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  1. Article: Adaptation of Madin-Darby canine kidney cells to hypertonic medium: an electron microprobe analysis.

    Borgmann, S / Dörge, A

    Kidney international. Supplement

    1998  Volume 67, Page(s) S133–5

    Abstract: Madin-Darby canine kidney (MDCK) cells of confluent epithelial sheets grown on permeable supports respond to hyperosmotic stress by short- and long-term regulatory volume increase (RVI). Although short-term RVI includes the uptake of inorganic ... ...

    Abstract Madin-Darby canine kidney (MDCK) cells of confluent epithelial sheets grown on permeable supports respond to hyperosmotic stress by short- and long-term regulatory volume increase (RVI). Although short-term RVI includes the uptake of inorganic electrolytes, long-term RVI does not and seems therefore to result from accumulation of organic osmolytes.
    MeSH term(s) Adaptation, Physiological/drug effects ; Adaptation, Physiological/physiology ; Animals ; Cell Line ; Cryoelectron Microscopy ; Culture Media/pharmacology ; Dogs ; Electron Probe Microanalysis ; Hypertonic Solutions/pharmacology ; Kidney Tubules, Collecting/cytology ; Kidney Tubules, Collecting/metabolism ; Kidney Tubules, Collecting/ultrastructure ; Osmolar Concentration ; Sodium Chloride/pharmacology ; Water-Electrolyte Balance/physiology
    Chemical Substances Culture Media ; Hypertonic Solutions ; Sodium Chloride (451W47IQ8X)
    Language English
    Publishing date 1998-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 193442-9
    ISSN 2157-1716 ; 0098-6577 ; 2157-1724
    ISSN (online) 2157-1716
    ISSN 0098-6577 ; 2157-1724
    DOI 10.1046/j.1523-1755.1998.06725.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: The role of mitochondria-rich cells in sodium transport across amphibian skin.

    Nagel, W / Dörge, A

    Pflugers Archiv : European journal of physiology

    1996  Volume 433, Issue 1-2, Page(s) 146–152

    Abstract: The possible participation of mitochondria-rich cells in transepithelial Na+ transport across frog skin under "physiological conditions" (low apical [Na+], open circuited) was analysed by recording electrophysiological parameters from principal cells ... ...

    Abstract The possible participation of mitochondria-rich cells in transepithelial Na+ transport across frog skin under "physiological conditions" (low apical [Na+], open circuited) was analysed by recording electrophysiological parameters from principal cells with intracellular microelectrodes and using measurement of Rb+ uptake into the epithelial cells from the serosal side via the Na+/K+-ATPase. It was observed that transport perturbation with amiloride induced changes in the apical potential difference and fractional apical resistance in principal cells, observations which are compatible with the notion that the essential fraction of transcellular current flow occurs across these cells. Amiloride-inhibitable uptake of Rb+ was also restricted to principal cells, the amount being about equivalent to the predicted rate of K+ recycling via the Na+/K+-ATPase. The results indicate that principal cells are responsible for transepithelial Na+ transport irrespective of the experimental conditions. Flow of Na+ across mitochondria-rich cells appears to be negligible.
    MeSH term(s) Animals ; Biological Transport/physiology ; Electron Probe Microanalysis ; Microelectrodes ; Mitochondria/physiology ; Rana esculenta/metabolism ; Skin/cytology ; Skin/metabolism ; Sodium/metabolism
    Chemical Substances Sodium (9NEZ333N27)
    Language English
    Publishing date 1996-11
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 6380-0
    ISSN 1432-2013 ; 0031-6768
    ISSN (online) 1432-2013
    ISSN 0031-6768
    DOI 10.1007/s004240050260
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Characteristics of sodium uptake across the basolateral membrane of oxyntic cells.

    Fritzenwanger, M / Heid, I / Dörge, A

    Kidney international. Supplement

    1998  Volume 67, Page(s) S143–5

    Abstract: To characterize further serosal Na uptake into gastric oxyntic cells under resting conditions, cellular element concentrations were determined in isolated frog (Rana temporaria) gastric mucosae using electron microprobe analysis. The epithelia were kept ... ...

