scholarly journals MDCK cells are capable of water secretion and reabsorption in response to changes in the ionic environment

2017 ◽  
Vol 95 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Janne P. Capra ◽  
Sinikka M. Eskelinen
Keyword(s):  
Water Flow ◽  
Chloride Channels ◽  
Mdck Cells ◽  
Extracellular Fluid ◽  
Chloride Ion ◽  
Chloride Secretion ◽  
Chloride Ions ◽  
Intestinal Epithelia ◽  
Fluorescent Markers ◽  
Water Secretion

A prerequisite for tissue electrolyte homeostasis is highly regulated ion and water transport through kidney or intestinal epithelia. In the present work, we monitored changes in the cell and luminal volumes of type II Madin-Darby canine kidney (MDCK) cells grown in a 3D environment in response to drugs, or to changes in the composition of the basal extracellular fluid. Using fluorescent markers and high-resolution spinning disc confocal microscopy, we could show that lack of sodium and potassium ions in the basal fluid (tetramethylammonium chloride (TMACl) buffer) induces a rapid increase in the cell and luminal volumes. This transepithelial water flow could be regulated by inhibitors and agonists of chloride channels. Hence, the driving force for the transepithelial water flow is chloride secretion, stimulated by hyperpolarization. Chloride ion depletion of the basal fluid (using sodium gluconate buffer) induces a strong reduction in the lumen size, indicating reabsorption of water from the lumen to the basal side. Lumen size also decreased following depolarization of the cell interior by rendering the membrane permeable to potassium. Hence, MDCK cells are capable of both absorption and secretion of chloride ions and water; negative potential within the lumen supports secretion, while depolarizing conditions promote reabsorption.

Shark rectal gland vasoactive intestinal peptide receptor: cloning, functional expression, and regulation of CFTR chloride channels

2006 ◽  
Vol 291 (4) ◽  
pp. R1157-R1164 ◽  
Author(s):  
Marie S. Bewley ◽  
John T. G. Pena ◽  
Florian N. Plesch ◽  
Sarah E. Decker ◽  
Gerhard J. Weber ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Chloride Channels ◽  
Functional Expression ◽  
Chloride Secretion ◽  
Chloride Conductance ◽  
Relative Potency ◽  
Rectal Gland ◽  
Intestinal Epithelia ◽  
Shark Rectal Gland ◽  
Vasoactive Intestinal Peptide Receptor

Vasoactive intestinal peptide (VIP) is a secretagogue that mediates chloride secretion in intestinal epithelia. We determined the relative potency of VIP and related peptides in the rectal gland of the elasmobranch dogfish shark and cloned and expressed the VIP receptor (sVIP-R) from this species. In the perfused rectal gland, VIP (5 nM) stimulated chloride secretion from 250 ± 66 to 2,604 ± 286 μeq·h−1·g−1; the relative potency of peptide agonists was VIP > PHI = GHRH > PACAP > secretin, where PHI is peptide histidine isoleucine amide, GHRH is growth hormone-releasing hormone, and PACAP is pituitary adenylate cylase activating peptide. The cloned sVIP-R from shark rectal gland (SRG) is only 61% identical to the human VIP-R1. It maintains a long, extracellular NH2 terminus with seven cysteine residues, and has three N-glycosylation sites and eight other residues implicated in VIP binding. Two amino acids considered important for peptide binding in mammals are not present in the shark orthologue. When sVIP-R and the CFTR chloride channel were coexpressed in Xenopus oocytes, VIP increased chloride conductance from 11.3 ± 2 to 127 ± 34 μS. The agonist affinity for activating chloride conductance by the cloned receptor was VIP > GHRH = PHI > PACAP > secretin, a profile mirroring that in the perfused gland. The receptor differs from previously cloned VIP-Rs in having a low affinity for PACAP. Expression of both sVIP-R and CFTR mRNA was detected by quantitative PCR in shark rectal gland, intestine, and brain. These studies characterize a unique G protein-coupled receptor from the shark rectal gland that is the oldest cloned VIP-R.

