• 환경위생공학
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• 제18권2호
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• pp.60-66
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• 2003

This study was carried out to elucidate the preventive mechanism of molybdenum on lead-induced neuropathy, An animal model of lead neuropathy was induced by feeding diet containing lead to Sprague-Dawley rat for three weeks. Four weeks aged Sprague-Dawley rats were divided into four groups : normal control group, 10ppm-lead treated group, 1mg/kg-molybdenum treated group, 10ppm-lead and 1mg/kg-molybdenum treated group. The parameters on neuropathy were examined by measuring concentration of myo-inositol and myo-inosito uptake in sciatic nerve. In the lead-treated rats, myo-inositol concentration and myo-inositol uptake rate were reduced by from 54% to 33% respectively. This deficit results from that myo-inositol uptake system which is carrier mediated and sodium-potassium dependent was inhibited by the lead treatment. However, the molybdenum administration significantly eliminated the impairment and maintained myo-inositol concentration to about 82% of normal level. These results suggest that lead-induced neurotoxicity was significantly reduced by administration of molybdenum and the mechanism might be partly normalization of myo-inositol uptake system in sciatic nerve.

• Archives of Pharmacal Research
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• 제21권2호
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• pp.113-119
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• 1998

Changes in the release and uptake of glutamate in cerebellar granule and glial cells of offspring of lead-exposed mothers were determined. In cultured cerebellar granule cells exposed to lead for 5 days, glutamate release was less influenced upon N-methyl-D-aspartate (NMDA) stimulation than that in the control. Although the NMDA-stimulated release of glutamate in cerebellar granule cells prepared from lead-exposed first generation pups was not different from that of the control group, the S-nitroso-N-acetylpenicillamine (SNAP)-stimulated release of glutamate in cerebellar granule cells obtained from lead-treated pups was less elevated than that in the control. Furthermore, in cerebellar granule cells obtained from lead-exposed second generations pups, glutamate release did not respond to both NMDA and SNAP stimulation. In cerebellar glial cells exposed to lead, the basal glutamate uptake was not changed. However, the L-trans-pyrollidine-2,4-dicarboxylic acid (PDC)-blocking effects was significantly reduced. In glial cells obtained from lead-exposed pups, the glutamate uptake was also less blocked by PDC than that in the control. Further decreases in PDC-blocking effects were observed in cerebellar glial cells obtained from lead-treated second generation pups compared to those from the control group. These results indicate that lead exposure induces the changes in the sensitivities of the glutamate release and uptake transporter. In addition, these results suggest that lead exposure might affect the intracellular signalling pathway and transmission in glutamatergic nervous system.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• 환경생물
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• 제18권2호
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• pp.255-262
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• 2000

Synaptosome에 의한 [$^3$H]-serotonin의 일반적인 흡수특성과 이 과정에 납이 미치는 영향을 in vitro와 in vitro에서 관찰하였다. 흰쥐의 대뇌와 뇌간에서 각각 분리한 synaptosome의 흡수친화력은 대뇌가 Km=0.5$\mu$M, 뇌간이 Km=0.1$\mu$M로 모두 고친화성 흡수였고 뇌간에서 더 높았다. 또한 이 흡수과정에 sodium과 potassium이온이 영향을 미치는 것으로 나타났다. Synaptosome이 [$^3$H]-serotonin을 흡수하는 과정은 납에 의해 억제되었고 이러한 납의 독성영향은 in vitro와 in vitro에서 유사한 결과를 보였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.211-211
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• 1996

Changes in glutamate release and uptake on cerebellar cells after the chronic exposure to lead were investigated. Rats were received 0.25% lead acetate in drinking water from the beginning of the pregnancy. The control group was given 0.125% sodium acetate in drinking water. The cerebellar cells from 7 or 8 day-old pups were cultured. Amino acid release from cerebellar granule cells and the glutamate uptake into cerebellar glial cells were measured using HPLC-ECD. Basal glutamate release and NMDA-induced glutamate release didn't show significant difference. However, the other amino acids in the granule cells obtained from lead exposed pups were less released than the control after the stimulation by NMDA (50$\mu$M). SNAP-induced (50$\mu$M) glutamate release was significantly reduced in granule cells prepared from lead exposed pups. The basal glutamate uptake in glial cells didn't show any difference. However, the uptake in glial cells prepared from lead exposed pups was significantly less blocked by PDC (24$\mu$M) compared to the control group. These results indicate that lead exposure to the mother might affect the Excitatory amino acid system during the development of the offspring.

