• 대한화학회지
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• 제38권2호
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• pp.122-128
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• 1994

거대고리 리간드는 금속이온과 선택적으로 결합하는데, 이를 이용하여 에멀젼 액체막을 통한 금속이온의 이동에 관하여 연구를 수행하였다. 금속이온은 유기층에 있는 운반체에 의하여 source phase에서 recevinng phase으로 이동한다. 운반체로는 거대고리 리간드인 $DBN_3O_3$를 사용하였다. 여기에서 에멀젼 액체막을 통한 금속이온의 이동에 관한 요인과 어떤 금속이온의 선택적 분리에 관하여 검토하였다. 금속이온과 거대고리 리간드 그리고 금속이온과 recevinng phase내에 있는 음이온에 대한 안정도 상수를 금속이온의 선택적 이동에 대한 척도로 조사하였다. 납이온이 혼합 용액에서 다른 금속이온보다 높은 이동속도를 나타내었다. Recevinng phases내의 음이온이 금속이온의 이동에 중요한 역할을 한다.Recevinng phases내에 있는 $NO_3^-$을 $S_2O_3^{2-}$대치하면 이동량이 증가함을 보였는데 이는 $Pb^{2-}-S_2O_3^{2-}$상호작용이 $Pb^{2+}-NO_3^-$상호작용보다 크기 때문이다.

• Archives of Pharmacal Research
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• 제29권5호
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• pp.424-429
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• 2006

In the present study, a human mammary epithelial cell (HMEC) culture model was developed to evaluate the potential involvement of carrier-mediated transport systems in drug transfer into milk. Trypsin-resistant HMECs were seeded on $Matrigel^{circledR}-coated$ filters to develop monolayers of functionally differentiated HMEC. Expression of the specific function of HMEC monolayers was dependent of the number of trypsin treatments. Among the monolayers with different numbers of treatment (treated 1 to 3 times), the monolayer treated 3 times (3-t-HMEC monolayer) showed the highest maximal transepithelial resistance and expression of $\beta-casein$ mRNA as an index of differentiation. Transport of tetraethylammonium (TEA) across the 3-t-HMEC monolayer in the basolateral-to-apical direction was significantly higher than that in the apical-to-basolateral direction (p<0.05), whereas such directionality was not observed for p-aminohippurate, suggesting the existence of organic cation transporters, but not organic anion transporters. In fact, expression of mRNAs of human organic cation transporter (OCT) 1 and 3 were detected in the 3-t-HMEC monolayer. These results indicate that the 3-t-HMEC monolayer is potentially useful for the evaluation of carrier-mediated secretion of drugs including organic cations into human milk.

• Molecules and Cells
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• 제25권2호
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• pp.265-271
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• 2008

Single nucleotide polymorphisms (SNPs) are the most common form of human genetic variation. Non-synonymous SNPs (nsSNPs) change an amino acid. Organic anion transporters (OATs) play an important role in eliminating or reabsorbing endogenous and exogenous organic anionic compounds. Among OATs, hOAT4 mediates high affinity transport of estrone sulfate and dehydroepiandrosterone sulfate. The rapid bone loss that occurs in post-menopausal women is mainly due to a net decrease of estrogen. In the present study we searched for SNPs within the exon regions of hOAT4 in Korean women osteoporosis patients. Fifty healthy subjects and 50 subjects with osteoporosis were screened for genetic polymorphism in the coding region of SLC22A11 (hOAT4) using GC-clamp PCR and denaturing gradient gel electrophoresis (DGGE). We found three SNPs in the hOAT4 gene. Two were in the osteoporosis group (C483A and G832A) and one in the normal group (C847T). One of the SNPs, G832A, is an nsSNP that changes the $278^{th}$ amino acid from glutamic acid to lysine (E278K). Uptake of [$3^H$] estrone sulfate by oocytes injected with the hOAT4 E278K mutant was reduced compared with wild-type hOAT4. Km values for wild type and E278K were $0.7{\mu}M$ and $1.2{\mu}M$, and Vmax values were 1.8 and 0.47 pmol/oocyte/h, respectively. The present study demonstrates that hOAT4 variants can causing inter-individual variation in anionic drug uptake and, therefore, could be used as markers for certain diseases including osteoporosis.

