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Krzysztof Dolowy - One of the best experts on this subject based on the ideXlab platform.
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measurement of multi ion transport through human bronchial epithelial cell line provides an insight into the mechanism of defective water transport in cystic fibrosis
Membranes, 2020Co-Authors: Miroslaw Zajac, Andrzej Lewenstam, Piotr Bednarczyk, Krzysztof DolowyAbstract:We measured concentration changes of sodium, potassium, chloride ions, pH and the Transepithelial Potential Difference by means of ion-selective electrodes, which were placed on both sides of a human bronchial epithelial 16HBE14σ cell line grown on a porous support in the presence of ion channel blockers. We found that, in the isosmotic Transepithelial concentration gradient of either sodium or chloride ions, there is an electroneutral transport of the isosmotic solution of sodium chloride in both directions across the cell monolayer. The Transepithelial Potential Difference is below 3 mV. Potassium and pH change plays a minor role in ion transport. Based on our measurements, we hypothesize that in a healthy bronchial epithelium, there is a dynamic balance between water absorption and secretion. Water absorption is caused by the action of two exchangers, Na/H and Cl/HCO3, secreting weakly dissociated carbonic acid in exchange for well dissociated NaCl and water. The water secretion phase is triggered by an apical low volume-dependent factor opening the Cystic Fibrosis Transmembrane Regulator CFTR channel and secreting anions that are accompanied by paracellular sodium and water transport.
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new ise based apparatus for na k cl ph and Transepithelial Potential Difference real time simultaneous measurements of ion transport across epithelial cells monolayer advantages and pitfalls
Sensors, 2019Co-Authors: Miroslaw Zając, Andrzej Lewenstam, Magdalena Stobiecka, Krzysztof DolowyAbstract:Cystic Fibrosis (CF) is the most common fatal human genetic disease, which is caused by a defect in an anion channel protein (CFTR) that affects ion and water transport across the epithelium. We devised an apparatus to enable the measurement of concentration changes of sodium, potassium, chloride, pH, and Transepithelial Potential Difference by means of ion-selective electrodes that were placed on both sides of a 16HBE14σ human bronchial epithelial cell line that was grown on a porous support. Using flat miniaturized ISE electrodes allows for reducing the medium volume adjacent to cells to approximately 20 μL and detecting changes in ion concentrations that are caused by transport through the cell layer. In contrast to classic electrochemical measurements, in our experiments neither the calibration of electrodes nor the interpretation of results is simple. The calibration solutions might affect cell physiology, the medium composition might change the direction of actions of the membrane channels and transporters, and water flow that might trigger or cut off the transport pathways accompanies the transport of ions. We found that there is an electroneutral transport of sodium chloride in both directions of the cell monolayer in the isosmotic Transepithelial concentration gradient of sodium or chloride ions. The ions and water are transported as an isosmotic solution of 145 mM of NaCl.
Andrzej Lewenstam - One of the best experts on this subject based on the ideXlab platform.
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measurement of multi ion transport through human bronchial epithelial cell line provides an insight into the mechanism of defective water transport in cystic fibrosis
Membranes, 2020Co-Authors: Miroslaw Zajac, Andrzej Lewenstam, Piotr Bednarczyk, Krzysztof DolowyAbstract:We measured concentration changes of sodium, potassium, chloride ions, pH and the Transepithelial Potential Difference by means of ion-selective electrodes, which were placed on both sides of a human bronchial epithelial 16HBE14σ cell line grown on a porous support in the presence of ion channel blockers. We found that, in the isosmotic Transepithelial concentration gradient of either sodium or chloride ions, there is an electroneutral transport of the isosmotic solution of sodium chloride in both directions across the cell monolayer. The Transepithelial Potential Difference is below 3 mV. Potassium and pH change plays a minor role in ion transport. Based on our measurements, we hypothesize that in a healthy bronchial epithelium, there is a dynamic balance between water absorption and secretion. Water absorption is caused by the action of two exchangers, Na/H and Cl/HCO3, secreting weakly dissociated carbonic acid in exchange for well dissociated NaCl and water. The water secretion phase is triggered by an apical low volume-dependent factor opening the Cystic Fibrosis Transmembrane Regulator CFTR channel and secreting anions that are accompanied by paracellular sodium and water transport.
