• Toxicological Research
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• 제11권2호
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• pp.199-203
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• 1995

The focus of this study was to investigate that cellular parameters and glucose uptake might be altered by extracellular calcium and starvation. Addition of 1 mM $Ca^{++}$ to hepatocytes (equalling to the free calcium concentration of blood) significantly increased intracellular $Na^+$ and decreased $Na^+$ & LDH leakage. This pertains to the hepatocytes of control rats as well as those of rats fasted for 24 and 48. hr. These effects might be come from the membrane-stabilizing effects of calcium. But calcium had no effects on cell volumes, superoxide-formation and glucose uptake. Actually hepatocytes of starved rats showed changes in several cellular parameters. Starvation increased LDH leakage, glucose uptake and the total concentration of $Na^+$ and $Na^+$ whereas it markedly decreased cell volumes. Since total tonicity remained unchanged, intracellular $Na^+$ and $Na^+$ could contribute to a higher share of total osmolarity in starvation. Starvation increased the cytoplasmic pH because $R-NH^{3+}$ions and their corresponding counterions disappeared. This increase may be related to suppress the protonization of amino groups in proteins. Starvation decreased hepatic glycogen, a major compound that affects cytosolic volume of hepatocytes. The data indicate that starvation increases the glucose transport activity. The possible molecular basis will be discussed.

• 대한핵의학회지
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• 제36권2호
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• pp.110-120
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• 2002

목적: FDG PET은 악성종양의 진단에 유용하게 쓰이고 있으나, 염증에도 섭취되어 진단에 어려움이 있다. 염증에서 F-18-FDG 섭취는 단핵세포에서 포도당대사가 항진되어 나타난다. 이 연구에서는 사람의 암세포와 단핵세포간에 포도당대사에 차이가 있는지 알아보고자 하였다. 대상 및 방법: 사람의 대장암 세포주(SNU-C2A, SNU-C4, SNU-C5)와 폐암 세포주(NCI-H522), 단핵세포를 포도당 농도가 다른 배지에서 각각 배양시키고, FDG 섭취와 포도당운반체 1(Glut1)의 발현, hexokinase 활성도의 변화를 비교 분석하였다. 결과: 포도당이 없는 배지에서는 암세포와 단핵세포 모두에서 FDG 섭취가 증가되나 포도당 고농도(16.7 mM)에서는 섭취가 감소하였다. 이 고농도에서 Glut1 mRNA의 발현은 대장암 세포주, 폐암 세포주에서 감소하였다. 고농도의 포도당 배지에서 Glut1 단백질의 발현도 4종류의 암세포에서 모두 감소하였으나, 단핵세포에서는 변화가 없었다. SNU-C2A, SNU-C4, NCI-H522 세포에서 hexokinase의 활성도는 비슷하였고, 단핵세포와 SNU-C5에서는 약간 증가하였다. 결론: 포도당 섭취에 있어서 사람의 암 세포주와 단핵세포는 서로 다른 기전을 보이고 있다. 대장암 세포는 포도당 농도에 의한 포도당 섭취 변화가 Glut1에 의하여 조절되나, 단핵세포는 다른 기전을 가지고 있다.

• 한국미생물·생명공학회지
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• 제24권4호
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• pp.485-492
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• 1996

myo-Inositol, a growth factor for Saccharomyces cerevisiae (S. cerevisiae), has been known to be incorporated into phosphatidylinositol (PI), which is a kind of phospholipid in the cell membrane, by a membrane-associated PI-synthesizing enzyme. The deficiency of myo-inositol in S. cerevisiae adversely affected the membrane structure and function. On the basis of biochemical functions of myo-inositol, the effect of deficiency of myo-inositol on the aerobic glucose metabolism was investigated by measuring specific oxygen uptake rate (Q$_{O2}$) used as an indicator representing the respiratory capacity of S. cerevisiae in batch and continuous cultures. The respiratory capacity of aerobic glucose metabolism in S. cerevisiae was also monitored after glucose pulse-addition in a continuous culture (D=0.2, 1/hr), in which glucose was utilized through respiratory metabolism. The deficiency of myo-inositol was found to lead to both the decrease of the maximum specific oxygen uptake rate (Q$_{O2max}$) observed from the batch as well as in the continuous culture experiment and the decrease of the respiratory capacity of aerobic glucose metabolism of S. cerevisiae determined from the glucose pulse-addition experiment, in which the glucose flux into respiratory and fermen- tative metabolism was quantitatively analyzed.