• Applied Biological Chemistry
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• 제44권3호
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• pp.185-190
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• 2001

알긴산은 일반적으로 미생물의 고정화에 널리 사용되는 biopolymer이다. 본 연구는 구연산 생산균인 Aspergillus niger를 calcium alginate로 고정화한 beads로 납의 흡착 특성을 조사하였다. A. niger beads는 $CaCl_2$를 사용하여 주사기로 제조하였으며 이 beads를 납제거에 이용하였다. 그 결과는 다음과 같다. 즉, A. niger를 구연산 생성배지에서 1일에서 7일까지 배양한 후 제조한 beads로 납흡착량을 측정한 결과는 3일간 배양된 곰팡이 beads에서 가장 높았다. 발아되지 않은 beads와 3일간 배양된 beads로 시간에 따른 납흡착량을 정량한 결과 30분까지는 그 흡착량이 동일하게 급격히 증가하였으며 그 후 발아되지 않은 beads는 더 이상 흡착이 일어나지 않았으나 3일간 배양된 곰팡이 beads는 시간이 지남에 따라 천천히 계속 흡착하여 1시간 후에는 480 ppm까지 흡착하였다. 납흡착시 최적 pH와 온도는 각각 6과 $35^{\circ}C$로 나타났다. 납용액 50 ml (500 ppm)이 든 250 ml 삼각플라스크에 beads $50{\sim}100$개가 최적이었으며 그 이상에서는 납흡착율이 감소하였다. 중금속에 대한 흡착율은 납> 구리> 카드뮴 순이었으며 0.1 M $CaCl_2$, 0.1 M NaOH 및 0.1 M KOH의 전처리의 효과는 없었으며 0.1 HCI로 곰팡이 bead의 납탈착하여 beads를 재사용이 가능하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.132-135
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• 1997

We prepared capsules containing Saccharomyces cerevisiae and Zoogloea ramigera cells for the removal of lead(II) and cadmium ions. Microbial cells were encapsulated and cultured in the growth medium. The S.cerevisiae cells grown in the capule did not leak through the capsule membrane. The dried cell density reached to 250 g/l on the basis of the inner volume of the 2.0 mm diameter capsule after 36 hour cultivation. The dry whole cell expolymer density of encapsulated Z.ramigera reached to 200 g/L. The capsule was crosslinked with triethylene tetramine and glutaric dialdehyde solutions. The cadmium uptake of encapsulated whole cell expolymer of Z.ramigera was 55mg Cd/g biosorbent. The adsorption line followed well Langmuir isotherm. The lead uptake of the encapsulated S. cerevisiae was about 30 mg Pb/g biomass. The optimum pH of the lead uptake using encapsulated S. cerevisiae was found to be 6. Freundlich model showed a little better fit to the adsorption data than Langmuir model 95 percent of the lead adsorbed on the encapsulated biosorbents was desorbed by the 1 M HCl solution. The capsule was reused 50 batches without loosing the metal uptake capacity. And the mechanical strength of the crosslinked capsule was retained after 50 trials.

• Current Research on Agriculture and Life Sciences
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• 제1권
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• pp.47-53
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• 1983

A strain of Alcaligenes sp. Isolated from the sludge of industrial area was found to uptake 24.1 mg lead/g dried cell during incubation in medium containing 100g/ml of lead. Analyses of cellular subfractions reveal that fractions of cell wall contain 88.6 percent of lead found associated with the cells and the remainder is found associated with the cytoplasmic fraction. Ultrastructural examination of the cells cultured in media containing 500 and 1000g/ml of lead showed no major irregularities between cells of the treated and untreated cultures.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.117.2-117.2
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• 2003

The mechanism by which lead enters glial cells was examined. The uptake of lead reached saturation when assays were performed in buffers at pH 5.5 and 7.4. The Vmax and Km was 2.7 pmoles/mg protein/min and 13.4 M in the buffer at pH 7.4, respectively, whereas the Vmax and Km was 329 fmoles/mg and 8.2 M in the buffer at pH 5.5, respectively. Uptake in a buffer at pH 5.5 but not at pH 7.4 was inhibited by iron. Cells treated with the iron chelator desferoxamine displayed higher levels of the divalent metal transporter mRNA and protein. (omitted)

• 한국환경과학회지
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• 제1권1호
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• pp.97-126
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• 1992

Greenhouse pot experiments were conducted to evaluate the effects of lime, fly ash and ash(from rice straw) on the cadmium and lead translocation from soil to radish. The soils with low metal contents(Cd 1.52 ppd and Pb 25.37ppm) were prepared and high metal contents (Cd 8.99 rpm and Pb 50.81ppm) were prepared and amended with 0.25%, 0.5%, 1.095, 2.055 each of lime, fly ash and ash. Radishes(Raphanus satiuus) were cultivated and cropped on the soils during 25, 50 and 75 days after sprout, and then cadmium and lead contents of radishes were analyzed by roots and tops. The results obtained are as follows. 1. Lime and ash were effective in raising the soil pH, but fly ash was not effective. 2. The growth of radishes were not impaired by the cadmium and lead contamination but, impaired by soil pH 7.5 or more. 3. Cadmium was accumulated very strongly in radishes and the greater concentration was found in tops than roots, but lead showed no evidence of accumulation in radishes. 4. In general, when the concentrations of lime and ash in soils increased, the uptake of cadmium and lead by radishes decreased, and lime was more effective than ash, while fly ash revealed no effect of reducing the translocation of cadmium and lead from soils to radishes. 5. The uptake of cadmium by radishes decreased more effectively than lead and the uptake of Cd or Pb by radishes grown in the soils with high metal contents decreased more effectively than low metal con tents. 6. Cadmium and lead contents of radishes were negatively correlated with soil pH values and the relationship in cadmium content was stronger than that in lead content.