• Title/Summary/Keyword: pH dependent

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Pharmacological characteristics of higenamine on adrenergic β-receptors (아드레날린성 β-수용체에 대한 higemamine의 약리학적 특성)

  • Yun, Hyo-in;Chang, Ki-churl;Lee, Chang-eop
    • Korean Journal of Veterinary Research
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    • v.32 no.1
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    • pp.41-49
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    • 1992
  • Higenamine is an Aconiti tuber derived compound whose chemical structure is 1-(4'-hydroxybenzyl)-6, 7-dihydroxy-1, 2, 3, 4-tetrahydroisoquinoline containing catechol ring and tetrahydroisoquinoline nucleus in its own structure, both of which are well known to have agonistic effects on adrenergic receptors. Using guinea-pig atria(rich in ${\beta}_1$-receptor) and treachea(rich in ${\beta}_2$-receptor), we studied pharmacological actions of higenamine on these organs with special interest of its relevancy of ${\beta}$-receptor selectivity. In order to further clarify its pharmacological characteristics, the influncences of pretreatment of reserpine or cocaine were also investigated. The results were summarized as follows : 1. Higenamine had remarkable chronotropic, inotropic and bronchodilator effects in guinea-pig spontaneously beating right atria, left atria and trachea, in dose-dependent manners. 2. All of above actions were blocked competitively by propranolol, which shows nonselectivity of higenamine on ${\beta}$-receptor. $pA_2$ values of propranolol against higenamine were 7.93, 7.76 and 8.46 in guinea-pig right atria, left atria and treachea, respectively. 3. Reserpine pretreatment(5mg/kg, ip, 24h) did not show my decrease in pharmacological actions of higenamine, which suggests higenamine has direct action on ${\beta}$-receptor not via catecholamine release. 4. Cocaine pretreatment$(1{\mu}M)$ had no influence on pharmacological actions of higenamine in contrast with nor epinephrine, which suggests there is no neuronal uptake mechanism of higenamine in the studied organ preparations.

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Determination of Fermentation Specific Carcinogen, Ethyl Carbamate, in Kimchi (김치에서 발효 식품의 고유 발암원 Ethyl Carbamate 검출)

  • Koh, Eun-Mi;Kwon, Hoon-Jeong
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.421-427
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    • 1996
  • Ethyl carbamate is an animal carcinogen and a suspected human carcinogen found in fermented foods and beverages. For the determination of ethyl carbamate in typical Korean diet, an analytical method was established for the food as complex as Kimchi. Kimchi samples collected from various locations in the country were homogenized and extracted four times with ethyl acelate. Following concentration and reconstitution with water, the extract was loaded onto $C_{18}$ column. Fraction containing ethyl carbamate was eluted with methanol, while most of the red pigment of the sample was retained on the column. The eluent was further purified with alumina, followed by Florisil column. The final eluent was analyzed by gas chromatography mass spectrometry in the selected ion monitoring mode. None of the twenty Kimchi samples showed ethyl carbamate level higher than 4.6 ppb without correction for the recovery. The concentration of ethyl carbamate in Kimchi increased as pH decreased, suggesting fermentation dependent formation of ethyl carbamate.

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Role of Phospholipase $A_2$ in Hypoxia-Induced Renal Cell Injury

  • Choi, Won-Rak;Ko, Sun-Hee;Cho, Su-In;Woo, Jae-Suk;Jung, Jin-Sup;Lee, Sang-Ho;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.1
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    • pp.93-100
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    • 1999
  • The present study was designed to assess the roles of $PLA_2$ activation and arachidonic acid (AA) metabolites in hypoxia-induced renal cell injury. Hypoxia increased LDH release in a dose-dependent manner in rabbit renal cortical slices, and this increase was significant after 20-min hypoxia. The hypoxia-induced LDH release was prevented by amino acids, glycine and alanine, and extracellular acidosis (pH 6.0). Buffering intracellular $Ca^{2+}$ by a chelator, but not omission of $Ca^{2+}$ in the medium produced a significant reduction in hypoxia-induced LDH release. The effect of hypoxia was blocked by $PLA_2$ inhibitors, mepacrine, butacaine, and dibucaine. A similar effect was observed by a 85-kD $cPLA_2$ inhibitor $AACOCF_3.$ AA increased hypoxia-induced LDH release, and albumin, a fatty acid absorbent, prevented the LDH release, suggesting that free fatty acids are involved in hypoxia-induced cell injury. These results suggest that $PLA_2$ activation and its metabolic products play important roles in pathogenesis of hypoxia-induced cell injury in rabbit renal cortical slices.