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new ise based apparatus for na k cl ph and Transepithelial Potential Difference real time simultaneous measurements of ion transport across epithelial cells monolayer advantages and pitfalls
Sensors, 2019Co-Authors: Miroslaw Zając, Andrzej Lewenstam, Magdalena Stobiecka, Krzysztof DolowyAbstract:Cystic Fibrosis (CF) is the most common fatal human genetic disease, which is caused by a defect in an anion channel protein (CFTR) that affects ion and water transport across the epithelium. We devised an apparatus to enable the measurement of concentration changes of sodium, potassium, chloride, pH, and Transepithelial Potential Difference by means of ion-selective electrodes that were placed on both sides of a 16HBE14σ human bronchial epithelial cell line that was grown on a porous support. Using flat miniaturized ISE electrodes allows for reducing the medium volume adjacent to cells to approximately 20 μL and detecting changes in ion concentrations that are caused by transport through the cell layer. In contrast to classic electrochemical measurements, in our experiments neither the calibration of electrodes nor the interpretation of results is simple. The calibration solutions might affect cell physiology, the medium composition might change the direction of actions of the membrane channels and transporters, and water flow that might trigger or cut off the transport pathways accompanies the transport of ions. We found that there is an electroneutral transport of sodium chloride in both directions of the cell monolayer in the isosmotic Transepithelial concentration gradient of sodium or chloride ions. The ions and water are transported as an isosmotic solution of 145 mM of NaCl.
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New ISE-Based Apparatus for Na+, K+, Cl−, pH and Transepithelial Potential Difference Real-Time Simultaneous Measurements of Ion Transport across Epithelial Cells Monolayer–Advantages and Pitfalls
'MDPI AG', 2019Co-Authors: Mirosław Zając, Andrzej Lewenstam, Magdalena Stobiecka, Krzysztof DołowyAbstract:Cystic Fibrosis (CF) is the most common fatal human genetic disease, which is caused by a defect in an anion channel protein (CFTR) that affects ion and water transport across the epithelium. We devised an apparatus to enable the measurement of concentration changes of sodium, potassium, chloride, pH, and Transepithelial Potential Difference by means of ion-selective electrodes that were placed on both sides of a 16HBE14σ human bronchial epithelial cell line that was grown on a porous support. Using flat miniaturized ISE electrodes allows for reducing the medium volume adjacent to cells to approximately 20 μL and detecting changes in ion concentrations that are caused by transport through the cell layer. In contrast to classic electrochemical measurements, in our experiments neither the calibration of electrodes nor the interpretation of results is simple. The calibration solutions might affect cell physiology, the medium composition might change the direction of actions of the membrane channels and transporters, and water flow that might trigger or cut off the transport pathways accompanies the transport of ions. We found that there is an electroneutral transport of sodium chloride in both directions of the cell monolayer in the isosmotic Transepithelial concentration gradient of sodium or chloride ions. The ions and water are transported as an isosmotic solution of 145 mM of NaCl
Jun Tamaoki - One of the best experts on this subject based on the ideXlab platform.
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effects of new quinolones on Transepithelial electrical Potential Difference of tracheal mucosa in vivo
Antimicrobial Agents and Chemotherapy, 2001Co-Authors: Soichiro Kanoh, Jun Tamaoki, Mitsuko Kondo, Yuko Nagano, Atsushi NagaiAbstract:Superfusion of canine tracheal mucosa with 100 μg each of grepafloxacin and ciprofloxacin per ml reduced the electrical Transepithelial Potential Difference in vivo by more than 50%. This effect was dose dependent, specific for new quinolones, and inhibited by Cl channel blockers, indicating that new quinolones attenuate Cl secretion across the airway epithelium.