    Abstract To characterize further serosal Na uptake into gastric oxyntic cells under resting conditions, cellular element concentrations were determined in isolated frog (Rana temporaria) gastric mucosae using electron microprobe analysis. The epithelia were kept short circuited in Ussing-type chambers, and element analysis was performed on freeze-dried cryosections. After ouabain (10(-4) M), the [Na] in oxyntic cells increased within 30 to 60 minutes from approximately 25 to 100 mmol/kg wet wt, and [K] decreased similarly (from 100 to 25 mmol/kg wet wt). These changes occurred regardless of whether the basolateral incubation medium contained HCO3 or N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) as buffers. When, prior to the addition of ouabain, 10(-3) M amiloride was applied to the serosal side to inhibit the Na-H antiporter, the ouabain-induced increase in cellular [Na] was prevented completely in HEPES-, but not in HCO3-Ringer. The data are compatible with the notion that Na is taken up by a Na-H antiporter and a Na-HCO3 symporter. At least under these experimental conditions, these transporters seem to contribute substantially to basolateral Na uptake in oxyntic cells.
    MeSH term(s) Amiloride/pharmacology ; Animals ; Bicarbonates/metabolism ; Biological Transport/physiology ; Carrier Proteins/metabolism ; Cell Membrane/metabolism ; Diuretics/pharmacology ; Enzyme Inhibitors/pharmacology ; Ouabain/pharmacology ; Parietal Cells, Gastric/chemistry ; Parietal Cells, Gastric/drug effects ; Parietal Cells, Gastric/metabolism ; Rana temporaria ; Sodium/metabolism ; Sodium-Bicarbonate Symporters ; Sodium-Hydrogen Exchangers/metabolism
    Chemical Substances Bicarbonates ; Carrier Proteins ; Diuretics ; Enzyme Inhibitors ; Sodium-Bicarbonate Symporters ; Sodium-Hydrogen Exchangers ; Ouabain (5ACL011P69) ; Amiloride (7DZO8EB0Z3) ; Sodium (9NEZ333N27)
    Language English
    Publishing date 1998-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 193442-9
    ISSN 2157-1716 ; 0098-6577 ; 2157-1724
    ISSN (online) 2157-1716
    ISSN 0098-6577 ; 2157-1724
    DOI 10.1046/j.1523-1755.1998.06728.x
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Cellular site of active K absorption in the guinea-pig distal colonic epithelium.

    Dörge, A / Beck, F X / Rechkemmer, G

    Pflugers Archiv : European journal of physiology

    1998  Volume 436, Issue 2, Page(s) 280–288

    Abstract: The mammalian distal colon, which is composed of different cell types, actively transports Na, K and Cl in absorptive and K and Cl in secretory directions. To further characterize the K absorption process and to identify the cells involved in K ... ...

