• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.555-563
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• 1997

The effects of pH on $K^+$ currents were investigated in single smooth muscle cells isolated from the thoracic aorta of Wistar-Kyoto rats. Whole-cell $K^+$ currents were recorded in the conventional configuration of the voltage-clamp technique. Pinacidil (10uM) activated the whole-cell current and the pinacidil-activated current was completely inhibited by glibenclamide (10uM) , an inhibitor of ATP-sensitive $K^+$ channel ($K_{ATP}$ channel). Pinacidil-activated current was reversed at near the $K^+$ equilibrium potential. This current was time- and voltage-independent and reduced by elevating intracellular ATP. Pinacidil-activated current was reduced by lowering the external pH. However, alteration of internal pH has controversial effects on pinacidil-activated current. When the single cell was dialyzed with 0.1 mM ATP, alteration of internal pH had no effect on pinacidil-activated $K^+$ current. In the contrast, when the single cell was dialyzed with 3 mM ATP, pinacidil-activated current was increased by lowering internal pH. Our results suggest that $K^+$ channel activated by pinacidil may be $K_{ATP}$ channel and internal $H^+$ may reduce the inhibitory effect of ATP on $K_{ATP}$ channel.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제27권1호
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• pp.26-36
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• 2024

Purpose: We investigated the role of CD8⁺T cells as host immune factors in pediatric patients with Helicobacter pylori gastritis. Methods: Gastric mucosal tissue and blood samples were collected from 39 children, including 11 children with H. pylori infection and 28 children as controls. Anti-CD8 and anti-T-bet antibodies were used for immunohistochemistry of the gastric mucosa. For the cell surface and intracellular staining, peripheral blood mononuclear cells were stained with anti-IL7Rα, anti-CX3CR1, anti-CD8, anti-T-bet, and anti-IFN-γ antibodies. Cytokines of sera such as tumor necrosis factor alpha (TNF-α) and CX3CL1 were analyzed using enzyme- linked immunosorbent assay (ELISA). Results: In the immunohistochemistry of gastric mucosa, the frequency of CD8⁺ and T-bet⁺ T cells cells was higher in the H. pylori-positive group than in the control group (26.9± 7.8% vs. 16.9±3.3%, p<0.001; 5.0±2.5% vs. 2.2±0.7%, p=0.001). Between the control and H. pylori-positive groups, the frequency of IL-7Rα^lowCX3CR1⁺ CD8⁺ and T-bet⁺ INF-γ⁺ CD8⁺ T cells were not significantly different between surface and intracellular staining, respectively (40.4±24.0% vs. 38.2±17.8%, p=0.914; 40.4±24.0% vs. 38.2±17.8%, p=0.914). In the ELISA, no significant differences in TNF-α and CX3CL1 concentrations were observed between the control and H. pylori-positive groups (34.3±12.1 pg/mL vs. 47.0±22.6 pg/mL, p=0.114/0.5± 0.1 pg/mL vs. 0.5±0.1 pg/mL, p=0.188). Conclusion: CD8⁺ T and Th1 cells, which secrete IFN-γ, might play important roles in the mucosal immunity of the stomach in children with H. pylori infection.

• 한국식품영양과학회지
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• 제45권11호
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• pp.1580-1588
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• 2016

잔대의 70% 에탄올 추출물은 강한 항산화 효과 및 산화적 스트레스 조건에서 뇌신경세포 사멸 억제 효과가 있었다. 6개의 분획물 중에 잔대 추출물의 클로로포름 분획물(AT-CH)은 높은 DPPH 라디칼 소거작용 및 세포 내 활성산소종(ROS) 소거작용을 가지고 있었고 $H_2O_2$에 대항하여 뇌신경 세포(SK-N-SH) 보호 효과가 가장 뛰어났다. 활성이 가장 우수한 클로로포름 분획물을 대상으로 주요 물질을 순수분리한 후 $^1H-NMR$, $^{13}C-NMR$ 그리고 EI mass spectra를 이용하여 화학구조를 분석한 결과 phytosterols(${\beta}$-sitosterol과 daucosterol)이라는 것을 알 수 있었다. ${\beta}$-Sitosterol과 daucosterol 역시 산화적 스트레스에 대항하여 SK-N-SH 세포를 보호하는 작용이 있었다. AT-CH 그리고 이것으로부터 분리된 화합물은 p38 경로를 저해하였다. 이들 결과는 AT-CH는 p38 경로를 저해하고 세포 내 ROS 소거작용에 의해 산화적 스트레스로부터 뇌신경세포 보호 효과를 가질 것이라 제안하였다.

