Hypotonic cell swelling stimulates permeability to cAMP in a rat colonic cell line

Hypotonic cell swelling triggers an increase in intracellular Ca2+ concentration that is deemed responsible for the subsequent regulated volume decrease in many cells. To understand the mechanisms underlying this increase, we have studied the Ca2+ sources that contribute to hypotonic cell swelling-induced Ca2+ increase (HICI) in GH3 cells. Fura 2 fluorescence of cell populations revealed that extracellular, but not intracellular, stores of Ca2+ were required. HICI was abolished by nifedipine, a blocker of L-type Ca2+ channels, and Gd3+, a nonspecific blocker of stretch-activated channels (SACs), suggesting two components for the Ca2+ membrane pathway: L-type Ca2+ channels and SACs. Using HICI as an assay, we found that venom from the spider Grammostola spatulata could block HICI without blocking L-type Ca2+ channels. The venom did, however, block SAC activity. This suggests that Ca(2+)-permeable SACs, rather than L-type Ca2+ channels, are the sensing elements for HICI. These results support the model for volume regulation in which SACs, activated by an increase of the membrane tension during hypotonic cell swelling, trigger HICI, leading to a volume decrease.

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Functional interaction of the K-Cl cotransporter (KCC1) with the Na-K-Cl cotransporter in HEK-293 cells

AJP Cell Physiology ◽

10.1152/ajpcell.1999.276.2.c328 ◽

1999 ◽

Vol 276 (2) ◽

pp. C328-C336 ◽

Cited By ~ 89

Author(s):

Christopher M. Gillen ◽

Bliss Forbush

Keyword(s):

Cell Swelling ◽

Primary Role ◽

Functional Interaction ◽

Hek 293 ◽

Hek 293 Cells ◽

Hek Cells ◽

293 Cells ◽

Hypotonic Cell Swelling ◽

The Relationship ◽

Fold Activation

We have studied the regulation of the K-Cl cotransporter KCC1 and its functional interaction with the Na-K-Cl cotransporter. K-Cl cotransporter activity was substantially activated in HEK-293 cells overexpressing KCC1 (KCC1-HEK) by hypotonic cell swelling, 50 mM external K, and pretreatment with N-ethylmaleimide (NEM). Bumetanide inhibited 86Rb efflux in KCC1-HEK cells after cell swelling [inhibition constant ( K i) ∼190 μM] and pretreatment with NEM ( K i ∼60 μM). Thus regulation of KCC1 is consistent with properties of the red cell K-Cl cotransporter. To investigate functional interactions between K-Cl and Na-K-Cl cotransporters, we studied the relationship between Na-K-Cl cotransporter activation and intracellular Cl concentration ([Cl]i). Without stimulation, KCC1-HEK cells had greater Na-K-Cl cotransporter activity than controls. Endogenous Na-K-Cl cotransporter of KCC1-HEK cells was activated <2-fold by low-Cl hypotonic prestimulation, compared with 10-fold activation in HEK-293 cells and >20-fold activation in cells overexpressing the Na-K-Cl cotransporter (NKCC1-HEK). KCC1-HEK cells had lower resting [Cl]i than HEK-293 cells; cell volume was not different among cell lines. We found a steep relationship between [Cl]i and Na-K-Cl cotransport activity within the physiological range, supporting a primary role for [Cl]iin activation of Na-K-Cl cotransport and in apical-basolateral cross talk in ion-transporting epithelia.

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Cholesterol Depletion Facilitates Recovery from Hypotonic Cell Swelling in CHO Cells

Cellular Physiology and Biochemistry ◽

10.1159/000335856 ◽

2011 ◽

Vol 28 (6) ◽

pp. 1247-1254 ◽

Cited By ~ 4

Author(s):

Gregory B. Kowalsky ◽

Derek Beam ◽

Myung J. Oh ◽

Frederick Sachs ◽

Susan Z. Hua ◽

...

Keyword(s):

Cho Cells ◽

Cell Swelling ◽

Cholesterol Depletion ◽

Hypotonic Cell Swelling

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Small-conductance Cl? channels in HT29 cells: activation by Ca2+, hypotonic cell swelling and 8-Br-cGMP

Pflügers Archiv - European Journal of Physiology ◽

10.1007/bf00374833 ◽

1992 ◽

Vol 421 (2-3) ◽

pp. 238-246 ◽

Cited By ~ 48

Author(s):

K. Kunzelmann ◽

R. Kubitz ◽

M. Grolik ◽

R. Warth ◽

R. Greger

Keyword(s):

Cell Swelling ◽

Ht29 Cells ◽

Cl Channels ◽

Hypotonic Cell Swelling ◽

Small Conductance

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Forskolin and PMA pretreatment of HT29 cells alters their chloride conductance induced by cAMP, Ca2+ and hypotonic cell swelling

Pflügers Archiv - European Journal of Physiology ◽

10.1007/bf00374754 ◽

1994 ◽

Vol 428 (1) ◽

pp. 76-83 ◽

Cited By ~ 14

Author(s):

K. Kunzelmann ◽

N. Allert ◽

R. Kubitz ◽

W. V. Breuer ◽

Z. I. Cabantchik ◽

...