    Abstract The mammalian distal colon, which is composed of different cell types, actively transports Na, K and Cl in absorptive and K and Cl in secretory directions. To further characterize the K absorption process and to identify the cells involved in K absorption, unidirectional Rb fluxes and luminal Rb uptake into different epithelial cell types were determined in isolated guinea-pig distal colon. Net Rb absorption (1.5-2.5 micromol.h-1.cm-2) was not influenced by inhibition of Na transport with amiloride or by incubating both sides of the epithelium with Na-free solutions, but was almost completely abolished by luminal ouabain, ethoxzolamide or by incubating both sides of the epithelium with Cl-free solutions. Luminal Rb uptake, blockable by luminal ouabain, preferentially occurred in columnar surface and neck cells, to a lesser extent in surface goblet cells and to an insignificant degree in lower crypt cells. Employing a luminal Rb-Ringer (5.4 mM Rb) the Rb concentration increased within 10 min in columnar surface and neck, surface goblet and lower crypt cells to 70, 32 and about 10 mmol. kg-1 wet weight, respectively. The presence of 5.4 mM K in the luminal incubation solution reduced Rb uptake almost completely indicating a much higher acceptance of the luminal H-K-ATPase for K than for Rb. The increase in Na and decrease in K concentrations in surface and neck cells induced by luminal ouabain might indicate inhibition of the basolateral Na-K-ATPase or drastic enhancement of cellular Na uptake by the Na-H exchanger. Bilateral Na-free incubation did not alter Rb uptake, but bilateral Cl-free incubation drastically reduced it. Inhibition of net Rb absorption by ethoxzolamide and inhibition of both Rb absorption and Rb uptake by bilateral Cl-free incubation support the notion that cellular CO2 hydration is a necessary prerequisite for K absorption and that HCO3 leaves the cell via a Cl-HCO3 exchanger. Since ouabain-inhibitable transepithelial Rb flux and luminal Rb uptake rate by surface and neck cells were about the same, Rb(K) absorption seems to be accomplished mainly by columnar surface cells.
    MeSH term(s) Amiloride/pharmacology ; Animals ; Bicarbonates/metabolism ; Carbonic Anhydrase Inhibitors/pharmacology ; Chlorides/administration & dosage ; Colon/metabolism ; Enzyme Inhibitors/pharmacology ; Epithelial Cells/metabolism ; Ethoxzolamide/pharmacology ; Guinea Pigs ; Intestinal Absorption ; Male ; Ouabain/pharmacology ; Potassium/metabolism ; Potassium/pharmacology ; Rubidium/metabolism ; Sodium-Potassium-Exchanging ATPase/antagonists & inhibitors
    Chemical Substances Bicarbonates ; Carbonic Anhydrase Inhibitors ; Chlorides ; Enzyme Inhibitors ; Ouabain (5ACL011P69) ; Amiloride (7DZO8EB0Z3) ; Sodium-Potassium-Exchanging ATPase (EC 3.6.3.9) ; Rubidium (MLT4718TJW) ; Potassium (RWP5GA015D) ; Ethoxzolamide (Z52H4811WX)
    Language English
    Publishing date 1998-07
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 6380-0
    ISSN 1432-2013 ; 0031-6768
    ISSN (online) 1432-2013
    ISSN 0031-6768
    DOI 10.1007/s004240050633
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Studies of epithelial electrolyte transport by marker ions.

    Dörge, A / Rick, R

    Scanning microscopy

    1990  Volume 4, Issue 2, Page(s) 449–53; discussion 453–5

    Abstract: The paper reviews several recent studies in which marker ions, such as Rb and Br, were used to identify ion transport pathways and membrane properties in epithelia. In the frog skin epithelium, using Rb as a substitute for K, Cl transport mechanisms ... ...

    Abstract The paper reviews several recent studies in which marker ions, such as Rb and Br, were used to identify ion transport pathways and membrane properties in epithelia. In the frog skin epithelium, using Rb as a substitute for K, Cl transport mechanisms across the basolateral membranes of principal cells were studied. The data suggest that intracellular Cl is maintained above electrochemical equilibrium by an Na-K-2Cl cotransport system which, under non-stimulated conditions, is normally quiescent. In toad and frog skins, the route of transepithelial Cl movement was investigated. A subpopulation of mitochondria-rich cells demonstrated a ready exchange of Br with the apical and basal bathing media, consistent with the view that these cells constitute a transcellular anion shunt. Moreover, voltage-activation resulted in an increased Br uptake from the apical bath. Nevertheless, because of the very small number of these cells, it may be questioned whether the mitochondria-rich cell constitutes the only shuntpathway for Cl. In other studies, Rb uptake was employed to measure the Na/K-pump activity. In principal cells of the frog skin epithelium, amiloride inhibited Rb uptake and lowered Na concentration, supporting the view that this cell type is engaged in amiloride-sensitive Na transport. In contrast, no significant changes in the Rb, Na, and Cl concentration of mitochondria-rich cells were detectable. Studies with Rb as marker ion in the rabbit urinary bladder revealed that the epithelium behaves like a functional syncytium with regard to transepithelial ion transport.
    MeSH term(s) Amiloride ; Animals ; Anura ; Biological Transport, Active ; Bromides/metabolism ; Chlorides/metabolism ; Electrolytes/metabolism ; Epithelium/metabolism ; Mitochondria/physiology ; Ouabain ; Potassium/metabolism ; Rabbits ; Rubidium/metabolism ; Skin/metabolism ; Sodium/metabolism ; Urinary Bladder/metabolism
    Chemical Substances Bromides ; Chlorides ; Electrolytes ; Ouabain (5ACL011P69) ; Amiloride (7DZO8EB0Z3) ; Sodium (9NEZ333N27) ; Rubidium (MLT4718TJW) ; Potassium (RWP5GA015D)
    Language English
    Publishing date 1990-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 639040-7
    ISSN 0891-7035
    ISSN 0891-7035
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Analysis of anion conductance in frog skin.