• KSBB Journal
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• 제17권6호
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• pp.555-559
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• 2002

프럭토올리고당 합성효소의 생산능력이 우수한 균주를 선발하기 위하여 Aureobasidium pullulan 3종을 배양하여 비교해본 결과 ATCC 9348이 비효소활성 측면에서 가장 우수했으며, 세 균주 모두 균체성장과 효소생산패턴과는 대체적으로 선형적인 관계가 있었다. 균의 형태학적 측면에서 볼 때 배양초기에는 대부분 mycelia cells 형태이었으나 배양이 점차 진행되면서 yeast-like cells 및 chlamydospores 형태로 바뀌었고, 이러한 형태변화와 더불어 균체외효소에 대한 균체내효소의 활성비율도 변화됨을 알 수 있었다. 2.5-L 발효조를 사용하여 pH 영향을 조사해본 결과 pH 7.0 범위에서 효소생산이 최대로 나타났고 pH 4.0 또는 pH 8.0 조건에서는 균체외효소에 대한 균체내효소 활성이 높게 나타나는 것으로 보아 배양조건에 따라 효소의 배출효율이 달라지는 것을 알 수 있었다. 또한 값싼 원료인 당밀로부터 A. pullulans 효소를 사용하여 사료첨가제로서의 프럭토올리고당 생산이 가능함을 확인하였다.

• 한국동물학회지
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• 제19권1호
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• pp.25-32
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• 1976

양서류 발생에 따른 위점막 점액세포의 조직학적 및 조직화학적인 변화를 밝히고저 개구리(Rana nigromaculata)변태 각 단계의 위체부 조직을 10% formalin 완충액에 고정($4^{\circ}C$), paraffin에 포매, 4 $\mu$m 두께로 절편한후 periodic acid-Schiff(PAS) 및 alcian blue(AB) pH 2.5, pH 1.0에 반응시켜 다음과 같은 결과를 얻었다. 1. 위 표면점액세포내 점액질은 변태과정에 따라 특이한 변화없이 PAS에 강한 반응을 AB pH 2.5 및 pH 1.0에서는 약한 alcianophilia를 보였으며, 변태 XXIV와 XXV에서 세포내 중성 점액질의 함량이 현저히 증가하였다. 2. 위소와점액세포는 변태 XXI이후에서 볼 수 있었는데 PAS에 강한 반응을, AB pH 2.5 및 pH 1.0에서 약한 alcianophilia를 보였으나, AB pH 1.0에서는 AB pH 2.5에서 보다 강하였고, 변태 XXIV와 XXV에서 세포내 중성 점액질의 함량이 현저히 증가하였다. 3. 분비능을 보이는 점액질세포는 변태 XXIV이후인데 변태 XXIV에서는 PAS에 강양성을, AB pH 1.0에서는 약한 alcianophilia를 보였고, 변태 XXV 이후에는 PAS에 약한 반응을, AB pH 2.5에는 약하고 AB pH 1.0에는 중등도의 alcianiphilia를 보였는데 이들 점액질은 전 세포질에 비교적 고르게 분포하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제3권1호
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• pp.47-52
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• 1990

During prolonged exposure to the sun for 8 h each day for 10 days in which the highest ambient temperature around 14:00 h was $39^{\circ}C$, buffaloes exposed to the sun without shade increased the turnover of body water by 35% and 76% on day 5 and day 10 of exposure respectively. The total body water markedly decreased on day five and this amount was maintained thereafter. Plasma and blood volumes did not change significantly on day five but markedly decreased on day 10. Packed cell volume significantly decreased on day five and day 10 of the exposure period. The reduction of packed cell volume on day 10 coincided with the decrease in total plasma water. On day 10 of the exposure, an increase in the rate of liquid flow from the rumen was noted. It is concluded that on the fifth day of exposure, the increase in the evaporative cooling process was attributed to initial mobilization of water from the intracellular compartment. The reduction of both plasma and cell volumes occurring from day five to day 10 indicated a loss of body water from both intracellular and extracellular compartments.