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Effect of Prostaglandin $E_2$ and Indomethacin on Electrical Activity of Isolated Cat Stomach (적출한 고양이 위(胃)의 전기활동에 미치는 prostaglandin $E_2$ 및 indomethacin의 영향)

  • Kim, Myung-Suk;Lee, Yoon-Lyur
    • The Korean Journal of Physiology
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    • v.17 no.1
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    • pp.63-69
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    • 1983
  • This study was conducted to investigate the effect of prostaglandin $E_2(PGE_2)$ and indomethacin upon the electrical activity of the isolated cat stomach muscle strips$(1.5{\times}7.0\;cm)$. Fifty-seven muscle strips, obtained from 57 cat stomachs(including corpus and antrum) were studied in a muscle chamber filled with Krebs solution(pH 7.4, temperature $36{\pm}0.5^{\circ}C$) aerated with 5% $CO_2$ in $O_2$. The electrical activity was recorded by five capillary electrodes (Ag-AgCl), of which two were placed on the corpus and three on the antrum. After recording of the electrical activity in normal Krebs solution, $PGE_2$ in concentrations of 0.25(N=7), 0.5(=7), 1(N=7) and $2{\times}10^{-7}\;M(N=6)$ were administered to 27 muscle strips, while indomethacin was applied in concentretions of 0.25(N=9), 0.5(N=10), 1(N=6) and $2{\times}10^{-3}\;M(N=5)$ to the remaining 30 strips. The mean frequency were minutely measured from each electrogastrogram. 1) By adding $PGE_2$ in all doses, gastric slow wave frequency increased significantly compared with that in resting state. 2) Following $PGE_2$ administration, peak slow wave frequency increased dose-dependently. 3) After indomethacin addition in all doses, the slow wave frequency decreased significantly compared with that in resting state. 4) Following indomethacin administration, incidence of complete abolition of slow wave increased dose-dependently, and its latent period decreased also in a dose-dependent manner. It is inferred from the above results that prostaglandin $E_2$ has a facilitatory role in the development of gastric slow wave in cat.

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Dinophyceae Fluctuations in Two Alpine Lakes of Contrasting Size During a 10-Year Fortnightly Survey

  • Trevisan, R.;Pertile, R.;Bronamonte, V.;Dazzo, F.B.;Squartini, A.
    • Journal of Microbiology and Biotechnology
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    • v.22 no.6
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    • pp.754-762
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    • 2012
  • Colbricon Superiore and Inferiore are two small adjacent high-mountain lakes located in the Paneveggio Natural Park (Italy) that offer the rare opportunity to study two iso-ecologic water environments differing only by area and volume in a ratio of 2:1 and 3:1, respectively. We took advantage of this setting to investigate phytoplankton dynamics, compare variability and productivity differences between the two basins, and assess size-dependent issues. The phytoplankton group of the Dinophyceae was chosen as the indicator organisms of ecological perturbation owing to their high sensitivity to environmental variations, as well as their acknowledged nature of versatile proxy to report global climatic changes. The study was conducted for over 10 years with fortnightly samplings. Results indicated that (a) the Dinophyceae communities in the smaller lake were significantly more resistant to changes exerted by the fluctuation of lakewater transparency and pH; and (b) the smaller lake sustained a consistently higher production with an average Dinophyceae density 1.73 fold higher than that of the larger lake. The coefficients of variation show that the chemical parameters in the smaller lake display higher time-related fluctuation while being spatially homogeneous and that such conditions correlate with a higher stability of the Dinophyceae assemblage. The use of this setting is also proposed as a model to test relationships between ecosystem production and physical stability.