• Journal of Pharmaceutical Investigation
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• 제24권3호spc1호
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• pp.11-18
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• 1994

We have studied the iron uptake by the purified brush-border membrane vesicles (BBMVs) to determine the effect of fructose on the absorption of iron. BBMVs were prepared by the modified calcium precipitation method, The degree of purification was routinely assessed by the marker enzyme, alkaline phosphatase, and the functional integrity was tested by $D-[1-^3H]glucose$ uptake. The appearance of membrane vesicles was shown by transmission electron microscopy (TEM). The uptakes of complexes of labeled iron $[^{59}Fe]$ with fructose and ascorbate were measured with a rapid filtration technique, The uptake rate and pattern of the two iron-complexes, Fe(III)-fructose and Fe(III)-ascorbate, were also observed. A typical overshooting uptake of D-glucose was observed with peak value of $2{\sim}3$ times higher concentration than that at equilibrium. This result was similar to other studies with BBMVs. TEM showed that the size of BBMVs was uniform and we can hardly find any contaminants, Fe(III)-fructose has the higher value of $V_{max}$ and the lower value of Km than those of Fe(III)-ascorbate, respectively. It may be concluded that D-fructose is more effective in promoting the iron absorption than ascorbate.

• Current Research on Agriculture and Life Sciences
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• 제24권
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• pp.29-35
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• 2006

본 연구에서는 갈근 및 그의 주 이소플라본인 puerarin의 활성을 세포 수준에서 분석하였다. 먼저 갈근에 함유된 이소플라본의 양을 분석한 결과, puerarin이 총 이소플라본의 90 % 차지하였다. 다음으로는 puerarin의 항당뇨 활성을 검정한 결과 먼저 탄수화물 및 지방소화효소 저해활성에 대해서는 거의 미비한 것으로 나타났으나 인슐린 감수성 및 지방세포의 분화의 유도에 대해서는 농도 의존적으로 작용하는 것으로 관찰되었다. 따라서 puerarin은 지방조직내로 포도당의 흡수를 촉진함으로서 항당뇨 효능을 발휘하는 것으로 추정된다.

• 약학회지
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• 제40권6호
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• pp.734-738
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• 1996

The development of the alpha2 isoform of (Na,K)ATPase which is high affinity ouabain receptors was studied in the differentiating nonfusing muscle cell line BC3H-1. T he differentiation process of BC3H-1 cell line was confirmed by 2-dexy-D-[$^3$H] glucose uptake experiment and the quantity of the expression of ${\alpha}_2$ isoform was measured using a whole cell [$^3$H] ouabain-binding assay. Undifferentiated growing BC3H-1 cells, myoblasts, exhibited low levels of insulin-stimulated glucose uptake and [$^3$H] ouabain-binding sites. In contrast, differentiated BC3H-1 cells, myocytes, had a 5.6-fold increase in insulin-stimulated glucose uptake and 5-fold increase in [$^3$H] ouabain-binding sites. Scatchard analysis showed that myocytes developed more [$^3$H] ouabain-binding sites than myoblasts vath a dissociation constant (kd) of 6${\times}10^{-8}$M and capacity of 6.l${\times}10^{-5}$ sites/cell. Therefore. it seems that myoblasts express low levels of ${\alpha}_2$ subunit and probably the majority of ${\alpha}_1$ subunit, whereas myocytes express high levels of ${\alpha}_2$ isoform. The results indicate that the expression of ${\alpha}_2$ isoform is developmentally regulated during differentiation and that BC3H-1 culture system provides an excellent model for the study of differentiation and mechanism of (Na,K)ATPase action in muscle which requires electrical excitability.

• 한국식품영양과학회지
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• 제46권1호
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• pp.39-45
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• 2017

본 연구에서는 생산지역별 감초의 물질 표준화를 위해 주요지표성분 중 glycyrrhizic acid를 지표물질로 선정하고 정량분석을 위해 분석법 검증을 수행하였다. 감초의 glycyrrhizic acid의 분석법 검증은 특이성, 직선성, 검출 및 정량한계, 정확성, 정밀성을 구하여 확립하였다. 확립된 분석 방법으로 시험한 국내외 생산지역별 감초의 glycyrrhizic acid 정량 분석 결과 국내산 중에서는 제천산이, 수입산 중에서는 우즈베키스탄산이 각각 16.98, 54.22 mg/g으로 높은 함량을 나타내었다. 또한, 현대인의 심각한 대사질환 중 하나인 당뇨병 예방 및 개선에 효과적인 기능성 천연물 소재를 발굴하고 항당뇨 효과 검증을 위해 생산지역별 감초 에탄올 추출물의 ${\alpha}-glucosidase$ 저해 활성 및 glucose uptake 활성을 평가하였다. ${\alpha}-Glucosidase$ 저해 활성은 국내외 5종 중 제천, 곡성지역의 감초에서 무처리군 대비 높은 저해 활성을 보였고, 우즈베키스탄산은 유의적인 활성이 나타나지 않았다. Glucose uptake 활성의 경우 인슐린 처리를 한 대조군 대비 제천, 영주, 우즈베키스탄 지역의 감초에서 각각 24.19, 27.18, 26.92% 유의적으로 증가함을 확인하였다. 따라서 본 연구의 지표성분 분석, 분석법 검증 결과 및 생리활성 평가는 생산지역별 감초의 물질 표준화 및 품질 평가의 기초자료를 제공하는 데 큰 의미가 있으며, 감초가 대사질환인 당뇨 예방 및 개선에 효과적인 생약식품 소재로의 개발 가능성을 확보하였다. ${\alpha}-Glucosidase$ 저해 활성 및 glucose uptake 활성 평가뿐만 아니라 감초에 함유된 많은 물질연구를 통해 알려지지 않은 활성에 관한 계속된 추후 연구가 필요할 것으로 보인다.

