Activation by hyperpolarization and atypical osmosensitivity of a Cl? current in rat osteoblastic cells

Chesnoy-Marchais, Dominique; Fritsch, Janine

doi:10.1007/bf00233706

Cited by 32 publications

(33 citation statements)

References 56 publications

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“…An additional difference is that 9AC appeared to have a much slower onset of action than the other two compounds. A similar voltage-dependent effect of DIDS was observed for the hyperpolarization-activated chloride current in rat osteoblastic cells (Chesnoy-Marchais & Fritsch, 1994). We have found that DIDS is also an effective blocker of ClC_2 channels expressed in Xenopus oocytes.…”

Section: Discussionsupporting

confidence: 80%

“…This current is not carried by cations since it was unaffected by agents which block hyperpolarization-activated cation currents such as IQ (Halliwell & Adams, 1982;Lamas et al 1997) or inwardly rectifying potassium currents (see Hille, 1992). Many of the properties of ICl,IR are, however, similar to other hyperpolarizationactivated chloride currents such as those that have been recorded in rat osteoblastic cells (Chesnoy-Marchais & Fritsch, 1994), T84 epithelial cells (Fritsch & Edelman, 1996) and Aplysia neurons (Chesnoy-Marchais, 1983). The threshold for activation of ICl,IR is within the range observed for the other currents and all of these currents exhibit inward rectification.…”

Section: Discussionmentioning

confidence: 52%

“…Such currents are activated rapidly by depolarization, display outward rectification, have a halide selectivity sequence of I¦ > Br¦ > Cl¦ and require ATP (Anderson, Sheppard, Berger & Welsh, 1992;Ackerman, Wickman & Clapham, 1994;Nilius et al 1994;Arreola et al 1995Arreola et al , 1996. A number of currents which share common features with ICl,IR, such as the hyperpolarization-activated chloride currents of rat osteoblastic cells (Chesnoy-Marchais & Fritsch, 1994), mandibular duct cells (Komwatana, Dinudom, Young & Cook, 1995), T84 cells (Fritsch & Edelman, 1997) and the ClC_2-induced chloride current do exhibit sensitivity to changes in the external osmolarity. However, in rat osteoblastic cells and mandibular duct cells, the effects of a hyposmotic solution are opposite to those demonstrated for ICl,IR in that the currents in these cells are reduced under hyposmotic conditions.…”

Section: Discussionmentioning

confidence: 99%

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Characterization of the hyperpolarization‐activated chloride current in dissociated rat sympathetic neurons

Clark

Jordt

Jentsch

et al. 1998

The Journal of Physiology

106

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Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization‐activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N‐methyl‐D‐glucamine) or by addition of 10 mM caesium or barium ions. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl− > Br− > I− > cyclamate. All substituted permeant anions also blocked the current. The current was blocked by DIDS (4,4′‐diisothiocyanatostilbene‐2,2′‐disulphonic acid), 9AC (anthracene‐9‐carboxylic acid) and NPPB (5‐nitro‐2‐(3‐phenylpropylamino)benzoic acid) but was unaffected by SITS (4‐acetamido‐4′‐isothiocyanatostilbene‐2,2′‐disulphonic acid) and niflumic acid. The effective blockers were voltage dependent; DIDS and NPPB were more effective at depolarized potentials while 9AC was more effective at hyperpolarized potentials. The current was enhanced by extracellular acidification and reduced by extracellular alkalinization. Reducing external osmolarity was without effect in conventional whole‐cell recording but enhanced current amplitude in those perforated‐patch recordings where little current was evident in control external solution. The current in SCG neurons was blocked by external cadmium and zinc. ClC‐2 chloride currents expressed in Xenopus oocytes were also sensitive to block by these divalent ions and by DIDS but the sensitivity of ClC‐2 to block by cadmium ions was lower than that of the current in SCG neurons. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) experiments showed the presence of mRNA for ClC‐2 in SCG neurons but not in rat cerebellar granule cells which do not possess a hyperpolarization‐activated Cl− current. The data suggest that ClC‐2 may be functionally expressed in rat SCG neurons. This current may play a role in regulating the internal chloride concentration in these neurons and hence their response to activation of GABAA receptors.1. Dissociated rat superior cervical ganglion (SCG) neurons have been shown to possess a hyperpolarization‐activated inwardly rectifying chloride current. The current was not altered by changes in external potassium concentration, replacing external cations with NMDG (N‐methyl‐D‐glucamine) or by addition of 10 mM caesium or barium ions. The reversal potential of the current was altered by changing external anions. The anion selectivity of the current was Cl− > Br− > I− > cyclamate. All substituted permeant anions also blocked the current.

