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  • 1
    Electronic Resource
    Electronic Resource
    Electrical properties of renal collecting duct principal cell epithelium in tissue culture (1986)
    Springer
    Pflügers Archiv 406 (1986), S. 380-386 
    Details
    ISSN: 1432-2013
    Keywords: Collecting duct ; Principal cell ; Tissue culture ; Aldosterone ; Amiloride ; Sodium transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Whereas collecting duct epithelium in vivo is composed of principal and intercalated cells, we grew a pure principal cell epithelium using a new technique involving tissue culture. These principal cells were derived from collecting duct anlagen of newborn rabbits. We investigated the electrical properties of such epithelia in a newly designed lucite double-chamber with an inner opening of 0.08 cm2. Our observations were: 1) mean transepithelial resistanceR te was 0.83±0.2 kΩcm2 at 37° C and after preincubation in aldosterone; 2) mean transepithelial potential differenceV te was low and variable under standard conditions and at room temperature but increased to −59.5±4.4 mV (sign referring to polarity of apical surface) after preincubation in 10−6 mol/l aldosterone and at 37° C; 3) 10−6 mol/l amiloride added to the apical perfusion fluid largely abolished thisV te while increasingR te by 120%; 4) experiments with 5×10−3 mol/l BaCl2 in the apical perfusion fluid failed to changeR te andV te significantly. This principal cell epithelium therefore has characteristics of a “tight” epithelium with active sodium transport; however, its electrical properties differ from those of the isolated perfused collecting duct segment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00590940
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  • 2
    Electronic Resource
    Electronic Resource
    Ionic conductances of cultured principal cell epithelium of renal collecting duct (1988)
    Springer
    Pflügers Archiv 412 (1988), S. 434-441 
    Details
    ISSN: 1432-2013
    Keywords: Collecting duct ; Principal cell ; Tissue culture ; Chloride conductivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ionic conductive properties were studied of epithelia of collecting duct principal cells which had been grown in primary tissue culture from renal cortex/capsule explants. When pretreated with aldosterone (10−6 mol/l) and bathed on either surface with isotonic HCO 3 − -free Ringer's solution, the transepithelial voltage,V te, varied between −21 and −72 mV (apical surface negative) while the transepithelial resistance,R te, ranged from 0.4 to 1.5 kΩcm2. By 10:1 step-changes in Na+ concentration the apical cell membrane was shown to have a high conductivity for sodium, inhibitable by amiloride, 10−6 mol/l. However, contrary to observations in natural collecting duct under control conditions, amiloride never reversed the polarity ofV te even at 10−4 mol/l. Both the apical and the basolateral cell membranes were conductive for potassium and both conductivities were inhibitable by Ba2+ (5 mmol/l). 10:1 reduction of apical Cl− concentration strongly hyperpolarizedV te with a monophasic time course suggesting the presence of a paracellular shunt conductance for Cl−. In addition there may be a small Cl− conductance present in the apical cell membrane since apical application of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPAB) at 10−7 mol/l produced a minute but significant hyperpolarization. On the other hand, 10:1 reduction of basolateral Cl− concentration caused a biphasic change inV te (initial depolarization, followed by repolarization) which indicates the presence of a large Cl− conductance in the basolateral cell membrane. The latter was not inhibitable by 10−7 mol/l NPPAB. Higher concentrations of this and of an other Cl− channel blocker produced non-specific effects. In conclusion, our studies of a pure principal cell epithelium confirm findings described for the intact cortical collecting duct and add new information concerning chloride conductivity and related blocking agents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01907564
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  • 3
    Electronic Resource
    Electronic Resource
    Quantitative Bestimmung der Styrol-Metaboliten MandelsÄure und PhenylglyoxylsÄure in Urin mit Hochdruck-Flüssigkeits-Chromatographie und Gas-Chromatographie (1980)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 303 (1980), S. 401-405 
    Details
    ISSN: 1618-2650
    Keywords: Best. von MandelsÄure, PhenylglyoxylsÄure in Harn ; Chromatographie, HPLC/Chromatographie, Gas ; Styrol-Metabolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es werden eine hochdruckflüssigkeits- und eine gas-chromatographische Methode zur quantitativen Bestimmung der Styrol-Metaboliten MandelsÄure und PhenylglyoxylsÄure im Urin beschrieben. Bei beiden Verfahren wird die PhenylglyoxylsÄure wegen der InstabilitÄt ihrer Derivate durch Oxidation mit Wasserstoffperoxid in der Urinprobe quantitativ zur BenzoesÄure decarboxyliert. Nach einer Flüssig-Flüssig-Extraktion werden die SÄuren mit Diazomethan verestert und dann chromatographiert. Die Probenaufarbeitung erfolgt unter den Bedingungen der internen Standardisierung. Zur Trennung der SÄureester wird bei der GLC ein Temperaturprogramm, bei der HPLC die Gradientenelution mit einer Reversed-Phase-SÄule eingesetzt. Die Detektion wird mit einem Flammenionisationsdetektor bzw. mit einem UV-Detektor mit variabler WellenlÄnge vorgenommen. Mit beiden Methoden wurden Urinproben von 24 styrolbelasteten Personen auf ihren MandelsÄure- und PhenylglyoxylsÄure-Gehalt untersucht. Es ergaben sich Korrelationskoeffizienten von r=0,980 bzw. r=0,916 für Mandelbzw. PhenylglyoxylsÄure.
    Notes: Summary In both the procedures described the urinary phenylglyoxylic acid is quantitatively decarboxylated to benzoic acid by means of an oxidation with hydrogen peroxide. After a liquid-liquid extraction and a subsequent methylation of the acids with diazomethane the chromatographic analysis is carried out. Internal standardization is used for both the methods. The gas chromatographic method uses a temperature program for the separation of the acid esters and a double-flame ionization detector for detection. High-performance liquid chromatography applies gradient elution on a reversed-phase column; a UV-detector with variable wave-length is used for detection. Checking of the reliability of both the methods was done by means of a parallel determination of mandelic and phenylglyoxylic acids in urine samples of 24 persons exposed to styrene. This resulted in a correlation coefficient of r=0.980 and r=0.916 for mandelic and phenylglyoxylic acid, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00470000
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    Paper (German National Licenses)
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