LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article ; Online: Effect of azelastine on cardiac repolarization of guinea-pig cardiomyocytes, hERG K⁺ channel, and human L-type and T-type Ca²⁺ channel.

    Park, Mi-Hyeong / Lee, Seung Ho / Chu, Dae Hyun / Won, Kwang Hee / Choi, Bok Hee / Choe, Han / Jo, Su-Hyun

    Journal of pharmacological sciences

    2013  Volume 123, Issue 1, Page(s) 67–77

    Abstract: Azelastine is a second generation histamine H₁-receptor antagonist used as an anti-asthmatic and anti-allergic drug that can induce QT prolongation and torsades de pointes. We investigated the acute effects of azelastine on human ether-a-go-go-related ... ...

    Abstract Azelastine is a second generation histamine H₁-receptor antagonist used as an anti-asthmatic and anti-allergic drug that can induce QT prolongation and torsades de pointes. We investigated the acute effects of azelastine on human ether-a-go-go-related gene (hERG) channels, action potential duration (APD), and L-type (I(Ca,L)) and T-type Ca²⁺ current (I(Ca,T)) to determine the electrophysiological basis for its proarrhythmic potential. Azelastine increased the APD at 90% of repolarization concentration dependently, with an IC₅₀ of 1.08 nM in guinea-pig ventricular myocytes. We examined the effects of azelastine on the hERG channels expressed in Xenopus oocytes and HEK293 cells using two-microelectrode voltage-clamp and patch-clamp techniques. Azelastine induced a concentration-dependent decrease of the hERG current amplitude at the end of the voltage steps and tail currents. The IC₅₀ for the azelastine-induced block of the hERG currents expressed in HEK293 cells was 11.43 nM, while the drug inhibited I(Ca,L) and I(Ca,T) with IC₅₀ values of 7.60 and 26.21 μM, respectively. The S6 domain mutations, Y652A partially attenuated and F656A abolished hERG current block. These results suggest that azelastine is a potent blocker of hERG channels rather than I(Ca,L) or I(Ca,T), providing molecular mechanisms for the arrhythmogenic side effects during the clinical administration of azelastine.
    MeSH term(s) Action Potentials/drug effects ; Animals ; Arrhythmias, Cardiac/chemically induced ; Calcium Channels, L-Type/metabolism ; Calcium Channels, T-Type/metabolism ; Cells, Cultured ; Dose-Response Relationship, Drug ; ERG1 Potassium Channel ; Electrophysiological Phenomena/drug effects ; Ether-A-Go-Go Potassium Channels/antagonists & inhibitors ; Ether-A-Go-Go Potassium Channels/chemistry ; Ether-A-Go-Go Potassium Channels/metabolism ; Guinea Pigs ; HEK293 Cells ; Heart Ventricles/cytology ; Histamine H1 Antagonists/adverse effects ; Histamine H1 Antagonists/pharmacology ; Humans ; Myocytes, Cardiac/metabolism ; Myocytes, Cardiac/physiology ; Oocytes ; Patch-Clamp Techniques ; Phthalazines/adverse effects ; Phthalazines/pharmacology ; Protein Structure, Tertiary ; Xenopus laevis
    Chemical Substances Calcium Channels, L-Type ; Calcium Channels, T-Type ; ERG1 Potassium Channel ; Ether-A-Go-Go Potassium Channels ; Histamine H1 Antagonists ; KCNH2 protein, human ; Phthalazines ; azelastine (ZQI909440X)
    Language English
    Publishing date 2013-09-03
    Publishing country Japan
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2104264-0
    ISSN 1347-8648 ; 1347-8613
    ISSN (online) 1347-8648
    ISSN 1347-8613
    DOI 10.1254/jphs.12239fp
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 237: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article ; Online: CO2 absorption and sequestration as various polymorphs of CaCO3 using sterically hindered amine.

