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Enhancement of the T-type calcium current by hyposmotic shock in isolated guinea-pig ventricular myocytes.

Published on Jul 1, 2001in Journal of Molecular and Cellular Cardiology5.05
· DOI :10.1006/jmcc.2000.1399
Caroline Pascarel6
Estimated H-index: 6
,
Fabien Brette11
Estimated H-index: 11
(University of Leeds),
Jean Yves Le Guennec3
Estimated H-index: 3
Cite
Abstract
Abstract C. Pascarel, F. Brette and J.-Y. Le Guennec. Enhancement of the T-type Calcium Current by Hyposmotic Shock in Isolated Guinea-pig Ventricular Myocytes. Journal of Molecular and Cellular Cardiology (2001) 33 , 0000–0000. It is known that swelling and shrinkage of cardiac cells can modulate their electrical activity. However, the effects of osmotic manipulation on cardiac T-type calcium current (I CaT ) has not been previously reported. In this study, we have examined the effects of cell swelling on I CaT , using the whole cell patch clamp configuration. Isolated guinea-pig ventricular myocytes were swollen by an external hypotonic challenge (0.7 T). We found that I CaT is enhanced during a hypotonic shock. This current has been determined to be the T type calcium current since it is rapidly activated and inactivated, its threshold was at negative potentials and was blocked by 40 μ m Ni 2+ . Disruption of microfilaments by cytochalasin D and of microtubules by colchicine prevented the activation of I CaT during cell swelling. Taxol had no effect. These results indicate that I CaT is increased during cell swelling and this effect needs an intact cytoskeleton.
  • References (23)
  • Citations (23)
Cite
References23
Newest
Valérie Leuranguer2
Estimated H-index: 2
(CNRS: Centre national de la recherche scientifique),
Arnaud Monteil22
Estimated H-index: 22
(CNRS: Centre national de la recherche scientifique)
+ 2 AuthorsJoël Nargeot52
Estimated H-index: 52
(CNRS: Centre national de la recherche scientifique)
T-type Ca2+ channels have been suggested to play a role in cardiac automaticity, cell growth, and cardiovascular remodeling. Although three genes encoding for a T-type Ca2+ channel have been identi...
Fabien Brette5
Estimated H-index: 5
,
Sarah Calaghan22
Estimated H-index: 22
(University of Leeds)
+ 3 AuthorsJ.-Y. Le Guennec1
Estimated H-index: 1
The effects of short (1 min) and long (7–10 min) exposure to hyposmotic solution on excitation-contraction coupling in rat ventricular myocytes were studied. After short exposure, the action potential duration at 90% repolarization (APD90), the intracellular Ca2+concentration ([Ca2+]i) transient amplitude, and contraction increased, whereas the L-type Ca2+ current (I Ca,L) amplitude decreased. Fractional sarcoplasmic reticulum (SR) Ca2+ release increased but SR Ca2+ load did not. After a long ex...
Published on Dec 1, 1999in Biophysical Journal3.67
Jung-Ha Lee9
Estimated H-index: 9
(Loyola University Medical Center),
Juan Carlos Gomora2
Estimated H-index: 2
(Loyola University Medical Center)
+ 1 AuthorsEdward Perez-Reyes57
Estimated H-index: 57
(Loyola University Medical Center)
Nickel has been proposed to be a selective blocker of low-voltage-activated, T-type calcium channels. However, studies on cloned high-voltage-activated Ca(2+) channels indicated that some subtypes, such as alpha1E, are also blocked by low micromolar concentrations of NiCl(2). There are considerable differences in the sensitivity to Ni(2+) among native T-type currents, leading to the hypothesis that there may be more than one T-type channel. We confirmed part of this hypothesis by cloning three n...
Published on Apr 1, 1998in The Journal of Physiology
Karin R. Sipido47
Estimated H-index: 47
(Katholieke Universiteit Leuven),
Edward Carmeliet41
Estimated H-index: 41
(Katholieke Universiteit Leuven),
F. Van de Werf112
Estimated H-index: 112
(Katholieke Universiteit Leuven)
1We have investigated whether Ca2+ entry through T-type Ca2+ channels participates in triggering Ca2+ release from the sarcoplasmic reticulum (SR) in single guinea-pig ventricular myocytes (whole-cell voltage clamp, K5fura-2 as [Ca2+]i indicator; all monovalent cations replaced by impermeant ions to record uncontaminated Ca2+ currents; T= 23 or 36 °C). 2T-type Ca2+ currents were elicited from a holding potential of -90 mV during steps to -50 to -20 mV. For steps to -50 mV, very small [Ca2+]i tra...
