• 멤브레인
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• 제26권1호
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• pp.55-61
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• 2016

저압 침지식 멤브레인을 이용한 해수 담수화 전처리에 있어서 유기 파울링은 막간 압력 증가로 인한 화학 세정 횟수의 증가 및 에너지 소비 증가 등 멤브레인 운전시 문제점들을 야기한다. 조류대응 해수전처리에서 조류가 배출하는 extracellular polymeric substances의 대표물질인 sodium alginate를 이용하여 침지식 여과에서 파울링 현상을 관찰하였다. 공기 폭기가 적용되지 않은 경우 순수한 aglinate 파울링은 농도가 증가하면서 증가하였다. 그러나 공기 폭기를 적용해 준 경우 alginate 파울링 감소는 매우 효과적이었다. 공기 폭기가 없는 경우 칼슘 농도의 증가에 따라 alginate 파울링은 감소하였다. 동일 조건에서 공기 폭기 시 높은 alginate 파울링 감소효과를 나타내었으나 NaCl 농도를 증가시킨 경우 칼슘 농도의 증가에 따라 파울링 제어를 위한 공기 폭기 효과는 감소하였다. 해수와 유사한 높은 NaCl과 칼슘 농도에서 고농도 sodium alginate의 경우 공기 폭기량 증가를 통해 초기 파울링을 감소시킬 수 있었으나 시간의 경과에 따라 상대적으로 낮은 폭기량에서의 파울링 감소 효과와 큰 차이는 없었다.

• 생명과학회지
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• 제16권3호
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• pp.433-441
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• 2006

폴리아민은 거의 모든 세포에 있어서 성장과 분화에 필수적인 물질이다. 이들 폴리아민의 기작은 상당히 복잡하고 다양하여 그 정확한 작용기전은 아직 확실하지가 않다. 본 논문에서는 폴리아민이 세포 증식을 유도 하기도 하지만 일정농도 이상에서는 오히려 세포사멸을 초래한다는 결과를 밝히고자 한다. 본 실험에 사용된 인간의 전립선 암세포(LNCaP cells)에 있어서, 폴리아민 가운데 putrescien은 세포 증식에 거의 영향을 미치지 않았으나 spermidine과 spermine의 경우 10 ${\mu}M$ 이하에서는 세포 증식을 촉진하였다. 그러나, 20 ${\mu}M$ 이상의 농도에서는 농도와 시간의존적으로 세포사별을 유도 하였다. 폴리아민 처리에 의한 세포사멸의 초기과정인 핵 응축과 염색질 condensation이 Hoechst와 PI 염색에서 뚜렷이 관찰되었다. 또한, 폴리아민 처리시 anti-apoptotic protein으로 알려진 Bcl-2 protein의 발현은 거의 완전히 억제된 반면, pro-apoptotic protein으로 알려진 Bax의 발현은 현저히 증대되었다. 본 연구의 결과에 따르면, 폴리아민에 의해서 유도되는 세포사멸은 세포 내 칼슘농도 변화에 의한 것으로 사료된다. 전립선 암세포에 있어서 폴리아민 처리시 시간과 농도 의존적으로 세포 내 칼슘농도가 증가되었다. 세포막을 통한 칼슘이동을 억제하는 nifedipine과 flufenamic acid 등의 억제제를 처리한 실험 결과 세포내 칼슘증가는 세포 내부의 저장소로부터 칼슘의 유출보다는 주로 세포막상에 있는 비선택적 칼슘통로를 통한 외부의 칼슘 유입에 의한 것으로 판단된다.

• BMB Reports
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• 제30권2호
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• pp.119-124
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• 1997