Anti-inflammatory activity of AP-SF, a ginsenoside-enriched fraction, from Korean ginseng

  • Baek, Kwang-Soo;Hong, Yong Deog;Kim, Yong;Sung, Nak Yoon;Yang, Sungjae;Lee, Kyoung Min;Park, Joo Yong;Park, Jun Seong;Rho, Ho Sik;Shin, Song Seok;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.39 no.2
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    • pp.155-161
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    • 2015
  • Background: Korean ginseng is an ethnopharmacologically valuable herbal plant with various biological properties including anticancer, antiatherosclerosis, antidiabetic, and anti-inflammatory activities. Since there is currently no drug or therapeutic remedy derived from Korean ginseng, we developed a ginsenoside-enriched fraction (AP-SF) for prevention of various inflammatory symptoms. Methods: The anti-inflammatory efficacy of AP-SF was tested under in vitro inflammatory conditions including nitric oxide (NO) production and inflammatory gene expression. The molecular events of inflammatory responses were explored by immunoblot analysis. Results: AP-SF led to a significant suppression of NO production compared with a conventional Korean ginseng saponin fraction, induced by both lipopolysaccharide and zymosan A. Interestingly, AP-SF strongly downregulated the mRNA levels of genes for inducible NO synthase, tumor necrosis factor-${\alpha}$, and cyclooxygenase) without affecting cell viability. In agreement with these observations, AP-SF blocked the nuclear translocation of c-Jun at 2 h and also reduced phosphorylation of p38, c-Jun N-terminal kinase, and TAK-1, all of which are important for c-Jun translocation. Conclusion: Our results suggest that AP-SF inhibits activation of c-Jun-dependent inflammatory events. Thus, AP-SF may be useful as a novel anti-inflammatory remedy.

Preparation and Application of Charcoal-Encapsulated Methyl Silica Microcapsules (활성탄을 함유한 메틸실리카 마이크로캡슐의 제조 및 응용)

  • Ahn, Bok-Yeop;Lee, Yu-Mi;Ham, Myung-Kyung;Rhee, Dong-Seok
    • Journal of Industrial Technology
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    • v.23 no.A
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    • pp.199-206
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    • 2003
  • The charcoal-encapsulated methyl silica microcapsules were prepared by a O/W microemulsion sol-gel method, and the adsorption properties on aquatic humic acid were investigated. The capsules prepared were spherical, $100{\sim}1000{\mu}m$ in size. The size distribution was controllable by adjusting the size of charcoal powder, charcoal/methyl silica ratio, and agitating speed in O/W sol-gel process. Adsorption efficiency of charcoal for aquatic humic acid was decreased after encapsulation by methyl silica shell. The decreased adsorption efficiency can be dependent on the decrease of the BET surface area and pore volume after encapsulation. Diffusion properties of humic acid through the capsule shell also played an important role on adsorption efficiency. Therefore, the reasonable target pollutants for the capsules can be VOC or odor molecules which can overcome diffusion barrier through shell of capsules in air condition. Functionalization methods for the charcoal-encapsulated $CH_3(SiO)_n$ microcapsules by incorporation of $TiO_3$ as a phtocatalytic function and by incorporation of inorganic pigment as a color function were also investigated. $TiO_2$ coating properties were controllable by adjusting pH, temperature, and the concentration of $TiOSO_4$. In XRD measurement, the crystal form of the coated $TiO_2$ was anatase. For the colorization of the capsules, inorganic pigments were more efficient than organic dyes, and various color was introduced to the capsules using inorganic pigments.

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Characterization of Synthetic Polymeric AI(III) Inorganic Coagulants for Water Treatment (상수처리용 합성 무기고분자 Al(III)계 응집제의 화학적특성)