• Food Science and Biotechnology
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• 제16권1호
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• pp.167-170
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• 2007

(-)-Epigallocatechin-3-gallate (EGCG), a mai or tea catechin has been shown to have many interesting biological activities. In the present study, we studied the effects of green tea catechins, EGCG metabolites, and black tea theaflavins on accumulation of EGCG in HT-29 human colon cells. Intracellular levels of [$^3H$]-EGCG were not changed significantly in the presence of other tea catechins including (-)-epicatechin, (-)-epigallocatechin, and (-)-epicatechin-3-gallate. EGCG methyl metabolites and EGCG 4"-glucuronide did not affect cellular levels of [$^3H$]-EGCG. Black tea theaflavins and theasinensin A (TsA), an EGCG oxidative dimer, however, significantly decreased cellular accumulation of EGCG in HT-29 cells by 31-56%. This decrease was more pronounced when cells were incubated in the presence of theaflavin-3',3"-digallate (TFdiG) or TsA. When EGCG was added separately from TFdiG or TsA, the accumulation of EGCG in HT-29 cells was also significantly decreased regardless of when TFdiG or TsA was added during the uptake study (p<0.01). The results suggest that theaflavins and TsA may interrupt EGCG absorption through the gastrointestinal epithelium.

• BMB Reports
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• 제50권5호
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• pp.269-274
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• 2017

The biological activities of macrophage migration inhibitory factor (MIF) might be mediated through a classical receptor-mediated or non-classical endocytic pathway. JAB1 (C-Jun activation domain-binding protein-1) promotes the degradation of the tumor suppressor, p53, and the cyclin-dependent kinase inhibitor, p27. When MIF and JAB1 are bound to each other in various intracellular sites, MIF inhibits the positive regulatory effects of JAB1 on the activity of AP-1. The intestinal parasite, Anisakis simplex, has an immunomodulatory effect. The molecular mechanism of action of As-MIF and human JAB1 are poorly understood. In this study, As-MIF and hJAB1 were expressed and purified with high solubility. The structure of As-MIF and hJAB1 interaction was modeled by homology modeling based on the structure of Ace-MIF. This study provides evidence indicating that the MIF domain of As-MIF interacts directly with the MPN domain of hJAB1, and four structure-based mutants of As-MIF and hJAB1 disrupt the As-MIF-hJAB1 interaction.

• The Korean Journal of Physiology
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• 제30권1호
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• pp.63-76
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• 1996