Keyword(s):

Chloride Conductance ◽

Cell Swelling ◽

Ht29 Cells ◽

Hypotonic Cell Swelling

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Cholesterol Depletion Facilitates Recovery from Hypotonic Cell Swelling of CHO

Biophysical Journal ◽

10.1016/j.bpj.2009.12.1727 ◽

2010 ◽

Vol 98 (3) ◽

pp. 318a

Author(s):

Gregory Kowalsky ◽

Derek Beam ◽

Frederick Sachs ◽

Susan Hua ◽

Irena Levitan

Keyword(s):

Cell Swelling ◽

Cholesterol Depletion ◽

Hypotonic Cell Swelling

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Preferential potentiation by hypotonic cell swelling of muscarinic cation current in guinea pig ileum

AJP Cell Physiology ◽

10.1152/ajpcell.1997.272.1.c240 ◽

1997 ◽

Vol 272 (1) ◽

pp. C240-C253 ◽

Cited By ~ 25

Author(s):

Y. Waniishi ◽

R. Inoue ◽

Y. Ito

Keyword(s):

Smooth Muscle ◽

Guinea Pig ◽

Muscarinic Receptor ◽

Time Course ◽

Cell Swelling ◽

Patch Clamp Technique ◽

Cationic Current ◽

Whole Cell Patch Clamp ◽

Voltage Dependent ◽

Hypotonic Cell Swelling

The effects of hypotonic cell swelling (HCS) on muscarinic receptor-activated cationic current in guinea pig ileal smooth muscle were investigated by the whole cell patch-clamp technique. With nystatin-perforated recording, reduced external tonicity from 312 to 262 mosM caused cell swelling but hardly affected the membrane currents activated by depolarization, such as outward-rectifying K and voltage-dependent Ca currents. In contrast, the inward current evoked by carbachol at -60 mV was greatly increased (approximately 50%) by the same extent of hypotonicity. This effect is likely to occur through potentiation of nonselective cation channels coupled to the muscarinic receptor (mNSCCs) and probably does not involve elevated intracellular Ca2+ concentration ([Ca2+]i), since neither removal of external Ca2+ nor [Ca2+]i buffering with 10 mM 1,2-bis-(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid significantly affected the results. Furthermore, the time course and degree of this potentiation closely matched those of video-microscopically monitored HCS. These results support the view that mechanosensitive modulation may be a powerful mechanism to regulate mNSCCs activity in gut smooth muscle, together with membrane potential and [Ca2+]i.

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A volume-sensitive chloride conductance in human colonic cell line T84

AJP Cell Physiology ◽

10.1152/ajpcell.1989.256.6.c1111 ◽

1989 ◽

Vol 256 (6) ◽

pp. C1111-C1119 ◽

Cited By ~ 185

Author(s):

R. T. Worrell ◽

A. G. Butt ◽

W. H. Cliff ◽

R. A. Frizzell

Keyword(s):

Cell Line ◽

Single Channel ◽

Shape Change ◽

Regulatory Volume Decrease ◽

Reversal Potential ◽

Cell Swelling ◽

Equilibrium Potential ◽

T84 Cells ◽

Pipette Solution ◽

Cl Conductance

The chloride-secreting colonic cell line, T84, was studied under whole cell patch clamp with Cl as the permeant ion in pipette and bath solutions. Transmembrane current was initially small (approximately 50 pA at +100 mV) but increased steadily to average values of 1-3 nA within 5-10 min. The development of this current was associated with visible cell swelling, either without a shape change or with membrane blebbing. Basal, preswelling current levels were restored by the addition of 50-75 mM sucrose to the bath or when pipette osmolality was reduced by an equivalent amount. These findings suggest that an isosmotic pipette filling solution behaves as if it is hypertonic by approximately 60 mosmol/kgH2O to the bath. Currents traversing the swelling-induced conductance were outwardly rectified and showed activation at hyperpolarizing voltages and inactivation at depolarizing voltages. They were Cl selective because the reversal potential for current flow approached the Cl equilibrium potential when bath [Cl] was varied. Under nonswelling conditions (bath solution, 300 mosmol/kgH2O; pipette solution, 240 mosmol/kgH2O), single-channel steps (approximately 9 pA at +100 mV) could be resolved. The single-channel characteristics were similar to the macroscopic currents recorded from swollen cells, showing inactivation at positive voltages and an outwardly rectified current-voltage relation. Summation of these single-channel events yielded currents that were similar to those from swollen cells, implying that activation of multiple channels with these properties is the basis of the swelling-induced Cl conductance. This volume-sensitive Cl conductance would contribute to a regulatory volume decrease when T84 cells swell. Its relation to the secretory Cl conductance in these cells is unknown.

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