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Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 99%

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Characterization of the hyperpolarization‐activated chloride current in dissociated rat sympathetic neurons

Clark

Jordt

Jentsch

et al. 1998

The Journal of Physiology

106

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“…This increase in Na+/K+/2ClI cotransporter activity produces an increase in the Cl-content (Martinez et al, 1988), which gives rise to an increase in cell volume (Foskett, 1990). Native and expressed CIC-2 Cl-channels can apparently sense the internal Cl-concentration (Dinudom et al, 1993;Chesnoy-Marchais and Fritsch, 1994;Fritsch and Edelman, 1997) and the cell volume (GrOnder et al, 1992;Thiemann et al, 1992;Jordt and Jentsch, 1997). Channel activity increases as the Cl-concentration and the cell volume increase.…”

Section: Sympathetic 1-adrenergic Stimulationmentioning

confidence: 99%

Chloride Channels and Salivary Gland Function

Melvin

1999

Critical Reviews in Oral Biology & Medicine

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Fluid and electrolyte transport is driven by transepithelial Cl movement. The opening of Cl-channels in the apical membrane of salivary gland acinar cells initiates the fluid secretion process, whereas the activation of Cl-channels in both the apical and the basolateral membranes of ductal cells is thought to be necessary for NaCl re-absorption. Saliva formation can be evoked by sympathetic and parasympathetic stimulation. The composition and flow rate vary greatly, depending on the type of stimulation. As many as five classes of Cl channels with distinct gating mechanisms have been identified in salivary cells. One of these Cl-channels is activated by intracellular Ca2 , while another is gated by cAMP An increase in the intracel lular free Ca2+ concentration is the dominant mechanism triggering fluid secretion from acinar cells, while cAMP may be required for efficient NaCl re-absorption in many ductal cells. In addition to cAMP-and Ca2+-gated Cl-channels, agonistinduced changes in membrane potential and cell volume activate different Cl-channels that likely play a role in modulating fluid and electrolyte movement. In this review, the properties of the different types of Cl-currents expressed in salivary gland cells are described, and functions are proposed based on the unique properties of these channels.

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“…To our knowledge, there are only few examples of native Cl − channels activated by external protons. The best studied pH-sensitive Cl − current is the inwardly rectifying Cl − channel ClC-2 for which numerous studies on both native and cloned channels indicated an extreme sensitivity to extracellular protons and an inhibition by Cd 2+ [30][31][32][33][34]. A recent study characterized an endogenous Cl − current in transformed human embryonic kidney HEK-293 cells, activated by extracellular pH [35].…”

Section: Discussionmentioning

confidence: 99%

Pharmacological profile of inhibition of the chloride channels activated by extracellular acid in cultured rat Sertoli cells

et al. 2006

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-Sertoli cells from mammalian testis are key cells involved in the development and maintenance of stem cell spermatogonia as well as in the secretion of a Cl − and K + -rich fluid into the lumen of seminiferous tubules. The pharmacology and contribution of Cl − channels to the physiology of Sertoli cells were investigated using whole-cell patch clamp and iodide efflux experiments applied to cultured rat Sertoli cells. We characterized an outwardly rectifying Cl − current stimulated by various acid species including the physiologically relevant lactic acid. Using the iodide efflux technique, the pharmacological properties of this Cl − current, noted ICl acid , revealed Ca 2+ -independent inhibition by DIDS (IC 50 = 27 µM), glibenclamide (IC 50 = 31 µM) and DPC (IC 50 = 86 µM). ICl acid was neither affected by calix[4]arene nor by 9-AC. The order of potency for inhibition of ICl acid is DIDS ≈ glibenclamide > DPC >> calix[4]arene, 9-AC. For comparison, the inhibitory profile of the swelling-and ATP-activated Cl − currents in Sertoli cells is DPC = DIDS >> glibenclamide = 9-AC for ICl swell and DPC = 9-AC = DIDS >> glibenclamide for ICl ATP . This description provides new insights into the physiology and pharmacology of the endogenous Cl − channels expressed and potentially involved in fluid secretion in Sertoli cells.Cl − channels / pharmacology / proton-activation / ATP / cell volume / glibenclamide

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Activation by hyperpolarization and atypical osmosensitivity of a Cl? current in rat osteoblastic cells

Cited by 32 publications

References 56 publications

Characterization of the hyperpolarization‐activated chloride current in dissociated rat sympathetic neurons

Characterization of the hyperpolarization‐activated chloride current in dissociated rat sympathetic neurons

Chloride Channels and Salivary Gland Function

Pharmacological profile of inhibition of the chloride channels activated by extracellular acid in cultured rat Sertoli cells

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