    Nagel, W / Dörge, A

    Pflugers Archiv : European journal of physiology

    1990  Volume 416, Issue 1-2, Page(s) 53–61

    Abstract: Electrophysiological characteristics of transepithelial Cl-specific conductance (gCl) and intracellular element concentrations were analyzed in frog skins before and during voltage perturbation to serosa +100 mV, both under control conditions and after ... ...

    Abstract Electrophysiological characteristics of transepithelial Cl-specific conductance (gCl) and intracellular element concentrations were analyzed in frog skins before and during voltage perturbation to serosa +100 mV, both under control conditions and after mucosal application of procaine. Under control conditions, gCl was often minimal and almost insensitive to voltage perturbation. Procaine stimulated gCl in many cases considerably and further activation resulted then from voltage perturbation. Microelectrode determinations indicated that conductive pathways parallel to the principal cells account for the procaine-induced increase in gCl. The responses in gCl were not related to the density of mitochondria-rich (MR) cells. Electron microprobe analysis of intracellular electrolyte concentrations showed that procaine increased the Cl content of MR cells significantly. Gain of Cl was primarily due to uptake across the basolateral membrane, as indicated by the small accumulation of Br after unilateral mucosal application. Voltage perturbation to serosa +100 mV in the presence of Br on the mucosal side led in procaine-stimulated tissues to an increase of the ratio of Br/Cl content in the majority of MR cells. It was much less than predicted for conductive transcellular anion transport. Also, intracellular Cl concentrations of MR cells were far above those expected for a highly Cl-permeable basolateral membrane. The data, although indicating finite Cl/Br transport across MR cells, are incompatible with the idea that the voltage-activated conductive Cl transport occurs though these cells. Alternatively, we suggest passage across highly Cl-specific sites of a paracellular pathway.
    MeSH term(s) Animals ; Bromides/metabolism ; Chlorides/metabolism ; Electric Conductivity ; Electron Probe Microanalysis ; Kinetics ; Mitochondria/metabolism ; Procaine/pharmacology ; Rana esculenta ; Skin Physiological Phenomena
    Chemical Substances Bromides ; Chlorides ; Procaine (4Z8Y51M438)
    Language English
    Publishing date 1990-04
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 6380-0
    ISSN 1432-2013 ; 0031-6768
    ISSN (online) 1432-2013
    ISSN 0031-6768
    DOI 10.1007/bf00370221
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book ; Thesis: Rechtliche Aspekte der Wertpapierleihe

    Dörge, Andreas

    (Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81)

    1992  

    Author's details von Andreas Dörge
    Series title Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81
    Keywords Wertpapierleihe
    Language German
    Size 149 S.
    Publisher Duncker & Humblot
    Publishing place Berlin
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Univ., Diss.--Tübingen, 1991
    ISBN 3428075412 ; 9783428075416
    Database Former special subject collection: coastal and deep sea fishing