Flickery block of single CFTR chloride channels by intracellular anions and osmolytes

1996 ◽  
Vol 271 (2) ◽  
pp. C628-C634 ◽  
Author(s):  
P. Linsdell ◽  
J. W. Hanrahan
Keyword(s):  
Chloride Channels ◽  
Single Channel ◽  
Chinese Hamster Ovary Cells ◽  
Specific Interaction ◽  
Chinese Hamster ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Outward Rectification ◽  
Voltage Dependent

Cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation- and nucleotide-dependent chloride channel. Single CFTR currents recorded on cell show slight outward rectification, which has previously been suggested to be due to an asymmetrical chloride ion gradient or to a specific interaction between permeant intracellular anions and the channel. Using a single-channel recording from Chinese hamster ovary cells stably expressing CFTR, we have found that both the sparingly permeant anion glutamate and the impermeant anion gluconate cause a rapid, voltage-dependent block of CFTR channels when applied to the intracellular, but not the extracellular, face of excised patches. Both the affinity and the voltage dependence of block were affected by the extracellular chloride concentration in a manner consistent with chloride ions being able to repel these blocking ions from the pore. These results are discussed in terms of previous models of CFTR current outward rectification, and it is suggested that this rectification may result from a combination of asymmetrical chloride concentrations and voltage-dependent block of the channel by large cytoplasmic anions. In addition, we find that CFTR conductance is decreased by high concentrations of intracellular sucrose, sorbitol, and urea in a manner consistent with a rapid block of the channel by these molecules.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

scholarly journals Layered Double Hydroxides Precursor as Chloride Inhibitor: Synthesis, Characterization, Assessment of Chloride Adsorption Performance

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2537 ◽  
Author(s):  
Lin Chi ◽  
Zheng Wang ◽  
Youfang Zhou ◽  
Shuang Lu ◽  
Yan Yao
Keyword(s):  
Removal Rate ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Ion Removal ◽  
Hydraulic Concrete ◽  
Adsorption Behaviors ◽  
The Stability ◽  
Inhibition Performance ◽  
Double Hydroxides

In this study, the chloride adsorption behaviors of CaAl-Cl LDH precursors with various Ca:Al ratios were investigated. The optimal chloride ion removal rate was 87.06% due to the formation of hydrocalumite. The chloride adsorption products of CaAl-Cl LDH precursors were further characterized by X-ray diffraction analysis and atomic structure analysis, the adsorption mechanism was considered to be co-precipitate process. The chloride adsorption behaviors of cementitious materials blended with CaAl-Cl LDH precursors were further investigated. Leaching test according to Test Code for Hydraulic Concrete (SL352-2006) was performed to testify the stability of chloride ions in the mortar. The results show that more than 98.3% chloride ions were immobilized in cement mortar blended with CaAl-Cl LDH precursor and cannot be easily released again. The inhibition performance of steel in the electrolytes with/without CaAl LDH precursor was investigated by using electrochemical measurements. The results indicate that CaAl LDH precursor can effectively protect the passive film on steel surface by chloride adsorption. Considering the high anion exchange capacities of the LDHs, synthesized chloride adsorbent precursor can be applied as new inhibitors blended in cementitious materials to prevent the chloride-induced deterioration. Moreover, the application of chloride adsorption on CaAl-Cl LDH could also be of interest for the application of seawater blended concrete.