    Vinoba, Mari / Bhagiyalakshmi, Margandan / Grace, Andrews Nirmala / Chu, Dae Hyun / Nam, Sung Chan / Yoon, Yeoil / Yoon, Sung Ho / Jeong, Soon Kwan

    Langmuir : the ACS journal of surfaces and colloids

    2013  Volume 29, Issue 50, Page(s) 15655–15663

    Abstract: One aspect of the attempt to restrain global warming is the reduction of the levels of atmospheric CO2 produced by fossil fuel power systems. This study attempted to develop a method that reduces CO2 emissions by investigating the absorption of CO2 into ... ...

    Abstract One aspect of the attempt to restrain global warming is the reduction of the levels of atmospheric CO2 produced by fossil fuel power systems. This study attempted to develop a method that reduces CO2 emissions by investigating the absorption of CO2 into sterically hindered amine 2-amino-2-methyl-1-propanol (AMP), the acceleration of the absorption rate by using the enzyme carbonic anhydrase (CA), and the conversion of the absorption product to stable carbonates. CO2 absorbed by AMP is converted via a zwitterion mechanism to bicarbonate species; the presence of these anions was confirmed with (1)H and (13)C NMR spectral analysis. The catalytic efficiency (kcat/Km), CO2 absorption capacities, and enthalpy changes (ΔHabs) of aqueous AMP in the presence or absence of CA were found to be 2.61 × 10(6) or 1.35 × 10(2) M(-1) s(-1), 0.97 or 0.96 mol/mol, and -69 or -67 kJ/mol, respectively. The carbonation of AMP-absorbed CO2 was performed by using various Ca(2+) sources, viz., CaCl2 (CAC), Ca(OOCCH3)2 (CAA), and Ca(OOCCH2CH3)2 (CAP), to obtain various polymorphs of CaCO3. The yields of CaCO3 from the Ca(2+) sources were found in the order CAP > CAA > CAC as a result of the effects of the corresponding anions. CAC produces pure rhombohedral calcite, and CAA and CAP produce the unusual phase transformation of calcite to spherical vaterite crystals. Thus, AMP in combination with CAA and CAP can be used as a CO2 absorbent and buffering agent for the sequestration of CO2 in porous CaCO3.
    Language English
    Publishing date 2013-12-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/la403671y
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  3. Article: CO2 Absorption and Sequestration as Various Polymorphs of CaCO3 Using Sterically Hindered Amine

    Vinoba, Mari / Bhagiyalakshmi Margandan / Chu Dae Hyun / Grace Andrews Nirmala / Jeong Soon Kwan / Nam Sung Chan / Yoon Sung Ho / Yoon Yeoil

    Langmuir. 2013 Dec. 17, v. 29, no. 50

    2013  

    Abstract: One aspect of the attempt to restrain global warming is the reduction of the levels of atmospheric CO₂ produced by fossil fuel power systems. This study attempted to develop a method that reduces CO₂ emissions by investigating the absorption of CO₂ ...