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  8. Book ; Thesis: Rechtliche Aspekte der Wertpapierleihe

    Dörge, Andreas

    (Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81)

    1992  

    Author's details von Andreas Dörge
    Series title Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81
    Keywords Wertpapierleihe ; Wertpapierrecht
    Language German
    Size 149 S.
    Publisher Duncker & Humblot
    Publishing place Berlin
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Univ., Diss.--Tübingen, 1991
    ISBN 3428075412 ; 9783428075416
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  9. Book ; Thesis: Rechtliche Aspekte der Wertpapierleihe

    Dörge, Andreas

    (Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81)

    1992  

    Author's details von Andreas Dörge
    Series title Untersuchungen über das Spar-, Giro- und Kreditwesen : Abteilung B, Rechtswissenschaft ; 81
    Keywords Repo-Geschäft ; Deutschland ; 12*21
    Language German
    Size 149 S
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Überarb. zugl.: Tübingen, Univ., Diss., 1991
    Note Literaturverz. S. 136 - 145
    ISBN 3428075412 ; 9783428075416
    Database ECONomics Information System

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  10. Article: Recovery of cell volume and electrolytes of A6 cells after re-establishing isotonicity following hypotonic stress.

    Grosse, T / Heid, I / Oztürk, I / Borgmann, S / Beck, F X / Dörge, A

    Pflugers Archiv : European journal of physiology

    2003  Volume 447, Issue 1, Page(s) 29–34

    Abstract: Cellular element concentrations and dry weight contents in A6 cells were determined using electron microprobe analysis to establish whether these cells exhibit a regulatory volume increase (post-RVD-RVI) when re-establishing isotonicity following a ... ...

    Abstract Cellular element concentrations and dry weight contents in A6 cells were determined using electron microprobe analysis to establish whether these cells exhibit a regulatory volume increase (post-RVD-RVI) when re-establishing isotonicity following a hypotonically induced regulatory volume decrease (RVD). Hypotonic stress was induced by reducing basolateral [NaCl], and hence, osmolarity fell from 260 to 140 mosmol/l. The alterations in cell volume after re-establishing isotonicity, calculated from the cellular dry weight changes, indicate within the first 2 min cell shrinkage from 120 to 76% of control, compatible with almost ideal osmometric behaviour of A6 cells, and thereafter a post-RVD-RVI to 94%. The cellular uptake of osmolytes necessary to explain the post-RVD-RVI could be accounted for solely by a gain in cellular K and Cl. The involvement of a Na-K-2Cl cotransporter in most of the KCl uptake seems plausible since basolateral bumetanide blocked KCl uptake and post-RVD-RVI. The net uptake of cations (K uptake of 185.2, Na loss of 8.2 mmol/kg dry wt) during the isotonic period exceeded the Cl uptake by 38.2 mmol/kg dry wt, suggesting the uptake of another anion and/or the alteration of cellular buffer capacity. The relatively low Na concentration maintained during the isotonic period (13.3 vs. 20.4 mmol/kg wet wt under control conditions) might favour electrolyte uptake via the Na-K-2Cl cotransporter.
    MeSH term(s) Animals ; Cell Line, Transformed ; Cell Size/drug effects ; Cell Size/physiology ; Electrolytes/analysis ; Electrolytes/metabolism ; Hypotonic Solutions/analysis ; Hypotonic Solutions/metabolism ; Isotonic Solutions/analysis ; Isotonic Solutions/metabolism ; Osmolar Concentration ; Stress, Physiological/metabolism ; Xenopus laevis
    Chemical Substances Electrolytes ; Hypotonic Solutions ; Isotonic Solutions
    Language English
    Publishing date 2003-10
    Publishing country Germany
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 6380-0
    ISSN 1432-2013 ; 0031-6768
    ISSN (online) 1432-2013
    ISSN 0031-6768
    DOI 10.1007/s00424-003-1139-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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