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  • 1
    Electronic Resource
    Electronic Resource
    Measurement of the composition of epithelial cells from the toad urinary bladder (1971)
    Springer
    The journal of membrane biology 6 (1971), S. 108-126 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Two methods are described by which epithelial cells from toad urinary bladders can be obtained for analysis of their intracellular water and electrolyte contents. In the first, a method similar to that described in 1968 by J. T. Gatzy and W. O. Berndt, sheets of epithelial cells are scraped from bladders after incubation in sodium Ringer's and collagenase (400 mg/liter). The scraped cells were incubated under various conditions and their composition subsequently determined. Oxygen consumption was also measured. In the second method, epithelial cells were scraped from hemibladders removed from chambers. These cells were then analyzed without further incubation. The morphology of epithelial cells obtained by each method is illustrated. Both methods yield similar results and evidence is provided that the derived intracellular values obtained truly reflect the composition of the epithelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01873458
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  • 2
    Electronic Resource
    Electronic Resource
    Quantitative analysis of the structural events associated with antidiuretic hormone-induced volume reabsorption in the rabbit cortical collecting tubule (1984)
    Springer
    The journal of membrane biology 79 (1984), S. 65-74 
    Details
    ISSN: 1432-1424
    Keywords: antidiuretic hormone ; rabbit cortical collecting tubule ; transepithelial volume flow ; differential interference contrast microscopy ; cell volume ; lateral intercellular spaces ; cytoplasmic vacuoles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary We quantitatively examined the influence of antidiuretic hormone (ADH)-dependent volume reabsorption on the morphology of the rabbit cortical collecting tubule. Estimates of cell volume and the geometry of the lateral intercellular spaces were extracted from differential interference contrast images of perfused nephron segments using the morphometric procedures described in the preceding paper (K.L. Kirk, D.R. DiBona and J.A. Schafer,J. Membrane Biol. 79:53–64, 1984). The results indicate that ADH addition in the presence, but not absence, of a lumen-to-bath osmotic gradient (130 to 290 mOsm) stimulated transepithelial volume flow and simultaneously increased the volumes of both the cells (+28%) and the lateral intercellular spaces (+78%). In addition, the formation of cytoplasmic vacuoles could be observed during the latter stages of the swelling response, and vacuole formation continued well after new steadystate values for transepithelial water flow and cell volume had been reached. Two main conclusions can be drawn from these results. First, the cytoplasmic vacuoles comprise a slowly filling compartment that lies in parallel to the transepithelial pathway for ADH-stimulated volume reabsorption. Second, from the magnitude of the cell volume increase, we estimate that the hydraulic conductivities of the opposing cell membranes are nearly equal during maximal ADH stimulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868527
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  • 3
    Electronic Resource
    Electronic Resource
    Direct visualization of epithelial morphology in the living amphibian urinary bladder (1978)
    Springer
    The journal of membrane biology 40 (1978), S. 45-70 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Differential interference-contrast microscopy has been applied to the study of amphibian urinary bladders,in vitro. It is demonstrated that well-resolved images can be obtained with little loss of tissue viability. Direct observations have been made on the structure of microvilli, the distribution of mitochondria in the mitochondria-rich cells, and the patency of lateral intercellular spaces. It is noted that the effective viscosity of cytoplasm is very high-that it is apparently a gel in which there is no Brownian movement of organelles. The frequency, shape, and pattern of distribution of granular and mitochondria-rich cells is determined for the commonly studied varieties ofBufo marinus. Bladders from Colombian toads contain more and larger mitochondria-rich cells than do those of the Dominican variety. There is no specific arrangement of cell-cell contacts to suggest a structural basis for cooperativeness of action. Finally, a longitudinal study of osmotically-induced changes in the structure of the “tight” or “limiting” junctions establishes the validity of previous findings by electron microscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02025998
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  • 4
    Electronic Resource
    Electronic Resource
    Extracellular Ca2+ and the effect of antidiuretic hormone on the water permeability of the toad urinary bladder: An example of flow-induced alteration of flow (1982)
    Springer
    The journal of membrane biology 67 (1982), S. 27-44 
    Details
    ISSN: 1432-1424