Published on Nov 17, 1997in Pflügers Archiv: European Journal of Physiology3.38
Wen Xie Xu3
Estimated H-index: 3
(SNU: Seoul National University),
Sung Joon Kim25
Estimated H-index: 25
(SNU: Seoul National University)
+ 3 AuthorsKyubo Kim39
Estimated H-index: 39
(SNU: Seoul National University)
The characteristics of volume-sensitive chloride current (ICl) induced by osmotic cell swelling were studied using the whole-cell patch-clamp technique and cell diameters of antral circular guinea-pig myocytes were simultaneously measured under isosmotic and hyposmotic conditions by using a video image analysis system. At –60 mV, osmotic cell swelling (200 mosmol/l) activated a sustained inward current. Instantaneous current/voltage (I-V) relations obtained by step voltage pulses showed an outwa...
Published on Jul 7, 1997in Pflügers Archiv: European Journal of Physiology3.38
Wen Xie Xu3
Estimated H-index: 3
(SNU: Seoul National University),
Sung Joon Kim25
Estimated H-index: 25
(SNU: Seoul National University)
+ 1 AuthorsKyubo Kim39
Estimated H-index: 39
(SNU: Seoul National University)
Using the whole-cell patch clamp technique, the role of actin microfilament in hyposmotic increase of voltage-operated calcium channel current (IBa) was studied in guinea-pig gastric myocytes. Hyposmotic superfusate (212 mOsm) increased peak IBa amplitude by 32.7 ± 6.5%; when cytochalasin-D (Cyt-D, 20 μM), an actin cytoskeleton disruptor, was used, an increase of only 9.7 ± 3.1% was seen. IBaresponse to osmotic stress was potentiated (45.1 ± 4.1% increase) by 20 μM phalloidin, an actin microfila...
W. C. Cole1
Estimated H-index: 1
,
D. Chartier1
Estimated H-index: 1
+ 1 AuthorsN. Leblanc1
Estimated H-index: 1
This study was undertaken to test the hypothesis that, in the absence of extracellular Na+, Ca2+ can permeate tetrodotoxin (TTX)-sensitive Na+ channels in Cs(+)-loaded whole cell voltage-clamped guinea pig ventricular myocytes (22-24 degrees C). With 10 mM extracellular Ca2+, 50-ms step depolarizations (-50 to +25 mV) from holding potentials of -100 or -80 mV elicited fast and slow types of inward current: 1) a small (< 400 pA) dihydropyridine-insensitive inward current that exhibited similar vo...
Published on Feb 24, 1997in Pflügers Archiv: European Journal of Physiology3.38
Ying-Ying Zhou1
Estimated H-index: 1
(Columbia University),
Jian-An Yao1
Estimated H-index: 1
(Columbia University),
Gea-Ny Tseng18
Estimated H-index: 18
(Columbia University)
We studied the effects of cell swelling on membrane currents of canine ventricular myocytes using the whole-cell patch-clamp method. Cell swelling was induced by lowering the osmolarity of the bath solution to 60% of control. Cell width and currents were measured simultaneously. Cell swelling induced little or no change in the L-type Ca, the inward rectifier, and the transient outward currents, but a marked increase in the slow delayed rectifier current (IKs) was seen. We further examined the ro...
Published on Jul 1, 1996in Cardiovascular Research7.01
Jamie I. Vandenberg36
Estimated H-index: 36
(University of Oxford),
Siân A. Rees8
Estimated H-index: 8
(University of Oxford)
+ 1 AuthorsTrevor Powell16
Estimated H-index: 16
(University of Oxford)
Published on Apr 1, 1996in Circulation Research15.86
Naoki Matsuda5
Estimated H-index: 5
,
Nobuhisa Hagiwara31
Estimated H-index: 31
+ 2 AuthorsSaichi Hosoda30
Estimated H-index: 30
Abstract Anion conductance is known to be activated by mechanical stimulation, such as osmotic cell swelling or cell inflation via the patch pipette, of canine or rabbit cardiac myocytes. The effects of mechanical stimulation on time-dependent currents, however, remain unsettled. Using the whole-cell voltage-clamp method, we have found that mechanical stimuli enhance the L-type Ca2+ current (ICa,L) in rabbit cardiac myocytes. At every membrane potential, ICa,L was reversibly increased by osmotic...
