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Yoshiki Shiba - One of the best experts on this subject based on the ideXlab platform.
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gramicidin perforated patch recording revealed the Oscillatory Nature of secretory cl movements in salivary acinar cells
The Journal of General Physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
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Gramicidin-perforated Patch Recording Revealed the Oscillatory Nature of Secretory Cl− Movements in Salivary Acinar Cells
The Journal of general physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
Makoto Sugita - One of the best experts on this subject based on the ideXlab platform.
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gramicidin perforated patch recording revealed the Oscillatory Nature of secretory cl movements in salivary acinar cells
The Journal of General Physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
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Gramicidin-perforated Patch Recording Revealed the Oscillatory Nature of Secretory Cl− Movements in Salivary Acinar Cells
The Journal of general physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
Chikara Hirono - One of the best experts on this subject based on the ideXlab platform.
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gramicidin perforated patch recording revealed the Oscillatory Nature of secretory cl movements in salivary acinar cells
The Journal of General Physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
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Gramicidin-perforated Patch Recording Revealed the Oscillatory Nature of Secretory Cl− Movements in Salivary Acinar Cells
The Journal of general physiology, 2004Co-Authors: Makoto Sugita, Chikara Hirono, Yoshiki ShibaAbstract:Elevations of cytoplasmic free calcium concentrations ([Ca2+]i) evoked by cholinergic agonists stimulate isotonic fluid secretion in salivary acinar cells. This process is driven by the apical exit of Cl− through Ca2+-activated Cl− channels, while Cl− enters the cytoplasm against its electrochemical gradient via a loop diuretic-sensitive Na+-K+-2Cl− cotransporter (NKCC) and/or parallel operations of Cl−-HCO3− and Na+-H+ exchangers, located in the basolateral membrane. To characterize the contributions of those activities to net Cl− secretion, we analyzed carbachol (CCh)-activated Cl− currents in submandibular acinar cells using the “gramicidin-perforated patch recording configuration.” Since the linear polypeptide antibiotic gramicidin creates monovalent cation-selective pores, CCh-activated Cl− currents in the gramicidin-perforated patch recording were carried by Cl− efflux via Cl− channels, dependent upon Cl− entry through Cl− transporters expressed in the acinar cells. CCh-evoked Oscillatory Cl− currents were associated with oscillations of membrane potential. Bumetanide, a loop diuretic, decreased the CCh-activated Cl− currents and hyperpolarized the membrane potential. In contrast, neither methazolamide, a carbonic anhydrase inhibitor, nor elimination of external HCO3− had significant effects, suggesting that the cotransporter rather than parallel operations of Cl−-HCO3− and Na+-H+ exchangers is the primary Cl− uptake pathway. Pharmacological manipulation of the activities of the Ca2+-activated Cl− channel and the NKCC revealed that the NKCC plays a substantial role in determining the amplitude of Oscillatory Cl− currents, while adjusting to the rate imposed by the Ca2+-activated Cl− channel, in the gramicidin-perforated patch configuration. By concerting with and being controlled by the cation steps, the Oscillatory form of secretory Cl− movements may effectively provide a driving force for fluid secretion in intact acinar cells.
S D Katore - One of the best experts on this subject based on the ideXlab platform.
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Bianchi Type II VIII and IX String Cosmological Models in F(R) Gravity
International Journal of Theoretical Physics, 2015Co-Authors: S D KatoreAbstract:In this present paper, we investigate Bianchi type II VIII and IX string cosmological models in the context of f(R) gravity. Exact solutions of the field equations are obtained. It is found that the scale factors (A,B) admit Oscillatory Nature in case of Bianchi type II and IX models. The strings do not exist in all three cosmological models for the f(R) theory of gravitation.
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Bianchi Type II VIII and IX String Cosmological Models in $F(R)$ Gravity
International Journal of Theoretical Physics, 2015Co-Authors: S D KatoreAbstract:In this present paper, we investigate Bianchi type II VIII and IX string cosmological models in the context of f(R) gravity. Exact solutions of the field equations are obtained. It is found that the scale factors (A,B) admit Oscillatory Nature in case of Bianchi type II and IX models. The strings do not exist in all three cosmological models for the f(R) theory of gravitation.
David K. Hoffman - One of the best experts on this subject based on the ideXlab platform.
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Numerical evaluation of spherical Bessel transforms via fast Fourier transforms
Journal of Computational Physics, 1992Co-Authors: Omar A. Sharafeddin, H. Ferrel Bowen, Donald J. Kouri, David K. HoffmanAbstract:The purpose of this article is to describe a new fast Fourier transform (FFT) method for calculating spherical Bessel transforms. The method is based on an expansion representation of the spherical Bessel functions in terms of sine and cosine trigonometric functions, multiplied by polynomials in inverse powers of the argument of the Bessel function [ 11. The method should be of value in algorithms in which frequent calculations of spherical Bessel transforms are required at many values of the transform variables, which is frequently the situation in time-dependent scattering calculations. The method makes use of FFTs for which the computing time for each transform scales as Nlog,(N), where N is the number of quadrature points, rather than the N2 scaling of ordinary numerical quadratures. Also, the explicit evaluation of the spherical Bessel functions is not required in the method. The method differs from that given in the work of J. D. Talman [2, 33 and A. E. Siegmon [4]. In the work of Talman [2, 33 and Siegman [4], a change to logarithmic variables is required to recast the integral transform as a convolution integral, which is then evaluated by FFT procedures. However, as pointed out by Talman, this makes the step size Ar increase proportionally with r and renders the method unsuitable for functions of an Oscillatory Nature. In particular, the Oscillatory Nature of the function is lost in the increasing mesh intervals. In essence, the Talman-Siegman method is excellent for bound state wave functions, but it is not