    Abstract One aspect of the attempt to restrain global warming is the reduction of the levels of atmospheric CO₂ produced by fossil fuel power systems. This study attempted to develop a method that reduces CO₂ emissions by investigating the absorption of CO₂ into sterically hindered amine 2-amino-2-methyl-1-propanol (AMP), the acceleration of the absorption rate by using the enzyme carbonic anhydrase (CA), and the conversion of the absorption product to stable carbonates. CO₂ absorbed by AMP is converted via a zwitterion mechanism to bicarbonate species; the presence of these anions was confirmed with ¹H and ¹³C NMR spectral analysis. The catalytic efficiency (kcₐₜ/Kₘ), CO₂ absorption capacities, and enthalpy changes (ΔHₐbₛ) of aqueous AMP in the presence or absence of CA were found to be 2.61 × 10⁶ or 1.35 × 10² M–¹ s–¹, 0.97 or 0.96 mol/mol, and −69 or −67 kJ/mol, respectively. The carbonation of AMP-absorbed CO₂ was performed by using various Ca²⁺ sources, viz., CaCl₂ (CAC), Ca(OOCCH₃)₂ (CAA), and Ca(OOCCH₂CH₃)₂ (CAP), to obtain various polymorphs of CaCO₃. The yields of CaCO₃ from the Ca²⁺ sources were found in the order CAP > CAA > CAC as a result of the effects of the corresponding anions. CAC produces pure rhombohedral calcite, and CAA and CAP produce the unusual phase transformation of calcite to spherical vaterite crystals. Thus, AMP in combination with CAA and CAP can be used as a CO₂ absorbent and buffering agent for the sequestration of CO₂ in porous CaCO₃.
    Keywords absorbents ; absorption ; adenosine monophosphate ; anions ; bicarbonates ; calcite ; calcium ; calcium carbonate ; calcium chloride ; carbon dioxide ; carbonate dehydratase ; carbonation ; catalytic activity ; crystals ; enthalpy ; fossil fuels ; global warming ; greenhouse gas emissions ; nuclear magnetic resonance spectroscopy ; phase transition ; spectral analysis ; vaterite ; zwitterions
    Language English
    Dates of publication 2013-1217
    Size p. 15655-15663.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021%2Fla403671y
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  4. Article: CO2 mineralization into different polymorphs of CaCO3 using an aqueous-CO2 system

    Chu, Dae Hyun / Bhagiyalakshmi, Margandan / Hyun Baek, II / Jeong, Soon Kwan / Kim, Sung Hyun / Nam, Sung Chan / Vinoba, Mari / Yoon, Yeoil

    RSC advances. 2013 Oct. 21, v. 3, no. 44

    2013  

    Abstract: This study examines a sequestration of CO2 using sterically hindered 2-amino 2-(hydroxymethyl)-1,3-propanediol in the presence and absence of the carbonic anhydrase enzyme to obtain a CaCO3 with a polymorphic crystal composition that depended on the pH, ... ...

    Abstract This study examines a sequestration of CO2 using sterically hindered 2-amino 2-(hydroxymethyl)-1,3-propanediol in the presence and absence of the carbonic anhydrase enzyme to obtain a CaCO3 with a polymorphic crystal composition that depended on the pH, temperature, or mole ratio of the reactants in the reaction mixture. The CO2 loading capacity of amine absorbent was 8.5 fold higher than CO2 saturated in water. The amounts of CO2 and CaCO3 precipitated were quantified using ion-selective electrodes and ion chromatography, respectively. Interestingly, each of the three polymorphs of CaCO3 (calcite, aragonite, and vaterite) were obtained in pure form, regardless of the presence of the enzyme, and reaction parameters, or the presence of additives in the reaction medium. Mg2+ was found to promote the formation of one of the polymorphs, aragonite. The purities and characteristics of the three polymorphs were verified and quantified by XRD. The carbonization yield, surface morphologies and specific characteristics of the three phases were revealed by IC, FE-SEM, FT-IR, and XPS studies. This study suggests conversion of absorbed CO2 to three polymorphs of CaCO3 could be considered as a potential mineralization process.
    Keywords absorbents ; additives ; aragonite ; calcite ; calcium carbonate ; carbon dioxide ; carbonate dehydratase ; carbonization ; ion exchange chromatography ; magnesium ; mineralization ; pH ; specific ion electrodes ; temperature ; vaterite ; X-ray diffraction
    Language English
    Dates of publication 2013-1021
    Size p. 21722-21729.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ISSN 2046-2069
    DOI 10.1039/c3ra44007a
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: Ginsenoside Rg3 activates human KCNQ1 K+ channel currents through interacting with the K318 and V319 residues: a role of KCNE1 subunit.