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cholinergic control of rabbit tracheal Transepithelial Potential Difference in vivo
European Respiratory Journal, 1996Co-Authors: Jun Tamaoki, A Chiyotani, Etsuko Tagaya, H Takemura, Kimio KonnoAbstract:The aim of the present study was to investigate the role of the autonomic nervous system in the regulation of airway epithelial ion transport in vivo. Rabbits were anaesthetized and mechanically-ventilated through a cannula inserted above the carina. The upper tracheal mucosa was exposed, and the electrical Potential Difference (PD) between the mucosal surface and the submucosal space was continuously measured by a high-impedance voltmeter under open-circuit conditions. Perfusion of the mucosa with atropine caused a rapid decline in PD from -20.1+/-2.0 to -15.2+/-0.9 mV (p<0.01), whereas phentolamine, propranolol, or the tachykinin antagonist, FK224, had no effect. Cutting both cervical vagus nerves decreased PD to the same degree as did atropine. Exogenously applied acetylcholine increased PD in a dose-dependent manner. Topical application of ipratropium bromide reduced the baseline value PD in a dose-dependent manner. The maximal decrease in PD was 43 +/- 0.3 mV (p<0.01), and the dose required to produce a half-maximal effect was 34 microg. Perfusion with either amiloride, a Na channel blocker, and diphenylamine-2-carboxylate, a Cl channel blocker, decreased the baseline PD, and the subsequent application of ipratropium bromide further decreased the PD in each case. We conclude that a cholinergic neural component may play a role in the generation of tracheal Potential Difference in vivo, probably involving stimulation by endogenously released acetylcholine of both Cl secretion and Na absorption across the airway epithelium.
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effect of clarithromycin on Transepithelial Potential Difference in rabbit tracheal mucosa
Journal of Infection and Chemotherapy, 1995Co-Authors: Jun Tamaoki, Etsuko Tagaya, Hisashi Takemura, Kimio KonnoAbstract:Erythromycin's effectiveness in treating chronic airway diseases such as panbroncholitis may derive from its ability to inhibit chloride ion (Cl−) transport across airway mucosa, and hence to alleviate the excess sputum secretion characteristic of these disorders. To determine whether the newly developed macrolide antibiotic clarithromycin (CAM) has a similar effect, we studied its influence on the Cl− diffusion Potential Difference (Cl−PD) across rabbit tracheal mucosa using a high-impedance voltmeter under open-circuit conditions in vivo. Superfusion of the tracheal mucosal surface with 10−5 or 10−4 M CAM in the presence of the sodium-channel blocker amiloride had no effect on the Cl−PD. Intravenous administration of CAM at 10 mg/kg, however, caused a rapid decrease in Cl−PD from 10.8±0.7 to 6.9±0.4 mV (P<0.001). This effect was dose-dependent: The maximum decrease from baseline Cl−PD was 5.6±0.9 mV (P<0.001), and the dose of CAM required to produce a half-maximal effect (EC50) was 2.7 mg/kg. Intravenous erythromycin decreased Cl−PD to the same extent, whereas aminobenzyl penicillin, cefazolin and amikacin had no effect. These results suggest that CAM may inhibit Cl− secretion by airway epithelial cells in vivo, consequently decreasing water movement from the submucosa to the mucosa and perhaps inhibiting airway secretion.
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effect of histamine on airway Transepithelial Potential Difference in vivo
Ensho, 1994Co-Authors: A Chiyotani, Jun Tamaoki, Etsuko Tagaya, Satomi Takeuchi, Hisashi Takemura, Mitsuko Kondo, K KonnoAbstract:Histamine is one of the important mediators that causes a variety of allergic inflammatory responses in the airway. In the present study, to determine the effect of histamine on ion transport function across the airway mucosa, we measured Transepithelial Potential Difference (PD) of rabbit tracheal mucosa under open-circuit conditionsin vivo. A high impedance voltmeter was used to measure PD between a fluid-filled and perfused recording bridge located on the airway surface and a reference bridge in the subcutaneous space. Addition of histamine to the perfusate produced a biphasic response of PD consisting of a rapid decrease within 15 sec and the subsequent plateau, which was followed by a sustained increase after 5 min of addition. Pretreatment of tracheal mucosa with the Na channel blocker amiloride greatly inhibited the early phase reduction of PD in response to histamine, but had no effect on the late phase elevation. On the other hand, pretreatment with the Cl channel blocker diphenylamine-2-carboxylate inhibited the late phase increase of PD completely.These results indicate that early and late responses of PD are dependent on Na and Cl, respectivly, and suggest that histamine may inhibit Na absorption and stimulate Cl secretion in the airway mucosa.