Transforming growth $factor-{\beta}\;(TGF-{\beta})$ is a multifunctional polypeptide that exerts biological roles including cell proliferation, differentiation, extracellular matrix deposition and apoptosis in many different cell types. $TGF-{\beta}$, although known as a negative growth regulator, has not been tested in human embryo lung (HEll cells. This study attempts to understand the role of $TGF-{\beta}$ on growth control of HEL cells in relationship to tyrosine phosphorylation pattern of cellular proteins. In density-arrested HEL cells treated with $TGF-{\beta}$, analysis of Western immunoblot showed induction of tyrosine phosphorylation of two major cellular proteins (15 kDa and 45 kDa). In normal proliferating HEL cells with different concentrations of serum, further analysis indicated that the increase in tyrosine phosphorylation of a 45 kDa protein was regulated in serum concentration-dependent manner. However, in proliferating HEL cells treated with $TGF-{\beta}$, tyrosine phosphorylation of 45 kDa was down-regulated. Calcium involvement in the regulation of tyrosine phosphorylation of 45 kDa and 15 kDa proteins was also examined. Tyrosine phosphorylation of 15 kDa protein but not of 45 kDa protein was regulated by exogenous calcium. The level of tyrosine phosphorylation of 15 kDa protein was low at reduced caclium concentration and high at elevated caclium concentration. $TGF-{\beta}$ reversed the pattern of tyrosine phosphorylation of 15 kDa protein. These results suggest that tyrosine phosphorylation of 45 and 15 kDa proteins in HEL cells may be controlled depending on the physiological status of the cells, i.e., low in arrested cells and high in proliferating cells. And the tyrosine phosphorylation of the two proteins appears to be down- or up-regulated by $TGF-{\beta}$.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.169-179
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• 1994

The effect of extracellular and intracellular pH on vascular tone and $^{45}Ca$ uptake were investigated in aortic strips and dispersed single aortic smooth muscle cells of spontaneously hypertensive rats (SHR) and aged-matched Wistar-Kyoto rats (WKY). The contraction produced by a change of extracellular pH (pHo) in the range of $6.5{\sim}8.3$ was estimated by comparison with the level of vascular tone at pH 7.4. Contraction was induced below pHo 6.5 in WKY, pHo 7.1 in SHR, and over pHo 8.0 on both strains. The amplitude of contraction induced by high pHo (over pHo 7.7) was similar in SHR and WKY, but that induced by low pHo (below pHo 7.1) in SHR was greater than that in WKY. Either high pHo- or low pHo-induced contractions in WKY and SHR were not induced in the Ca-free Tyrode's solution and were induced by the addition of Ca. $^{45}Ca$ uptake increased progressively as pHo was increased from 6.8 to 8.1 in the single aortic smooth muscle cells of WKY and SHR. $NH_4Cl$ induced a gradually developing contraction in a dose-dependent manner $(5\;mM{\sim}30\;mM)$ and the removal of $NH_4Cl$ induced transient contraction was followed by profound relaxation in the aortic rings of both strains. The contractions induced by $NH_4Cl$ or by the removal of $NH_4Cl$ in SHR were significantly greater than that in WKY. These contractions were not induced in Ca-free Tyrode's solution. $^{45}Ca$ uptake was increased by $NH_4Cl$ (20 mM) and was not changed by the removal of $NH_4Cl$ (20 mM) in the aortic strips of WKY and SHR. As a summary of above results, the vascular tone of SHR was more sensitive to the change pHi and pHo than that of WKY. The contractions induced by change of extracellular or intracellular pH depended on extracellular Ca in the aorta of SHR nnd WKY. However, the Ca uptake was in accord with the changes of contraction but increase in contraction by low pH was not accompanied by an increase in Ca uptake in both strains.

• Biomolecules & Therapeutics
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• 제17권2호
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• pp.175-180
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• 2009

Taurine is the most abundant free amino acid in the retina and transported into retina via taurine transporter (TauT) at the inner blood-retinal barrier (iBRB). In the present study, we investigated whether the taurine transport at the iBRB is regulated by oxidative stress or disease-like state in a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB) used as an in vitro model of iBRB. First, [$^3H$]taurine uptake and efflux by TR-iBRB were regulated in the presence of extracellular $Ca^{2+}$. [$^3H$]Taurine uptake was inhibited and efflux was enhanced under $Ca^{2+}$ free condition in the cells. In addition, oxidative stress inducing agents such as tumor necrosis factor-$\alpha$ (TNF-$\alpha$), lipopolysaccharide (LPS), diethyl maleate (DEM) and glutamate increased [$^3H$]taurine uptake and decreased [$^3H$]taurine efflux in TR-iBRB cells. Whereas, 3-morpholinosydnonimine (SIN-1), which is known to NO donor decreased [$^3H$]taurine uptake. Lastly, TR-iBRB cells exposed to high glucose (25 mM) medium and the [$^3H$]taurine uptake was reduced about 20% at the condition. Also, [$^3H$]taurine uptake was decreased by cytochalasin B, which is known to glucose transport inhibitor. In conclusion, taurine transport in TR-iBRB cells is regulated diversely at extracellular $Ca^{2+}$, oxidative stress and hyperglycemic condition. It suggested that taurine would play a role as a retinal protector in diverse disease states.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.322-328
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• 1995

