scholarly journals POSSIBLE FUNCTIONING OF ACTIVE ION TRANSPORT MECHANISM IN THE MUCOUS EPITHELIAL CELLS OF NEWT STOMACH AT LOW TEMPERATURE

1977 ◽  
Vol 27 (6) ◽  
pp. 771-783
Author(s):  
Yoshinobu KANNO ◽  
Yojiro MUNEOKA ◽  
Toshiaki YAMAMI
Keyword(s):  
Epithelial Cells ◽  
Low Temperature ◽  
Ion Transport ◽  
Transport Mechanism ◽  
Active Ion Transport

Cadmium-induced Inhibition of ADH-stimulated Ion Transport in Cultured Kidney-derived Epithelial Cells (A6)

1997 ◽  
Vol 25 (3) ◽  
pp. 271-277
Author(s):  
Henning F. Bjerregaard ◽  
Brian Faurskov
Keyword(s):  
Epithelial Cells ◽  
Adenylate Cyclase ◽  
Ion Transport ◽  
Hormonal Regulation ◽  
Short Circuit ◽  
Distal Tubule ◽  
Short Circuit Current ◽  
Epithelial Cell Line ◽  
Active Ion Transport ◽  
Camp Metabolism

An epithelial cell line (A6) derived from the distal tubule of toad kidney, was used to study the effect of cadmium (Cd2+) on the increase in active ion transport induced by antidiuretic hormone (ADH). Addition of Cd2+ (1mM) to the basolateral solution of A6 epithelia generated an immediate and transient increase in active ion transport, measured as short circuit current (SCC). This increase was not affected by prior addition of ADH. However, there was a distinct inhibition of ADH-induced stimulation of SCC in epithelia pre-treated with Cd2+. Since cAMP serves as an intracellular messenger for ADH by increasing the ion permeability of the apical membrane in A6 epithelial cells, the effects of Cd2+ on enzymes involved in cAMP metabolism were measured. The results showed that Cd2+ markedly inhibits cAMP production by inhibiting adenylate cyclase (which had been stimulated with forskolin, magnesium or a non-hydrolysed GTP-analog), indicating that Cd2+ inhibits the catalytic subunit of adenylate cyclase. Furthermore, degradation of cAMP by phosphodiesterase was not stimulated by Cd2+, also suggesting that the mechanism by which Cd2+ inhibits the ADH-induced ion transport could be through inhibition of adenylate cyclase. Taken together, these results indicate that, in addition to the well-known toxic effect on the proximal tubule, Cd2+ could also have an effect on the distal part of the kidney, where the important hormonal regulation of salt and water homeostasis takes place.

scholarly journals Quantification of the ion transport mechanism in protective polymer coatings on lithium metal anodes

2021 ◽  
Author(s):  
Hongyao Zhou ◽  
Haodong Liu ◽  
Xing Xing ◽  
Zijun Wang ◽  
Sicen Yu ◽  
...  
Keyword(s):  
Ion Transport ◽  
Transport Mechanism ◽  
Polymer Coatings ◽  
Rechargeable Batteries ◽  
Cycle Life ◽  
Lithium Metal ◽  
Lithium Metal Anodes ◽  
Protective Polymer ◽  
Deposition Morphology ◽  
Metal Anodes

Protective Polymer Coatings (PPCs) protect lithium metal anodes in rechargeable batteries to stabilize the Li/electrolyte interface and to extend the cycle life by reducing parasitic reactions and improving the lithium deposition morphology.

Low temperature charge carrier hopping transport mechanism in vanadium oxide thin films grown using pulsed dc sputtering

2009 ◽  
Vol 94 (22) ◽  
pp. 222110 ◽  
Author(s):  
S. S. N. Bharadwaja ◽  
C. Venkatasubramanian ◽  
N. Fieldhouse ◽  
S. Ashok ◽  
M. W. Horn ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Charge Carrier ◽  
Vanadium Oxide ◽  
Transport Mechanism ◽  
Oxide Thin Films ◽  
Hopping Transport ◽  
Dc Sputtering ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