    Keywords: toad bladder ; antidiuretic hormone ; water permeability ; calcium ; epithelial structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The extracellular Ca2+ requirement for antidiuretic hormone (ADH) stimulation of water permeability in the toad urinary bladder has been critically examined. The polarity of the tissue was maintained with 1mm Ca2+ in the mucosal bathing medium and a serosal bath nominally free of Ca2+. Under these condition, ADH-induced osmotic water flow was inhibited by more than 60% while enhancement of the diffusional permeability to water was unaffected. Structural studies revealed that low serosal Ca2+ led to parallel alterations in epithelial architecture that amounted to a significant distorition of the osmotic water pathway. Prevention of these alterations, or restoration of normal cell-cell contact showed that the reduction of serosal Ca2+ did not restrict hormonal action,per se, but that it resulted in a weakening of cell-cell junctions such that intercellular space distension during water flow occurred to a point where the geometric conditions for maintenance of osmotic flow were compromised. We conclude that extracellular Ca2+ is not a requirement for the molecular aspects of ADH action but that, in its absence, a direct measurement of ADH-induced osmotic flow proves to be an inaccurate index of the hormone-generated changes in epithelial transport characteristics. Under certain conditions the ADH-effect on the tissue's hydraulic permeability is probably best assessed by measurement of the diffusional permability to water; although accuracy in this determination is difficult, it is not as strongly dependent on tissue geometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868645
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  • 5
    Electronic Resource
    Electronic Resource
    Clarification of the intercellular space phenomenon in toad urinary bladder (1972)
    Springer
    The journal of membrane biology 7 (1972), S. 267-274 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Vasopressin has been noted to increase the size of the intercellular spaces of toad bladder epithelium even in the absence of an osmotic gradient. The present studies demonstrate that the same phenomenon may be obtained in the presence or absence of a transepithelial gradient of glutaraldehyde indicating that the effect is not a fixation artifact. Morphologic evidence is presented demonstrating continuity between the epithelium and underlying smooth muscle. The data support the concept that not only net water flow, but also changes in smooth muscle tone can appreciably affect the epithelial geometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867919
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  • 6
    Electronic Resource
    Electronic Resource
    The cellular specificity of the effect of vasopressin on toad urinary bladder (1969)
    Springer
    The journal of membrane biology 1 (1969), S. 79-91 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Phase and electron micrographs of toad bladders were obtained following dilution of bathing media in the presence and absence of vasopressin. Dilution of the mucosal medium alone resulted in no morphologic changes. Subsequent addition of vasopressin produced an increase in the cell volume of the granular cells, manifested by some or all of the following changes: increased area of granular cell profiles as observed in sections, rounding of the cell nucleus, displacement of the two components of the nuclear envelope, loss of nuclear heterochromatin, sacculation of the endoplasmic reticulum and the Golgi apparatus, and reduction in the electron density of the cell cytoplasm. No such morphologic changes were noted in the other cell types comprising the mucosal epithelium — the mitochondria-rich, the goblet, and the basal cells. On the other hand, dilution of the serosal bathing medium in the absence of vasopressin caused a marked increase in the cell volume of all these cell types. The results demonstrate that the action of vasopressin to enhance bulk water flow across toad bladder is exerted specifically on the apical surface of the granular cells. It is suggested that the hormonal effect on sodium transport may also be limited to the granular cells. The route of osmotic water flow and the possible role of the other mucosal epithelial cells is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869775
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  • 7
    Electronic Resource
    Electronic Resource
    Cell volume regulation and ischemic tissue damage (1972)
    Springer
    The journal of membrane biology 10 (1972), S. 331-343 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Over years of friendly meetings with Professor Aharon Katzir-Katchalsky, many topics of mutual interest were discussed. He was the ideal person to come to with a problem. After being subjected to his critical, analytic mind, most research problems seemed simple, more clearly defined and understandable. His broad biologic and scientific background grew from an apparently insatiable interest in all natural phenomena. He generously shared his knowledge and imparted his wisdom with a share of his own infectious excitement. He was quick to sense the significance of understanding of biological processes to their practical application. For this reason it seems appropriate to relate the progress made in the understanding of cell volume regulation, which had been discussed on several occasions with him, to its possible significance as a factor in disease processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867864
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  • 8
    Electronic Resource
    Electronic Resource
    Pathways for movement of ions and water across toad urinary bladder (1974)
    Springer