A thermophilic bacteria showing proteolytic activity against defatted soybean was isolated from soil. It was identified as Bacillus amyloliquefaciens based on its morphological and physiological characteristics. The Bacillus amyloliquefaciens NS 15-4 was cultivated at 50$\circ$C by rotary shaking in a medium containing defatted soybean. An extracellular protease from this strain was purified to homogeneity by ammonium sulfate precipitation, ion exchange, and hydrophobic interaction chromatographies. The molecular weight of the enzyme was estimated to be approximately 30,000 by SDS-PAGE and the N-terminal amino acid sequence of the enzyme was turned out to be AQSVPYGISQIKAPA. The optimum temperature and pH for the enzyme reaction were 60$\circ$C and 11, respectively, and its thermostability was increased by the addition of calcium ion. The enzyme was inactivated by phenylmethylsulfonylfluoride, suggesting it be a serine protease. Comparing with other commercial proteases, the enzyme showed relatively high proteolytic activity against defatted soybean, a water-insoluble protein substrate.

• Biomolecules & Therapeutics
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• 제8권1호
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• pp.13-21
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• 2000

The present study was designed to investigate the effect f quinidine on catecholamine (CA) secretion evoked by ACh, high $K^{+}$, DMPP, McN-A343, cyclopiazonic acid and Bay-K-8644 from the isolated perfused rat adrenal gland and to establish the mechanism of its action. The perfusion of quinidine (15-150 $\mu$M) into an adrenal vein for 60 min produced relatively dose- and time-dependent inhibition in CA secretion evoked by ACh (5.32$\times$10$^{-3}$ M), high $K^{+}$ (5.6$\times$10$^{-2}$ M), DMPP (10$^{-4}$ M for 2 min), McN-A-343 (10$^{-4}$ M for 2 min), cyclopiazonic acid (10$^{-5}$ M for 4 min) and Bay-K-8644 (10$^{-5}$ M for 4 min). Furthermore, in adrenal glands pre-loaded with quinine (5$\times$10$^{-5}$ M), CA secretory responses evoked by veratridine (10$^{-4}$ M) was time-dependently inhibited. Also, in the presence of lidocaine (10$^{-4}$ M), which is also known to be a sodium channel blocker, CA secretory responses evoked by ACh, high potassium, DMPP, McN-A-343, Bay-K-8644 and cyclo-piazonic acid were also greatly reduced in similar fashion to that of quinidine-treatment. Taken together, these results suggest that quinidine causes greatly the inhibition of CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization, indicating strongly that this effect may be mediated by inhibiting influx of extracellular calcium and release in intracellular calcium in the rat adrenomedullary chromaffin cells. Furthermore, these findings indicate strongly that this inhibitory action of quinidine appears to be associated to the blocking action of sodium channels at least in CA secretion from the rat adrenal gland.and.

• Archives of Pharmacal Research
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• 제24권3호
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• pp.240-248
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• 2001