  • Han Seung-Woo;Jung Chul-Woo;Kang Lim-Seok
    • Journal of Environmental Science International
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    • v.8 no.6
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    • pp.711-716
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    • 1999
  • This research explored the feasibility of preparing and utilizing a prefonned polymeric solution of Al(III) for coagulation in water treatment. Slow base(NaOH) injection into supersaturated aluminum chloride and aluminum sulfate solutions did produce high yields of Al polymers useful to water treatment applications. The method of characterization analysis was based on timed spectrophotometer with ferron as a color developing reagent. The hydrolytic Al species were divided into $monomeric(Al_a),\;polymeric(Al_b),\;and\;precipitate(Al_c)$ from the difference in reaction kinetics. The analysis of PACl's characteristics showed that the quantity of polymeric Al produced at value of$ r(OH_{added}/AI)=2.2$ was $83\%$ of the total aluminum in solution, as showing maximum contents and precipitated Al was dramatically increased when r was increased above 2.35. In addition, the characteristics of polyaluminum sulfate (PAS) showed that polymeric Al contained at r = 0.75 was $18\%$ of the total aluminum in solution. The synthesized PACI and PAS were stable during storing period, as indicating negligible aging effect. The effect of sulfate ion on PACI was dependent on the concentration of sulfate ion. That is, polymeric species decrease and precipitate species increase as sulfate ion concentration increased. It can be concluded that the sulfate cause the formation of $Al(OH)_{3(S)}$ at low pH. However, The effect of calcium ion was negligible for distribution of Al species.

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Identification of Anthocyanin from The Extract of Soybean Seedcoat

  • Park, Sun-Mi;Kim, Ji-Na;Dung, Tran-Huu;Do, Le Thanh;Thu, Do Thi Anh;Sung, Mi-Kyung;Kim, Jong-Sang;Yoo, Hoon
    • International Journal of Oral Biology
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    • v.36 no.2
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    • pp.59-64
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    • 2011
  • Anthocyanins are naturally occuring phytochemicals and the main components of the coloring of plants, flowers and fruits. They are known to elicit antioxidative, anti-inflammatory and cancer preventive activity. In this study, we investigated anthocyanins in black / yellow soybean seedcoats using different methods of detection - thin layer chromatography (TLC), capillary zone electrophoresis (CZE) and HPLC analysis. The anthocyanins in soybean seedcoats were extracted by five independent methods of extraction and the aglycons (anthocyanidins) of the corresponding anthocyanins were prepared by acid mediated hydrolysis. The anthocyanin / anthocyanidin in black soybean seedcoat showed characteristic TLC mobility, CZE electrophoretic retention and HPLC migration time while little of anthocyanins were detected from yellow soybean seedcoat. The extracted anthocyanins showed pH dependent retention time in CZE and spectral change in UV-Vis spectrum. HPLC analysis of the hydrolyzed extract of black soybean seedcoat identified the presence of four anthocyanidins. The major anthocyanin in black soybean seedcoat was cyanin (cyanidin-3-O-glucoside), with the relative order of anthocyanidin in cyanidin > delphinidin > petunidin > pelargonidin.

Molecular Dynamics Simulations on β Amyloid Peptide (25-35) in Aqueous Trifluoroethanol Solution

  • Lee, Sang-Won;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.25 no.6
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    • pp.838-842
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    • 2004
  • Amyloid peptide (A${\beta}$) is the major component of senile plaques found in the brain of patient of Alzheimer's disease. ${\beta}$-amyloid peptide (25-35) (A${\beta}$25-35) is biologically active fragment of A${\beta}$. The three-dimensional structure of A${\beta}$25-35 in aqueous solution with 50% (vol/vol) TFE determined by NMR spectroscopy previously adopts an ${\alpha}$-helical conformation from $Ala^{30}$ to $Met^{35}$. It has been proposed that A${\beta}$(25-35) exhibits pH- and concentration-dependent ${\alpha}-helix{\leftrightarrow}{\beta}$sheet transition. This conformational transition with concomitant peptide aggregation is a possible mechanism of plaque formation. Here, in order to gain more insight into the mechanism of ${\alpha}$-helix formation of A${\beta}$25-35 peptide by TFE, which particularly stabilizes ${\alpha}$-helical conformation, we studied the secondary-structural elements of A${\beta}$25-35 peptide by molecular dynamics simulations. Secondary structural elements determined from NMR spectroscopy in aqueous TFE solution are preserved during the MD simulation. TFE/water mixed solvent has reduced capacity for forming hydrogen bond to the peptide compared to pure water solvent. TFE allows A${\beta}$25-35 to form bifurcated hydrogen bonds to TFE as well as to residues in peptide itself. MD simulation in this study supports the notion that TFE can act as an ${\alpha}$-helical structure forming solvent.