    The journal of membrane biology 19 (1974), S. 195-220 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Application of either mucosal hypertonicity or serosal hypotonicity increases the electrical conductance of toad urinary bladder by altering the permeability of the apical intercellular junctions which are rate-limiting to transepithelial flow of ions and water between the cells. Prior addition of vasopressin has been found to inhibit both the electrical and morphologic effects. In the presence of mucosal hypertonicity, the hormone also induces shrinkage of the granular cells, with no perceptible change in the volume of the other epithelial cells. The skin ofXenopus laevis is similarly responsive to increases in tonicity of the outer bathing medium but here, where vasopressin exerts a natriferic but not a hydroosmotic effect, hormone administration does not inhibit the osmotically induced electrical and morphologic changes. These results may be interpreted within the framework of current concepts concerning the granular cell response to vasopressin and the response of the limiting junctions to transepithelial osmotic gradients. Vasopressin facilitates hydroosmotic flow in either direction across the epithelium, specifically by increasing the water permeability of the luminal-facing plasma membrane of the granular cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869978
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  • 9
    Electronic Resource
    Electronic Resource
    Pathways for movement of ions and water across toad urinary bladder (1978)
    Springer
    The journal of membrane biology 38 (1978), S. 359-386 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Hypertonicity of the mucosal bathing medium increases the electrical conductance of toad urinary bladder by osmotic distension of the epithelial “tight” or limiting junctions. However, toad urine is not normally hypertonic to plasma. In this study, the transmural osmotic gradient was varied strictly within the physiologic range; initially hypotonic mucosal bathing media were made isotonic by addition of a variety of solutes. Mucosal NaCl increased tissue conductance substantially. This phenomenon could not have reflected solely an altered conductance of the transcellular active transport pathway since mucosal KCl also increased tissue conductance, whether or not Na+ was present in the bathing media. The effect of mucosal NaCl could not have been mediated solely by a parallel transepithelial pathway formed by damaged tissue since mucosal addition of certain nonelectrolytes also increased tissue conductance. Finally, the osmotically-induced increase in conductance could not have occurred solely in transcellular transepithelial channels in parallel with the active pathway for Na+, since the permeability to22Na from serosa to mucosa (s tom) was also increased by mucosal addition of NaCl; a number of lines of evidence suggest thats-to-m movement of Na+ proceeds largely through paracellular transepithelial pathways. The results thus establish that the permeability of the limiting junctions is physiologically dependent on the magnitude of the transmural osmotic gradient. A major role is proposed for this mechanism, serving to conserve the body stores of NaCl from excessive urinary excretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01870152
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  • 10
    Electronic Resource
    Electronic Resource
    Intracellular solute gradients during osmotic water flow: An electron-microprobe analysis (1987)
    Springer
    The journal of membrane biology 96 (1987), S. 85-94 
    Details
    ISSN: 1432-1424
    Keywords: ADH ; osmotic water flow ; transepithelial Na transport ; toad urinary bladder epithelium ; X-ray microanalysis ; intracellular ion concentrations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In an attempt to quantify possible intracellular water activity gradients during ADH-induced osmotic water flow, we employed energy dispersive X-ray microanalysis to thin, freezedried cryosections obtained from fresh, shock-frozen tissue of the toad urinary bladder. The sum of all detectable small ions (Na + K + Cl) in the cellular water space was taken as an index of the intracellular osmolarity. Presuming that all ions are osmotically active, they comprise about 90% of the cellular solutes. When the cells were exposed to dilute serosal medium, the reduction in the sum of the ions agreed well with the expected reduction in osmolarity. After inducing water flow by addition of ADH and dilution of the mucosal medium, all epithelial cells showed a fall in osmolarity. The change was more pronounced in granular cells than in basal or mitochondria-rich cells, consistent with the notion that granular cells represent the main transport pathway. Most significantly, intracellular osmolarity gradients, largely caused by an uneven distribution of K and Na, were detectable in granular cells. The gradients were not observed after ADH or mucosal dilution alone, or when the direction of transepithelial water flow was reversed. We conclude from these results that there is a significant cytoplasmic resistance to water flow which may lead to intracellular gradients of water activity. Concentration gradients of diffusible cations can be explained by a flow-induced Donnan-type distribution of fixed negative charges. With regard to transepithelial Na transport, the data suggest that ADH stimulates transport by increasing the Na permeability of the apical membranes of granular cells specifically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869337
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