• BMB Reports
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• 제38권4호
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• pp.468-473
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• 2005

The energetics of nitrate uptake by intact cells of the halotolerant cyanobacterium Aphanothece halophytica were investigated. Nitrate uptake was inhibited by various protonophores suggesting the coupling of nitrate uptake to the proton motive force. An artificially-generated pH gradient across the membrane (${\Delta}pH$) caused an increase of nitrate uptake. In contrast, the suppression of ${\Delta}pH$ resulted in a decrease of nitrate uptake. The increase of external pH also resulted in an enhancement of nitrate uptake. The generation of the electrical potential across the membrane ($\Delta\psi$) resulted in no elevation of the rate of nitrate uptake. On the other hand, the valinomycin-mediated dissipation of $\Delta\psi$ caused no depression of the rate of nitrate uptake. Thus, it is unlikely that $\Delta\psi$ participated in the energization of the uptake of nitrate. However, $Na^+$-gradient across the membrane was suggested to play a role in nitrate uptake since monensin which collapses $Na^+$-gradient strongly inhibited nitrate uptake. Exogenously added glucose and lactate stimulated nitrate uptake in the starved cells. N, N'-dicyclohexylcarbodiimide, an inhibitor of ATPase, could also inhibit nitrate uptake suggesting that ATP hydrolysis was required for nitrate uptake. All these results indicate that nitrate uptake in A. halophytica is ATP-dependent, driven by ${\Delta}pH$ and $Na^+$-gradient.

• 한국동물학회지
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• 제11권3호
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• pp.75-82
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• 1968

培養 HeLa 細胞의 酸素消費量과 Lysine 吸收에 미치는 X-線 照射의 영향을 측정하였다. 1. 200r의 X-線 照射는 酸素消費量에 아무러한 영향이 없다. 酸素消費量은 succinate, citrate, 및 $\\alpha$-ketoglutarate에 의하여 增大되며 X-線 照射群에서도 이 傾向은 同一하다. 2. 酸素消費量에 미치는 sodium azide 와 2,4-dinitrophenol 의 영향은 X-線 照射에 의하여 상당히 변화된다. 3. Lysine의 初期吸收率은 X-線 照射에 의하여 甚히 低下되며, 또한 飽和吸收量도 減少된다. 4. Glucose는 lysine의 吸收를 促進시키고, succinate는 아무러한 영향이 없으며 citrate와 $\\alpha$-ketoglutarate는 억제한다. X-線 照射는 이러한 傾向에 아무런 변화를 초래하지 않는다. 5. Lysine의 吸收에 미치는 sodium azide와 2,4-dinitrophenol의 영향은 酸素消費量에 미치는 이들의 영향과 判異하다. 이러한 傾向은 X-線 照射群에서도 대체로 동일하다.

• 대한의생명과학회지
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• 제11권4호
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• pp.487-492
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• 2005

The baculovirus/insect cell expression system is of great value in the study of structure-function relationships in mammalian glucose-transport proteins by site-directed mutagenesis and for the large-scale production of these proteins for mechanistic and biochemical studies. Spodoptera frugiperda Clone 21 (Sf2l) cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, very little is known about the properties of the endogenous sugar transporter(s) in Sf2l cells, although a saturable transport system for hexose uptake has been previously revealed in the Sf cells. In order to further examine the substrate and inhibitor recognition properties of the Sf2l cell transporter, the ability of hexoses to inhibit 2-deoxy-D-glucose (2dGlc) transport was investigated by measuring inhibition constants $(K_i)$. The $K_i's$ for reversible inhibitors were determined from plots of uptake versus inhibitor concentration. Transport was effectively inhibited by D-mannose and D-glucose. Of the hexoses tested, L-glucose had the least effect on 2dGlc transport in the Sf2l cells, indicating that the transport is stereoselective. Unlike the human HepG2 type glucose transport system, D-mannose had a somewhat greater affinity for the Sf2l cell transporter than D-glucose, implying that the hydroxyl group at the C-2 position is not necessary for strong binding. However, epimerization at the C-4 position of D-glucose (D-galactose) resulted in a dramatic decrease in affinity of the hexose for the Sf2l cell transporter. Such a lowering of affinity might be the result of the involvement of the C-4 hydroxyl in hydrogen bonding. It is therefore suggested that Sf2l cells were found to contain an endogenous sugar transport activity that in several aspects resembles the human HepG2 type glucose transporter, although the insect and human transporters do differ in their affinity for cytochalasin B.