The aim of present study was to characterize phosphate uptake and to investigate the mechanism for the insulin and insulin-like growth factor(IGF) stimulation of phosphate uptake in primary cultured rabbit renal proximal tubule cells. Results were as follows : 1. The primary cultured proximal tubule cells had accumulated $6.68{\pm}0.70$ nmole phosphate/mg protein in the presence of 140 mM NaCl and $2.07{\pm}0.17$ nmole phosphate/mg protein in the presence of 140 mM KCl during a 60 minute uptake period. Raising the concentration of extracellular phosphate to 100 mM$(48.33{\pm}1.76\;pmole/mg\;protein/min)$ induced decrease in phosphate uptake compared with that in control cells maintained in 1 mM phosphate$(190.66{\pm}13.01\;pmole/mg\;protein/min)$. Optimal phosphate uptake was observed at pH 6.5 in the presence of 140 mM NaCl. Phosphate uptake at pH 7.2 and pH 7.9 decreased to $83.06{\pm}5.75%\;and\;74.61{\pm}3.29%$ of that of pH 6.5, respectively. 2. Phosphate uptake was inhibited by iodoacetic acid(IAA) or valinomycin treatment $(62.41{\pm}4.40%\;and\;12.80{\pm}1.64%\;of\;that\;of\;control,\;respectively)$. When IAA and valinomycin were added together, phosphate uptake was inhibited to $8.04{\pm}0.61%$ of that of control. Phosphate uptake by the primary proximal tubule cells was significantly reduced by ouabain treatment$(80.27{\pm}6.96%\;of\;that\;of\;control)$. Inhibition of protein and/or RNA synthesis by either cycloheximide or actinomycin D markedly attenuated phosphate uptake. 3. Extracellular CAMP and phorbol 12-myristate 13 acetate(PMA) decreased phosphate uptake in a dose-dependent manner in all experimental conditions. Treatment of cells with pertussis toxin or cholera toxin inhibited phosphate uptake. cAMP concentration between $10^{-6}\;M\;and\;10^{-4}\;M$ significantly inhibited phosphate uptake. Phosphate uptake was blocked to about 25% of that of control at 100 ng/ml PMA. 3-Isobutyl-1-methyl-xanthine(IBMX) inhibited phosphate uptake. However, in the presence of IBMX, the inhibitory effect of exogenous cAMP was not significantly potentiated. Forskolin decreased phosphate transport. Acetylsalicylic acid did not inhibit phosphate uptake. The 1,2-dioctanoyl-sn-glycorol(DAG) and 1-oleoyl-2-acetyl-sn- glycerol(OAG) showed a inhibitory effect. However, staurosporine had no effect on phosphate uptake. When PMA and staurosporine were treated together, inhibition of phosphate uptake was not observed. In conclusion, phosphate uptake is stimulated by high sodium and low phosphate and pH 6.5 in the culture medium. Membrane potential and intracellular energy levels are also an important factor fer phosphate transport. Insulin and IGF-I stimulate phosphate uptake through a mechanisms that involve do novo protein and/or RNA synthesis and decrease of intracellular cAMP level. Also protein kinase C(PKC) is may play a regulatory role in transducing the insulin and IGF-I signal for phosphate transport in primary cultured proximal tubule cells.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.234-241
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• 2001

The C-terminal 393 bp region of the human interleukin-16 (IL-16) gene was cloned and expressed in E. coli along with mammalian cell lines. Recombinant IL-16 expressed from E. coli was 22 kDa on SDS-PAGE and showed 260% of chemoattractant activity at a concentration of $0.1\;{\mu}g/ml$. HeLa, COS, and Neuro-2a cells were transduced by recombinant retrovirus vector pLNC/IL-16/IRES/TK and the intracellular and secreted amounts of IL-16 produced by HeLa/IL-16/TK, COS/IL-16/TK, and Neuro-2a/IL-16/TK cells were determined by enzyme-linked immunosorbent assay (ELISA). HeLa/IL-16/TK $(1{\times}10^5)$ and COS/IL-16/TK $(1{\times}10^5)$ cells secreted 36.1 and 13.3 ng of IL-16 for 48 h, respectively. Forty-nine ng and 86.4 ng of IL-16 remained in the cell lysates of HeLa/IL-16/TK and COS/IL-16/TK. Intracellular and secreted amounts of IL-16 from Neuro-2a/IL-16/TK $(5{\times}10^5)$ cells during 24 h cultivation were 50 ng and 3.3 ng, respectively. Also, HeLa and COS cells wee stably transfected with mammalian expression vector pCRIII/IL-16. Both culture media and cell lysates prepared from HeLa/IL-16 cells and COS/IL-16 cells showed chemoattractant activity ranging from 190% to 460% as compared to the control experiment. Expression of the herpes simplex virus thymidine kinase (HSV0tk) gene in pLNC/IL-16/ IRES/TK bicistronic retroviral expression vector was verified by performing a genciclovir (GCV) sensitivity assay. Finally, IL-16 repressed Tat-transactivated human immunodeficiency virus type 1 long terminal repeat (HIV-1 LTR) promoter activity.