$) gave a mononuclear 1:1 complexes $[Hg(L^1)(SCN)_2]$ (3) and $[Hg(L^2)Cl_2]$ (4) with anion coordination in both cases. $L^2$ reacts with lead(II) perchlorate to yield a mononuclear sandwich-type complex $[Pb(L^2)_2(ClO_4)_2]$ (5), giving an overall metal coordination geometry of eight with a square antiprism arrangement. From these results, the effects of the donor variation and the anioncoordination ability on the resulting topologies of the soft metal complexes are discussed.