The present study was attempted to investigate the effect of quinine on secretion of catecholamines (CA) etroked by cholinergic stimulation and membrane depolarization from the isolated perfused rat adrenal gland. The perfusion of quinine (15-150${\mu}$M) into an adrenal vein for 60 min produced dose- and time-dependent inhibition in CA secretion evoked by ACh ($5.32{\times}10^{-3}M$), high $K^{+}5.6{\times}10^{-2}M$, DMPP ($10^{-4}M$ for 2 min), McN-A-343 ($10^{-4}M$ for 2 min), cyclopiazonic acid ($10^{-5}$ for 4 min) and Bay-K-8644 ($10^{-5}$ M for 4 min). Also, under the presence of pinacidil ($10^{-4}$ M), which is also known to be a selective potassium channel activator, CA secretory responses evoked by ACh, high potassium, DMPP McN-A-343, Bay-K-8644 and cyclopiazonic acid were also greatly reduced. When preloaded along with quinine ($5{\times}10^{-5}M$) and glibenclamide ($10^{-6}$ M), a specific blocker of ATP-regulated potassium channels, CA secretory responses evoked by ACh, high potassium, DMPP McN-A-343, Bay-K-8644 and cyclopiazonic acid were recovered as compared to those of quinine-treatment only. taken together, these results demonstrate that quinine inhibits CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization through inhibiting influx of extracellular calcium and release in intracellular calcium in the rat adrenmodullary chromaffin cells. These findings suggest that activation of potassium channels may be involved at least in inhibitory action of quinine on CA secretion from the rat adrenal gland.

• Preventive Nutrition and Food Science
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• 제22권1호
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• pp.9-15
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• 2017

Vaccinium angustifolium, commonly known as the lowbush blueberry, is a rich source of flavonoids, with which various human physiological activities have been associated. The present study focuses on the investigation of the effect of the methanolic extract of V. angustifolium root extract (VAE) on high affinity immunoglobulin E receptor ($Fc{\varepsilon}RI$) ${\alpha}$ chain antibody (CRA-1)-induced allergic reaction in human basophilic KU812F cells. The total phenolic content of VAE was found to be $170{\pm}1.9mg$ gallic acid equivalents/g. Flow cytometry analysis revealed that the cell surface expression of $Fc{\varepsilon}RI$ was suppressed in a concentration-dependent manner upon culture with VAE. Reverse-transcriptase polymerase chain reaction analysis showed that the mRNA level of the $Fc{\varepsilon}RI$ ${\alpha}$ chain was reduced in a concentration-dependent manner as a result of VAE treatment. Western blot analysis revealed that the protein expression of $Fc{\varepsilon}RI$ and the phosphorylation of extracellular signal-regulated kinases (ERK) 1/2 were concentration-dependently inhibited by VAE. We determined that VAE inhibited anti-CRA-1-induced histamine release, in addition to the elevation of intracellular calcium concentration ([$Ca^{2+}$]i), in a concentration-dependent manner. These results indicate that VAE may exert an anti-allergic effect via the inhibition of calcium influx and histamine release, which occurs as a result of the down-regulation of $Fc{\varepsilon}RI$ expression through inhibition of ERK 1/2 activation.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.115-125
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• 1992

An attempt was made to investigate the effect of TMB-8[3, 4, 5-trimethoxybenzoate-8 (N, N-diethylamino) octyl ester], which is known to be an inhibitor of intracellular $Ca^{2+}$ release, on catecholamines (CA) secretion evoked by Ach, excess $K^+$, DMPP, McN-A-343 and caffeine from the isolated perfused rat adrenal glands and to cleaify its mechanism of action. The pretreatment with a low dose of TMB-8 $(10 \mu{M)}$ for 20 min led to marked inhibition in CA secretion evoked by Ach (5.32 mM), excess K^+$ (56 mM), DMPP $(100\;\mu{M)}$, McN-A-343 $(100 \mu{M)}$ and BAY-K 8644 $(10^{-5}M)$. Caffeine-induced CA secretion was simimlar to that of control only during the first periods (0-3 min) but thereafter maked inhibition in CA secretion evoked by caffeine was observed during the rest periods up to 30 min. The increased moderate concentration of TMB-8 $(30 \;\mu{M)}$ caused the result similar to that of $10 \;\mu{M}$ TMB-8. However, in adrenal glands preloaded with a high dose of TMB-8 $(100\;\mu{M)}$, CA releases evoked by Ach, excess $K^+$, DMPP, McN-A-343 and caffeine were almost completely blocked by the drug. These experimental data demonstrate that TMB-8 may inhibit cholinergic receptor-mediated and also depolarization-dependent Ca secretion, suggenesting that these TMB-8 effects seem to be mediated through inhibiting influx of extracellular calcium into the rat adrenal medullary chromaffin cells as well as reducing the release of calcium from intracellular sources.