GABA responses in rat dentate granule neurons are mediated by chloride

1988 ◽  
Vol 66 (5) ◽  
pp. 637-642 ◽  
Author(s):  
Timothy J. Blaxter ◽  
Peter L. Carlen
Keyword(s):  
Granule Cells ◽  
Hippocampal Slices ◽  
Reversal Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Aminobutyric Acid ◽  
Granule Neurons ◽  
Nernst Equation ◽  
Central Neurons

The dendrites of granule cells in hippocampal slices responded to γ-aminobutyric acid (GABA) with a depolarization. The response was blocked by picrotoxin in a noncompetitive manner. Reductions in the extracellular chloride ion concentration changed the reversal potential of the response by an amount predicted from the Nernst equation for chloride ion. Chloride-dependent hyperpolarizing responses were sometimes also found in the cell body of the granule cells. Since the reversal potential followed that predicted from the Nernst equation for chloride, we conclude that the response was mediated by chloride ions alone with no contribution from other ions. This has not previously been shown for the depolarizing response to GABA in central neurons.

scholarly journals Faropenem Transport across the Renal Epithelial Luminal Membrane via Inorganic Phosphate Transporter Npt1

2000 ◽  
Vol 44 (3) ◽  
pp. 574-577 ◽  
Author(s):  
Hiroshi Uchino ◽  
Ikumi Tamai ◽  
Hikaru Yabuuchi ◽  
Kayoko China ◽  
Ken-ichi Miyamoto ◽  
...  
Keyword(s):  
Inorganic Phosphate ◽  
Expression System ◽  
Mevalonic Acid ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Phosphate Transporter ◽  
Disulfonic Acid ◽  
Renal Secretion ◽  
Luminal Membrane ◽  
Anionic Drugs

ABSTRACT We previously showed that the mouse inorganic phosphate transporter Npt1 operates in the hepatic sinusoidal membrane transport of anionic drugs such as benzylpenicillin and mevalonic acid. In the present study, the mechanism of renal secretion of penem antibiotics was examined by using a Xenopus oocyte expression system. Faropenem (an oral penem antibiotic) was transported via Npt1 with a Michaelis-Menten constant of 0.77 ± 0.34 mM in a sodium-independent but chloride ion-sensitive manner. When the concentration of chloride ions was increased, the transport activity of faropenem by Npt1 was decreased. Since the concentration gradient of chloride ions is in the lumen-to-intracellular direction, faropenem is expected to be transported from inside proximal tubular cells to the lumen. So, we tested the release of faropenem from Xenopusoocytes. The rate of efflux of faropenem from Npt1-expressing oocytes was about 9.5 times faster than that from control water-injectedXenopus oocytes. Faropenem transport by Npt1 was significantly inhibited by β-lactam antibiotics such as benzylpenicillin, ampicillin, cephalexin, and cefazolin to 24.9, 40.5, 54.4, and 26.2% of that for the control, respectively. Zwitterionic β-lactam antibiotics showed lesser inhibitory effects on faropenem uptake than anionic derivatives, indicating that Npt1 preferentially transports anionic compounds. Other anionic compounds, such as indomethacin and furosemide, and the anion transport inhibitor 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid significantly inhibited faropenem uptake mediated by Npt1. In conclusion, our results suggest that Npt1 participates in the renal secretion of penem antibiotics.

Osmoregulation in the Larva of the Marine Caddis Fly, Philanisus Plebeius (Walk.) (Trichoptera)

1972 ◽  
Vol 57 (3) ◽  
pp. 821-838
Author(s):  
JOHN P. LEADER
Keyword(s):  
Sodium Chloride ◽  
Osmotic Pressure ◽  
Body Surface ◽  
Sea Water ◽  
Electrical Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
The Body ◽  
Electrical Potential Difference ◽  
Caddis Fly

1. The larva of Philanisus plebeius is capable of surviving for at least 10 days in external salt concentrations from 90 mM/l sodium chloride (about 15 % sea water) to 900 mM/l sodium chloride (about 150 % sea water). 2. Over this range the osmotic pressure and the sodium and chloride ion concentrations of the haemolymph are strongly regulated. The osmotic pressure of the midgut fluid and rectal fluid is also strongly regulated. 3. The body surface of the larva is highly permeable to water and sodium ions. 4. In sea water the larva is exposed to a large osmotic flow of water outwards across the body surface. This loss is replaced by drinking the medium. 5. The rectal fluid of larvae in sea water, although hyperosmotic to the haemolymph, is hypo-osmotic to the medium, making it necessary to postulate an extra-renal site of salt excretion. 6. Measurements of electrical potential difference across the body wall of the larva suggest that in sea water this tissue actively transports sodium and chloride ions out of the body.