M A Bailey - One of the best experts on this subject based on the ideXlab platform.
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Transepithelial electrochemical gradients in the proximal convoluted tubule during potassium depletion in the rat.
The Journal of physiology, 1998Co-Authors: D G Shirley, E J Folkerd, R J Unwin, S. J. Walter, M A BaileyAbstract:1. In order to examine the electrochemical gradient for potassium reabsorption across the S2 segment of the proximal convoluted tubule, Transepithelial Potential Differences and Transepithelial potassium concentrations were measured in anaesthetized potassium-replete and potassium-depleted rats. 2. Potassium-depleted rats were markedly hypokalaemic (plasma potassium, 1.4 +/- 0.1 vs. 4.1 +/- 0.1 mmol l-1 in potassium-replete rats) and had a significantly reduced muscle potassium content. In confirmation of previous reports, glomerular filtration rate was slightly reduced, while fractional reabsorption in the proximal convoluted tubule was enhanced. 3. In potassium-replete animals, the Transepithelial Potential Difference (PD) at the late proximal convoluted tubule was +2.1 +/- 0.3 mV (lumen positive) and the tubular fluid to plasma ultrafiltrate concentration ratio for potassium (TFK/UFK) at the same site was 1. 03 +/- 0.01. In potassium-depleted rats, there was a striking reversal of the Transepithelial PD (to -4.0 +/- 0.4 mV), while the TFK/UFK was increased to 1.19 +/- 0.03. 4. The data from both potassium-replete and potassium-depleted animals are consistent with accumulating evidence that potassium reabsorption in the proximal convoluted tubule is passive in nature and depends partly on diffusion down an electrochemical gradient.
Guy Charmantier - One of the best experts on this subject based on the ideXlab platform.
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involvement of crustacean hyperglycemic hormone in the control of gill ion transport in the crab pachygrapsus marmoratus
General and Comparative Endocrinology, 2000Co-Authors: Celine Spaningspierrot, Daniel Soyez, Francois Van Herp, Marie Gompel, Georg Skaret, Evelyse Grousset, Guy CharmantierAbstract:Total extracts of sinus glands (SG) of the euryhaline grapsid crab Pachygrapsus marmoratus contain peptidic factor(s) that stimulate osmoregulatory processes in isolated and perfused posterior gills from crabs acclimated to dilute seawater. This study investigated the nature of the active factor(s). Separation of P. marmoratus SG peptides by reverse-phase HPLC, followed by a direct enzyme-linked immunosorbent assay using an anti-Carcinus maenas crustacean hyperglycemic hormone (CHH) antiserum, identified a major immunoreactive chromatographic peak. A glucose quantification bioassay demonstrated a strong and specific hyperglycemic activity following injection of the immunoreactive peak, therefore defined as the CHH of P. marmoratus. Isolated posterior gills were then perfused with HPLC fractions using a dose of 4 SG equivalents/assay. The CHH fraction consistently and significantly increased the Transepithelial Potential Difference and Na(+) influx by about 50%. The effect was rapid and reversible. Another substance of unknown nature (eluted earlier than CHH in the HPLC gradient) caused a small increase in Na(+) influx (14%) but had no effect on the Transepithelial Potential Difference. No other peptidic product from the SG had significant effect on the measured osmoregulatory parameters. These results indicate that CHH, in addition to its hyperglycemic activity, is also implicated in the control of branchial ionic transport. This neuropeptide may thus constitute a major factor involved in the control of osmoregulation in decapod crustaceans.