• The Korean Journal of Physiology
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• 제21권2호
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• pp.283-289
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• 1987

Uric acid transport across the basolateral membrane of renal proximal tubules was studied in rabbit kidney cortical slices. Uric acid uptake was greater under $O_2$ atmosphere compared to under $N_2$ atmosphere, and was increased with $Na^{2+}$ concentration in incubation medium. Uric acid inhibited PAH uptake but not TEA uptake and did trans-stimulated PAH efflux. PAH also inhibited uric acid uptake. Uric acid uptake was inhibited by harmaline, ouabin, SITS, DIDS and pyrazinoic acid. The inhibition of PAH uptake by these inhibitors also was reasonably comparable to that of uric acid uptake. These results suggest that uric acid was transported across the basolateral membrane of renal tubule by a carrier-mediated process which was by a common transport system with PAH in rabbit.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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• pp.100-103
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• 2000

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidase (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized the enzyme electrode by electropolymerization added some organic solvent. A formative seeds of film growth is delayed by adding ethanol. The delay is induced by radical transfer between ethanol and pyrrole monomer. The radical transfer shares the contribution of dopant between electrolyte anion and GOx polyanion. This may lead to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased. We established qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. It is due to radical transfer reaction. The radical transfer shares the contribution of dopant between small and fast electrolyte anion and big and slow GOx polyanion.

• 대한수의학회지
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• 제37권1호
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• pp.111-117
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• 1997

This study was carried out determine the effect of renal ischemia on amino acid transport in rabbit renal cortical slices. The animal models of renal ischemia induced experimentally by clamping the renal artery. These results were summarized as follows: 1. The uptake of amino acids lysine and ${\alpha}$-aminobutyrate(AIB), dicarboxylate succinate and organic anion PAH in cortical slices was normal or increased after 30 or 60 min of ischemia in vivo. 2. In a 30 min ischemic kidney, the slice uptake of amino acids was returned to the control level by 30 min of reflow. In a 60 or 90 min ischemic kidney, the lysine uptake was returned to the control level after of reflow, but the uptake of AIB and succinate was significantly reduced during reflow period of 30-120 min. 3. Oxygen consumption in cortical slices was increased after 30 min of ischemia but was not altered by 60 min of ischemia. This results indicat that transient ischemia caused increasing of amino acid uptake in renal cortical slices without metabolic disorder of renal proximal tubule.

• 한국전기전자재료학회논문지
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• 제15권7호
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• pp.615-620
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• 2002

In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidise (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized enzyme electrodes by electropolymerization added some organic solvent, such as ethanol and tetrahydrofuran (THF). The formative seeds of film growth was delayed by adding ethanol. The delay was induced by radical transfer between ethanol and pyrrole monomer. The radical transfer reactions shared the contribution of dopants between electrolyte anion and GOx polyanion. This led to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased.

• 폴리머
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• 제29권4호
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• pp.363-367
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• 2005

Iron(III)p-toluenesulfonate를 개시제로 한 3,4-ethylenedioxyaiophene(EDOT)의 중합과정시 여러 가지 유기용매를 첨가했을 때 poly(3,4-ethylenedioxythiophene)(PEDOT)의 전하이동특성이 어떻게 변하는지에 대해 연구하였다. 첨가한 유기용매의 종류는 MeOH, EtOH등의 알콜류와 Acetone, MEK등의 케톤류였으며, 직류 전기전도도 측정시 280 K에서 전도도는 MeOH를 첨가한 시료가 19.5 S/cm로 가장 높았으며, MEK를 첨가한 시료는 $2.2{\times}10^{-9}$S/cm로 각기 다른 전도도를 나타내었다. 유기용매 첨가에 따른 전기전도도의 변화를 설명하기 위해 X-ray diffraction(XRD)를 통한 PEDOT의 구조적 변화를 관찰하였으며, 알콜류를 첨가했을 경우 결정화도가 증가하는 반면, 케톤류의 유기용매를 첨가했을 경우에는 무정형 구조를 가지는 것을 관찰하였다. 또한 X-ray photoelectron spectoscopyocpy(XPS)를 이용하여 S(2p) 피크를 분석한 결과 케톤류를 첨가한 시료의 경우 다른 시료에 비해 도핑레벨이 매우 낮음을 관찰하였다. 이는 유기용매와 PEDOT의 상대이온인 p-toluenesulfonate와의 상호작용으로 인한 것으로 중합시 유기용매의 첨가에 따라 PEDOT의 도핑효율 및 구조가 변화하고 결과적으로 전기전도도가 변화하는 것을 확인하였다.