Basolateral Cl− uptake mechanisms in Xenopus laevis lung epithelium

2010 ◽  
Vol 299 (1) ◽  
pp. R92-R100 ◽  
Author(s):  
Jens Berger ◽  
Martin Hardt ◽  
Wolfgang G. Clauss ◽  
Martin Fronius
Keyword(s):  
Xenopus Laevis ◽  
Ion Transport ◽  
Anion Exchanger ◽  
Short Circuit ◽  
Ussing Chamber ◽  
Short Circuit Current ◽  
Transport Processes ◽  
Lung Epithelium ◽  
Active Ion Transport ◽  
Uptake Mechanisms

A thin liquid layer covers the lungs of air-breathing vertebrates. Active ion transport processes via the pulmonary epithelial cells regulate the maintenance of this layer. This study focuses on basolateral Cl− uptake mechanisms in native lungs of Xenopus laevis and the involvement of the Na+/K+/2 Cl− cotransporter (NKCC) and HCO3−/Cl− anion exchanger (AE), in particular. Western blot analysis and immunofluorescence staining revealed the expression of the NKCC protein in the Xenopus lung. Ussing chamber experiments demonstrated that the NKCC inhibitors (bumetanide and furosemide) were ineffective at blocking the cotransporter under basal conditions, as well as under pharmacologically stimulated Cl−-secreting conditions (forskolin and chlorzoxazone application). However, functional evidence for the NKCC was detected by generating a transepithelial Cl− gradient. Further, we were interested in the involvement of the HCO3−/Cl− anion exchanger to transepithelial ion transport processes. Basolateral application of DIDS, an inhibitor of the AE, resulted in a significantly decreased the short-circuit current (ISC). The effect of DIDS was diminished by acetazolamide and reduced by increased external HCO3− concentrations. Cl− secretion induced by forskolin was decreased by DIDS, but this effect was abolished in the presence of HCO3−. These experiments indicate that the AE at least partially contributes to Cl− secretion. Taken together, our data show that in Xenopus lung epithelia, the AE, rather than the NKCC, is involved in basolateral Cl− uptake, which contrasts with the common model for Cl− secretion in pulmonary epithelia.

Membrane dynamics in insect malpighian tubules

1989 ◽  
Vol 257 (5) ◽  
pp. R967-R972
Author(s):  
T. J. Bradley
Keyword(s):  
Ion Transport ◽  
Driving Force ◽  
Fluid Secretion ◽  
Membrane Dynamics ◽  
Malpighian Tubules ◽  
Membrane Insertion ◽  
Cation Pump ◽  
Active Ion Transport ◽  
Urine Formation ◽  
Apical Membranes

Urine formation in insects occurs in the Malpighian tubules by means of active ion transport and osmotically coupled water flow. The rates of urine formation can vary with time and can be modulated by diuretic hormones, developmental events, and intracellular parasitism. This paper reviews a number of recent studies in which it has been demonstrated that variations in transport rate are associated with substantial changes in tubule ultrastructure in the form of membrane insertion into and deletion from the apical microvilli. The principal driving force for fluid movement in Malpighian tubules is thought to be a common cation pump located in the apical membranes. It is proposed that modulation of the apical microvillar membrane may reflect regulation by the cells of the number of common cation pump units involved in fluid secretion.

Non-solvating, side-chain polymer electrolytes as lithium single-ion conductors: synthesis and ion transport characterization

2020 ◽  
Vol 11 (2) ◽  
pp. 461-471 ◽  
Author(s):  
Jiacheng Liu ◽  
Phillip D. Pickett ◽  
Bumjun Park ◽  
Sunil P. Upadhyay ◽  
Sara V. Orski ◽  
...  
Keyword(s):  
Ion Transport ◽  
Dielectric Relaxation ◽  
Polymer Electrolytes ◽  
Transport Mechanism ◽  
Lithium Ion ◽  
Side Chain ◽  
Chain Polymer ◽  
Single Ion Conductors ◽  
Ion Conductors

Non-solvating, side-chain polymer electrolytes with more dissociable pendent anion chemistries exhibit a dielectric relaxation dominated lithium ion transport mechanism.

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