Chloride channels in epithelia

Gögelein, Heinz

doi:10.1016/0304-4157(88)90006-8

Cited by 203 publications

(66 citation statements)

References 128 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C1 channel described here shows many striking similarities to the outwardly rectifying anion channel found in many other epithelia (G6gelein, 1988;Tabcharani, Jensen, Riordan, and Hanrahan, 1989). These similar characteristics are an outwardly rectifying I-V relation, conductance of near 50 pS at 0 mV with symmetrical 112 mM CI solutions, at least two open and two closed states and an open probability that increases with depolarization.…”

Section: Currents"supporting

confidence: 59%

Whole-cell and single channel K+ and Cl- currents in epithelial cells of frog skin.

1991

The Journal of General Physiology

View full text Add to dashboard Cite

A B S T R A C T Whole-cell and single channel currents were studied in cells from frog (R. pipiens and R. catesbiana) skin epithelium, isolated by collagenase and trypsin treatment, and kept in primary cultures up to three days. Whole-cell currents did not exhibit any significant time-dependent kinetics under any ionic conditions used. With an external K gluconate Ringer solution the currents showed slight inward rectification with a reversal potential near zero and an average conductance of 5 nS at reversal. Ionic substitution of the external medium showed that most of the cell conductance was due to K and that very little, if any, Na conductance was present. This confirmed that most cells originate from inner epithelial layers and contain membranes with basolateral properties. At voltages more positive than 20 mV outward currents were larger with K in the medium than with Na or N-methyl-Dglucamine. Such behavior is indicative of a multi-ion transport mechanism. Wholecell K current was inhibited by external Ba and quinidine. Blockade by Ba was strongly voltage dependent, while that by quinidine was not. In the presence of high external CI, a component of outward current that was inhibited by the anion channel blocker diphenylamine-2-carboxylate (DPC) appeared in 70% of the cells. This component was strongly outwardly rectifying and reversed at a potential expected for a C1 current. At the single channel level the event most frequently observed in the cell-attached configuration was a K channel with the following characteristics: inward-rectifying I-V relation with a conductance (with 112.

show abstract

Section: Currents"supporting

confidence: 59%

Whole-cell and single channel K+ and Cl- currents in epithelial cells of frog skin.

1991

The Journal of General Physiology

View full text Add to dashboard Cite

show abstract

“…Current-voltage relationships shown in Fig. l B reveal an outward rectification, which is typical for most of the non-transmitter gated Cl-channels [6,7]. In 150 mM CsC1 solutions slope conductance ranged from 33_+ 3 pS (mean_+ S.D., n =4) at negative membrane potentials (-50 to -20 mV) to 65 _+ 2 pS at positive membrane potentials (+ 20 to + 50 mV) with a reversal potential close to 0 mV.…”

mentioning

confidence: 86%

A chloride channel in rat and human axons

Strupp¹,

Grafe²

1991

Neuroscience Letters

View full text Add to dashboard Cite

Current recordings from single chloride channels were obtained from excised and cell-attached patches of rat and human axons. In rat axons the channels showed an outwardly rectifying current-voltage relationship with a slope conductance of 33 pS at negative membrane potentials and 65 pS at positive potentials (symmetrical 150 mM CsC1). They were measurably permeable for cations (Ps,/Pcs/Pa = 0.1/0.2/1). Channel currents were independent of cytoplasmatic calcium concentration. Inactivation was not observed and gating was weakly voltage dependent. CI-channels in human axons showed similar gating behavior but had a lower conductance.Enzymatic dissociation and demyelination of myelinated axons enables single channel current recordings from the nodal and paranodal region [11]. Using this method one type of Na + channel and several types of K + channel have been described [11,12]. Another axonal conductance known from macroscopic current recordings in squid axons [10], non-myelinated rat axons [3] and myelinated rabbit axons [4] is CI-dependent. To our knowledge, single chloride channels have not been described previously in mammalian axons.A certain type of CI-channel with distinctive properties has been found in a variety of other cells, e.g. cultured hippocampal neurons [5,16], Drosophila neurons [18], crustacean axons [13] or tracheal epithelial cells [17]. This channel has an intermediate conductance (10-100 pS), is significantly permeable to cations (permeability ratio in the range of 0.1-0.35) and shows weak voltage-dependent gating. This type of channel has been designated as a 'background' CI-channel by Franciolini and Petris [6]. A C1-channel with similar electrophysiological characteristics was observed in about 5% of all gigaseal recordings from axonal patches obtained in the present study.Experiments were performed on ventral rat spinal roots and specimens of human sural nerves. Male Wistar rats (250-350 g) were anaesthetized with urethane (1.25 mg/kg, i.p.). After laminectomy 5 -10 ventral roots were removed and transferred into a culture dish. Enzymatic

show abstract

“…In order to confirm the participation of Cl -fluxes, we applied DIDS, a Cl -channel blocker [33]. After obtaining the control responses, we perfused with a hypotonic solution containing 100 μM HgCl 2 and 100 μM DIDS.…”

Section: Hg 2+ Effects On Ion Transportmentioning

confidence: 99%

Dynamic Effects of Hg2+-induced Changes in Cell Volume

Heo¹,

Meng²,

Sachs³

et al. 2008

Cell Biochem Biophys

View full text Add to dashboard Cite

Using a microfluidic volume sensor, we studied the dynamic effects of Hg 2+ on hypotonic stressinduced volume changes in CHO cells. A hypotonic challenge to control cells caused them to swell but did not evoke a significant regulatory volume decrease (RVD). Treatment with 100 μM HgCl 2 caused a substantial increase in the steady-state volume following osmotic stress. Continuous hypotonic challenge following a single 10-min exposure to HgCl 2 produced a biphasic volume increase with a steady-state volume 100% larger than control cells. Repeated hypotonic challenges to cells exposed once to Hg 2+ resulted in a sequential approach to the same steady-state volume. Stimulation after reaching steady state caused a reduction in peak cell volume. Repeated stimulation was different than continuous stimulation resulting in a more rapid approach to steady state. Substituting extracellular Na + with impermeant NMDG + in the hypotonic solution produced a rapid RVD-like volume decrease and eliminated the Hg 2+ -induced excess swelling. The volume decrease in the presence of Hg 2+ was inhibited by tetraethylammonium and 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid disodium, blockers of K + and Cl -channels, respectively, suggesting that part of the Hg 2+ effect was increasing NaCl influx over KCl efflux. The presence of multiple phases of steadystate volume and their sensitivity to the stimulation history suggests that factors beyond solute fluxes, such as modification of mechanical stress within the cytoskeleton also plays a role in the response to hypotonic stress.

show abstract

Chloride channels in epithelia

Cited by 203 publications

References 128 publications

Whole-cell and single channel K+ and Cl- currents in epithelial cells of frog skin.

Whole-cell and single channel K+ and Cl- currents in epithelial cells of frog skin.

A chloride channel in rat and human axons

Dynamic Effects of Hg2+-induced Changes in Cell Volume

Contact Info

Product

Resources

About