The chemical stability of mendipite, diaboleïte, chloroxiphite, and cumengéite, and their relationships to other secondary lead(II) minerals

1980 ◽  
Vol 43 (331) ◽  
pp. 901-904 ◽  
Author(s):  
D. Alun Humphreys ◽  
John H. Thomas ◽  
Peter A. Williams ◽  
Robert F. Symes
Keyword(s):  
Chloride Ion ◽  
Stability Diagram ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Stability Field ◽  
Cupric Ion ◽  
Free Energy Of Formation ◽  
High Concentrations ◽  
The Stability ◽  
Ph Range

SummaryThe chemical stabilities of mendipite, Pb3O2Cl2, diaboleïte, Pb2CuCl2(OH)4, chloroxiphite, Pb3CuCl2O2(OH)2, and cumengéite, Pb19Cu24Cl42 (OH)44, have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔGf°, for the four minerals are −740, −1160, −1129, and −15163±20 kJ mol−1 respectively. These values have been used to construct the stability diagram shown in fig. I which illustrates their relationships to each other and to the minerals cotunnite, PbCl2, paralaurionite, PbOHCl, and litharge, PbO. This diagram shows that mendipite occupies a large stability field and should readily form from cold, aqueous, mineralizing solutions containing variable amounts of lead and chloride ions, and over a broad pH range. The formation of paralaurionite and of cotunnite requires a considerable increase in chloride ion concentration, although paralaurionite can crystallize under much less extreme conditions than cotunnite. The encroachment of the copper minerals on to the stability fields of those mineral phases containing lead(II) only is significant even at very low relative activities of cupric ion. Chloroxiphite has a large stability field, and at given concentrations of cupric ion, diaboleïte is stable at relatively high aCl−. Cumengéite will only form at high concentrations of chloride ion.

Synthesis of Mesoporous Silica and its Adsorption Properties for Chloride Ions

2019 ◽  
Vol 956 ◽  
pp. 282-293
Author(s):  
Guo Jun Ke ◽  
Tian Shi Liu ◽  
Peng Fei Yang ◽  
Xiao Lin Tang
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Adsorption Properties ◽  
Adsorption Effect ◽  
Silica Materials ◽  
Mesoporous Silica Materials ◽  
Mcm 41

A series of mesoporous silica materials (SBA-15, MCM-41, KIT-6) with different pore structures and properties were synthesized and characterized by means of small angle X-ray scattering, transmission electron microscopy, infrared spectroscopy and nitrogen adsorption-desorption. The adsorption properties of three mesoporous silica materials for chlorine ions in aqueous solution were investigated. The results show that SBA-15, MCM-41 with two-dimensional hexagonal structure has a better adsorption effect on chloride ion than KIT-6 With cubic core structure, and MCM-41 with larger specific surface area and smaller pore size has better adsorption effect on chloride ion than on SBA-15. The specific surface area of MCM-41 is 1036 m2/g, and the The adsorption kinetics accords with the pseudo-second-order kinetic model, and the adsorption isotherm is more consistent with the Langmuir isotherm model. The optimum operating conditions for MCM-41 to adsorb chloride ions are as follows: temperature 55 °C, pH 6, adsorption time 2 h, Cl- concentration 0.01 mol/L (584 mg/L) and adsorbent concentration 1.0 g/L. Under these conditions, the adsorption capacity of MCM-41 to chloride ions is greatly enhanced, and the maximum adsorption capacity is 188.18 mg/g.

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