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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 62 (1981), S. 183-193 
    ISSN: 1432-1424
    Keywords: gallbladder ; NaCl absorption ; HCO3 ; short-chain fatty acids ; Na/H-exchange ; HCO3/Cl-Exchange ; active transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Gallbladder fluid and electrolyte transport was investigatedin vitro. In guinea pig gallbladder, equimolar substitution of acetate, propionate, butyrate or valerate for HCO3 was increasingly effective in stimulating fluid absorption. The stimulatory potency of these compounds was a function of their chloroform water partition coefficients. The stimulatory effects of the isomers isobutyrate and isovalerate were less than predicted from their partition coefficients. Acidification of the gallbladder lumen, however, was strictly dependent on the partition coefficients for all of the above fatty acids. Unidirectional22Na fluxes were measured in rabbit and guinea pig gallbladders under short-circuit conditions. In the presence of butyrate stimulation of net Na flux was due entirely to an increase in the mucosal-to-serosal Na flux. Stimulation by butyrate was abolished by its omission from the mucosal bathing solution. The transepithelial electrical potential difference in both rabbit and guinea pig gallbladder became more lumen positive following mucosal but not serosal addition of butyrate. Net14C-butyrate fluxes were too small to account for stimulation of Na absorption in either species. Butyrate stimulation of Na absorption by guinea pig gallbladder was abolished by increasing the bathing pH from 7.4 to 8.1. Tris buffer (25mm) partially inhibited butyrate-dependent gallbladder fluid absorption by rabbit and guinea pig at pH 6.4 and 7.0, respectively, and completely at pH 8.4. These results reveal a marked similarity between butyrate and HCO3 stimulation of gallbladder NaCl and fluid absorption. The results are best explained by a double ion-exchange model, in which butyrate (HCO3) in the mucosal solution acts to maintain the intracellular supply of H+ and butyrate (HCO3) for countertransport of Na and Cl, respectively.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 327 (1987), S. 15-16 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 333 (1989), S. 769-770 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The interferences caused by inorganic ions, organic anions and Triton X-100 in the determination of lead by flow injection potentiometric and voltammetric stripping analysis at a mercury film electrode were investigated. The experiments were performed in the concentration range of 1–10 mg/l Pb2+. For both methods linear calibration plots were obtained in the presence of an excess of nitrate, chloride, perchlorate and sulphate. Iodide strongly interferes due to mercury complexation. Metal ion interference caused by formation of irreversible amalgams (as in the case of codeposition of Ni, Co, Fe and Cr) is avoided by proper choice of deposition potential. No effect of water soluble reduced species, i.e. Fe(II) and Cr(II), on the stripping signals was observed. The presence of acetate, citrate and tartrate does not limit the determination of lead by potentiometric stripping analysis (PSA) but has a marked effect on anodic stripping voltammetric (ASV) signals. No influence of Triton X-100 on the determination of lead by PSA was found. In ASV 10−3% Triton X-100 diminished the peak current by 15%.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 40-51 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Production and Reactions of N- MonoalkylamidosulfonylchloridesN-Monosubstituted amidosulfonylchlorides (1) may optimally be obtained by reaction between N-monosubstituted ammonium chlorides and sulfuryl chloride in acetonitrile. N-Monosubstituted amidosulfonylchlorides are very active intermediates, which react especially with reactive H containing compounds to give the free acids 2 (R = H), the esters or thioester 2,5, and 6, and the amides 7 and 8. The hydrogen of the amino group can also be substituted. In this way new compounds are accessible and other already known compounds can be produced more easily.
    Notes: Unter den Methoden zur Herstellung N-monosubstituierter Amidosulfonylchloride (1) erweist sich die Umsetzung von N-monosubstituierten Ammoniumchloriden mit Sulfurylchlorid in Acetonitril als am besten geeignet. N-Monosubstituierte Amidosulfonylchloride sind sehr reaktive Zwischenprodukte, die mit reaktionsfähigen, H-enthaltenden Verbindungen zu den freien Säuren 2 (R = H), den Estern bzw. Thioestern 2, 5 und 6 sowie den Amiden 7 und 8 reagieren können; außerdem besitzen sie einen leicht substituierbaren Wasserstoff an der Amino-Gruppe. Mit ihnen sind Verbindungen präparative leicht zugänglich, die bisher nicht oder nur umständlich gewonnen werden konnten.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
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