• The Korean Journal of Physiology
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• 제20권2호
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• pp.225-235
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• 1986

가토 근위세뇨관에서 Percoll gradient에 의해 분리한 기저막소포(basolateral membrane vesicle)에서 PAH 이동에 미치는 여러 음이온들의 영향을 rapid filtration technique을 이용하여 관찰하였다. NA-dependent PAH 축적은 용액내 $SO_4$와 $SSO_3$에 의하여 유의하게 억제되었으나 $Cl,\;SCN,\;HPO_4,\;acetate$ 및 oxalate에 의해서는 영향을 받지 않았다. 용액내의 $SO_4$는 상경적으로 PHA 이동을 억제하였다. 소포내 음이온을 부하시킨 후 PAH 이동을 측정했을 때 $acetate,\;SO_4$ 및 PAH의 부하에 의해 PAH 이동은 유의하게 증가되었으며, 소포내 부하되는 $SO_4$농도가 증가함에 따라 PAH 축적은 증가되었다. $SO_4$에 의한 PAH의 trans-stimulation은 Na 농도 경사 존재시 더욱 증가되었으며 이들은 2 mM probenecid 및 1mM SITS에 의해 억제되었다. 이들 결과들은 신피질세뇨관 세포의 기저막에 PAH/음이온 교환에 의해 PAH가 이동되는 기전이 존재한다는 것을 가르킨다. 그러나 PAH 이동에 영향이 없는 음이온들은 PAH/음이온 교환에 기질로써 작용하지 않기 때문인지 아니면 이들 음이온들의 높은 투과성에 인해 나타난 결과인지는 더욱 추구해 보아야 확인될 것으로 생각된다.

• The Korean Journal of Physiology
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• 제22권2호
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• pp.307-318
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• 1988

가토 신장 피질에서 Percoll density gradient방법으로 분리한 basolateral membrane vesicle (BLMV)에서 rapid filtration technique을 이용하여 succinate의 이동 특성을 관찰하였다. $Na^+$은 succinate의 이동을 증가시켜 "overshoot"현상을 보였으며 이러한 효과는 $K^+,{\;}Li^+,{\;}Rb^+,{\;}choline$과 같은 다른 양이온들에 의해 나타나지 않았다. $Na^+$농도변화에 따른 succinate의 이동율은 sigmoid모양을 보였고, $Na^+$에 대한 Hill coefficient는 2.0이었다. soccinate의 이동은 vesicle 내부가 음전압일 때 더욱 증가되었다. BLMV에서 succinate이동은 용액내 pH변화에 따라 영향을 받았으나 brush border membrane vesicle (BBMV)에서는 영향을 받지 않았다. 동력학적 분석결과 succinate의 Km값은 $15.5{\pm}0.94{\;}{\mu}M$이었고 Vmax는 $16.22{\pm}0.25{\;}n{\;}mole/mg{\;}protein/min$이었다. succinate의 이동은 $4{\sim}5$탄소를 가진 dicarboxylate들에 의해 강력하게 억제되었으나 monocarboxylate나 다른 유기음이온들에 의해 영향을 적게 받거나 받지 않았다. succinate의 이동은 DIDS, SITS, furosemide와 같은 음이온 이동 억제제와 harmaline과 같은 $Na^+$ 이동 억제제에 의해 억제되었다. 이들 결과들은 BLMV에서 succinate는 $Na^+$에 의존하여 이동하며 다른 Krebs cycle중간 산물들과 동일한 운반기전을 이용함을 가르킨다. 또한 BLMV에서 succinate의 이동은 그 기질특이성에 있어서 다른 연구자에 의해 보고된 BBMV에서 이동특성과 유사함을 보였다.