Impedance analysis in epithelia and the problem of gastric acid secretion

Diamond, Jared M.; Machen, Terry E.

doi:10.1007/bf01870312

Cited by 39 publications

(14 citation statements)

References 126 publications

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“…Others include, the gastric mucosa (H* secretion; Diamond & Machen, 1983 for review), turtle urinary bladder (H + secretion; Gluck, Cannon & AI-Awqati, 1982), and the toad urinary bladder (H20 absorption; Wade, Stetson & Lewis, 1981;Warncke & Lindemann, 1981;Stetson, Lewis, Alles & Wade, 1982). Colchicine has been found to inhibit the stimulation of transport for these three epithelia (Kasbekar, Obrink & Flemstrom, 1978;Arruda, Sabatini, Mola & Dytko, 1980;Taylor et al, 1973, respectively).…”

Section: Role Of the Cytoskeletonmentioning

confidence: 95%

Apical membrane area of rabbit urinary bladder increases by fusion of intracellular vesicles: An electrophysiological study

Lewis

Moura

1984

J. Membrain Biol.

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Mammalian urinary bladder undergoes, in a 24-hour period, a series of slow fillings and rapid emptying. In part the bladder epithelium accommodates volume increase by stretching the cells so as to eliminate microscopic folds. In this paper we present evidence that once the cells have achieved a smooth apical surface, further cell stretching causes an insertion of cytoplasmic vesicles resulting in an even greater apical surface area per cell and an enhanced storage capacity for the bladder. Vesicle insertion was stimulated by application of a hydrostatic pressure gradient which caused the epithelium to bow into the serosal solution. Using capacitance as a direct and nondestructive measure of area we found that stretching caused a 22% increase in area. Removal of the stretch caused area to return to within 8% of control. An alternate method for vesicle insertion was swelling the cells by reducing mucosal and serosal osmolarity. This perturbation resulted in a 74% increase in area over a 70-min period. Returning to control solutions caused area to decrease as a single exponential with an 11-min time constant. A microtubule blocking agent (colchicine) did not inhibit the capacitance increase induced by hypoosmotic solutions, but did cause an increase in capacitance in the absence of a decreased osmolarity. Microfilament disrupting agent (cytochalasin B, C.B.) inhibited any significant change in capacitance after osmotic challenge. Treatment of bladders during swelling with C.B. and subsequent return to control solutions increased the time constant of the recovery to control values (22 min). The Na+-transporting ability of the vesicles was determined and found to be greater than that of the apical membrane. Aldosterone increased the transport ability of the vesicles. We conclude that some constituent of urine causes a loss of apical membrane permeability. Using electrophysiological methods we estimated that the area of cytoplasmic vesicles is some 3.3 times that of the apical membrane area. We discuss these results in a general model for vesicle translocation in mammalian urinary bladder.

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Section: Role Of the Cytoskeletonmentioning

confidence: 95%

Apical membrane area of rabbit urinary bladder increases by fusion of intracellular vesicles: An electrophysiological study

Lewis

Moura

1984

J. Membrain Biol.

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“…11 may be relevant to other epithelia in which insertion of membrane channels by vesicles is suggested by morphological evidence, capacitance changes, or inhibition of transport by colchicine or cytochalasin B. The most spectacular example is acid secretion by gastric mucosa (Diamond & Machen, 1983). Other examples are acid secretion by turtle urinary bladder (Arruda, Sabatini, Mola & Dytko, 1980), ADH-stimulated water permeability in toad urinary bladder (Taylor, Mamelak, Reaven & Maffly, 1973;Wade, Stetson & Lewis, 1981), and intestinal secretion (Notis, Orellana & Field, 1981).…”

Section: A Proposed Turnover Cycle Of Channelsmentioning

confidence: 97%

Studies of sodium channels in rabbit urinary bladder by noise analysis

et al. 1984

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Sodium channels in rabbit urinary bladder were studied by noise analysis. There are two components of short-circuit current (Isc) and correspondingly two components of apical Na+ entry, one amiloride-sensitive (termed IA and the A channel, respectively) and one amiloride-insensitive (IL and the leak pathway, respectively). The leak pathway gives rise to l/f noise, while the A channel in the presence of amiloride gives rise to Lorentzian noise. A two-state model of the A channel accounts well for how the corner frequency and plateau value of Lorentzian noise vary with amiloride concentration. The single-channel current is 0.64 pA, and the conducting channel density is on the order of 40 copies per cell. Triamterene blocks the A channel alone, and increasing external Na+ decreases the number but not the single-channel permeability of the A channel. Hydrostatic pressure pulses ("punching") increase the number of both pathways. Repeated washing of the mucosal surface removes most of the leak pathway without affecting the A channel. Properties of the A channel revealed by noise analysis of various tight epithelia are compared, and the mechanism of l/f noise is discussed. It is suggested that the A channel is synthesized intracellularly, stored in intracellular vesicles, transferred with or from vesicular membrane into apical membrane under the action of microfilaments, and degraded into the leak pathway, which is washed out into urine or destroyed. The A channel starts with PNa/PK approximately 30 and loses selectivity in stages until PNa/PK reaches the free-solution mobility ratio (approximately 0.7) for the leak pathway. This turnover cycle functions as a mechanism of repair and regulation for Na+ channels, analogous to the repair and regulation of most intracellular proteins by turnover. Vesicular delivery of membrane channels may be operating in several other epithelia.

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“…In order to get information about the structure of the electrical circuit associated with the model membrane, which behaves in a similar manner as the gastric mucosal membrane,13 the values of 2, C,, and R , have been evaluated on the basis of an equivalent circuit model used widely for the studies of gastric mucosa and a variety of epithelia. [14][15][16][17] Electrolyte Membrane Electrolyte SCE solution solution…”

Section: Introductionmentioning

confidence: 99%

Transport studies with model membrane

Siddiqi¹,

Alvi²

1989

J Polym Sci B Polym Phys

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The most recent theory for salt concentration dependence of biionic potential, developed by Ikeda and his colleagues on the basis of thermodynamics of irreversible processes, has been compared with that of Nozaki et al. to get a relationship for the calculation of theoretical values of biionic potential. The latter are in good agreement with the experimental data gathered for the parchment‐supported manganese ferricyanide membrane in contact with various alkali chloride solutions. The conclusion of selectivity sequence of group Ia cations, reached on the basis of measurements of biionic potentials, is consistent not only with the findings of thermodynamic effective fixed charge density, evaluated by utilizing membrane potential equations provided by nonequilibrium thermodynamics, but also with the data on activation parameters calculated by making use of the theory of absolute reaction rates. The values of impedance Z, membrane resistance Rm, and membrane capacitance Cm have also been evaluated on the basis of a simple equivalent circuit model. Impedance values follow the theoretical predictions at high frequencies, but at lower frequencies there is a marked deviation from the ideal behavior probably due to roughness and nonhomogeneity of the membrane used in this investigation.

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Impedance analysis in epithelia and the problem of gastric acid secretion

Cited by 39 publications

References 126 publications

Apical membrane area of rabbit urinary bladder increases by fusion of intracellular vesicles: An electrophysiological study

Apical membrane area of rabbit urinary bladder increases by fusion of intracellular vesicles: An electrophysiological study

Studies of sodium channels in rabbit urinary bladder by noise analysis

Transport studies with model membrane

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