    Choi, Sun-Hye / Shin, Tae-Joon / Lee, Byung-Hwan / Chu, Dae-hyun / Choe, Han / Pyo, Mi-Kyung / Hwang, Sung-Hee / Kim, Bo-Ra / Lee, Sang-Mok / Lee, Jun-Ho / Kim, Dong-Hyun / Kim, Hyoung-Chun / Rhim, Hye-whon / Nah, Seung-Yeol

    European journal of pharmacology

    2010  Volume 637, Issue 1-3, Page(s) 138–147

    Abstract: The slowly activating delayed rectifier K(+) channels (I(Ks)) are one of the main pharmacological targets for development of drugs against cardiovascular diseases. Cardiac I(Ks) consists of KCNQ1 plus KCNE1 subunits. Ginsenoside, one of the active ... ...

    Abstract The slowly activating delayed rectifier K(+) channels (I(Ks)) are one of the main pharmacological targets for development of drugs against cardiovascular diseases. Cardiac I(Ks) consists of KCNQ1 plus KCNE1 subunits. Ginsenoside, one of the active ingredient of Panax ginseng, enhances cardiac I(Ks) currents. However, little is known about the molecular mechanisms of how ginsenoside interacts with channel proteins to enhance cardiac I(Ks). In the present study, we investigated ginsenoside Rg(3) (Rg(3)) effects on human I(Ks) by co-expressing human KCNQ1 plus KCNE1 subunits in Xenopus oocytes. Rg(3) enhanced I(Ks) currents in concentration- and voltage-dependent manners. The EC(50) was 15.2+/-8.7 microM. However, in oocytes expressing KCNQ1 alone, Rg(3) inhibited the currents with concentration- and voltage-dependent manners. The IC(50) was 4.8+/-0.6 microM. Since Rg(3) acts opposite ways in oocytes expressing KCNQ1 alone or KCNQ1 plus KCNE1 subunits, we examined Rg(3) effects after co-expression of different ratios of KCNE1 and KCNQ1. The increase of KCNE1/KCNQ1 ratio converted I(Ks) inhibition to I(Ks) activations. One to ten ratio of KCNE1 and KCNQ1 subunit is required for Rg(3) activation of I(Ks). Mutations of K318 and V319 into K318Y and V319Y of KCNQ1 channel abolished Rg(3) effects on KCNQ1 or KCNQ1 plus KCNE1 channel currents. The docked modeling revealed that K318 residue plays a key role in stabilization between Rg(3) and KCNQ1 plus KCNE1 or KCNQ1 subunit. These results indicate that Rg(3)-induced activation of I(Ks) requires co-assembly of KCNQ1 and KCNE1 subunits and achieves this through interaction with residues K318 and V319 of KCNQ1 subunit.
    MeSH term(s) Action Potentials/drug effects ; Animals ; Base Sequence ; Catalytic Domain ; Dose-Response Relationship, Drug ; Ginsenosides/pharmacology ; Humans ; Ion Channel Gating/drug effects ; Ion Channel Gating/genetics ; Ion Channel Gating/physiology ; KCNQ1 Potassium Channel/agonists ; KCNQ1 Potassium Channel/chemistry ; KCNQ1 Potassium Channel/genetics ; KCNQ1 Potassium Channel/metabolism ; Lysine/metabolism ; Mutation ; Oocytes/metabolism ; Panax/chemistry ; Potassium Channels, Voltage-Gated/chemistry ; Potassium Channels, Voltage-Gated/genetics ; Potassium Channels, Voltage-Gated/metabolism ; Protein Subunits/chemistry ; Protein Subunits/genetics ; Protein Subunits/metabolism ; Valine/metabolism ; Xenopus laevis
    Chemical Substances Ginsenosides ; KCNE1 protein, human ; KCNQ1 Potassium Channel ; Potassium Channels, Voltage-Gated ; Protein Subunits ; ginsenoside Rg3 (227D367Y57) ; Valine (HG18B9YRS7) ; Lysine (K3Z4F929H6)
    Language English
    Publishing date 2010-07-10
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80121-5
    ISSN 1879-0712 ; 0014-2999
    ISSN (online) 1879-0712
    ISSN 0014-2999
    DOI 10.1016/j.ejphar.2010.04.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 522: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

To top