Cited By23
Newest
Caroline Cros5
Estimated H-index: 5
(University of Manchester),
Laurent Sallé11
Estimated H-index: 11
(UNICAEN: University of Caen Lower Normandy)
+ 2 AuthorsFabien Brette11
Estimated H-index: 11
(University of Manchester)
Cardiomyocyte contraction depends on rapid changes in intracellular Ca2+. In mammals, Ca2+ influx as L-type Ca2+ current (ICa) triggers the release of Ca2+ from sarcoplasmic reticulum (SR) and Ca2+-induced Ca2+ release (CICR) is critical for excitation-contraction coupling. In fish, the relative contribution of external and internal Ca2+ is unclear. Here, we characterized the role of ICa to trigger SR Ca2+ release in rainbow trout ventricular myocytes using ICa regulation by Ca2+ as an index of ...
Published on Jul 1, 2011in Pflügers Archiv: European Journal of Physiology3.38
Ed White20
Estimated H-index: 20
(University of Leeds)
Microtubules are a major component of the cardiac myocyte cytoskeleton. Interventions that alter it may influence cardiac mechanical and electrical activity by disrupting the trafficking of proteins to and from the surface membrane by molecular motors such as dynein, which use microtubules as tracks to step along. Free tubulin dimers may transfer GTP to the α-subunits of G-proteins, thus an increase in free tubulin could increase the activity of G-proteins; evidence for and against such a role e...
Published on Nov 1, 2010in Acta Pharmacologica Sinica4.01
An-tao Luo1
Estimated H-index: 1
,
Hongyan Luo7
Estimated H-index: 7
+ 4 AuthorsJürgen Hescheler1
Estimated H-index: 1
Hyposmotic challenge modulates function of L-type calcium channel in rat ventricular myocytes through protein kinase C
Published on Jun 1, 2008in Cytoskeleton2.72
György Horváth1
Estimated H-index: 1
(UAB: University of Alabama at Birmingham),
Eric J. Sorscher45
Estimated H-index: 45
(UAB: University of Alabama at Birmingham)
The coordinated, directional beating of airway cilia drives airway mucociliary clearance. Here we explore the hypothesis that airway surface liquid osmolarity is a key regulator of ciliary beating. Cilia in freshly isolated human and murine airways visualized with streaming video-microscopy exhibited a reciprocal dependence on a physiological range of luminal fluid osmolarities, across the entire range of ciliary activity (0–20 beats per sec). Increasing osmolarity slowed or completely abrogated...
Published on Jan 1, 2007in Current Topics in Membranes2.61
Catherine E. Morris6
Estimated H-index: 6
(Ottawa Hospital),
Peter F. Juranka3
Estimated H-index: 3
(Ottawa Hospital)
Publisher Summary Membrane stretch modulates the activity of voltage-gated channels (VGCs). These channels are nearly ubiquitous among eukaryotes and they are present, too, in prokaryotes, so the potential ramifications of VGC mechanosensitivity are diverse. In situ traumatic stretch can irreversibly alter VGC activity with lethal results but that is pathology. This chapter discusses the reversible responses of VGCs to stretch, with the general relation of stretch stimuli to other forms of lipid...
Published on Dec 1, 2006in Biochemical and Biophysical Research Communications2.71
Yusong He4
Estimated H-index: 4
(Tongji University),
Junjie Xiao24
Estimated H-index: 24
(Tongji University)
+ 5 AuthorsYi-Han Chen19
Estimated H-index: 19
(Tongji University)
Abstract The inward rectifier potassium channel, Kir2.1, contributes to the I K1 current in cardiac myocytes and is closely associated with atrial fibrillation. Strong evidences have shown that atrial dilatation or stretch may result in atrial fibrillation. However, the role of Kir2.1 channels in the stretch-mediated atrial fibrillation is not clear. In this study, we constructed the recombinant plasmid of KCNJ2 that encodes the Kir2.1 channel and expressed it in CHO-K1 cells. We recorded I K1 c...
Published on Oct 1, 2006in Biochimica et Biophysica Acta3.79
Sergey Missan7
Estimated H-index: 7
(Dal: Dalhousie University),
Paul Linsdell29
Estimated H-index: 29
(Dal: Dalhousie University),
Terence F. McDonald24
Estimated H-index: 24
(Dal: Dalhousie University)
Abstract Exposure of cardiac myocytes to hyposmotic solution stimulates slowly-activating delayed-rectifying K + current (I Ks ) via unknown mechanisms. In the present study, I Ks was measured in guinea-pig ventricular myocytes that were pretreated with modulators of cell signaling processes, and then exposed to hyposmotic solution. Pretreatment with compounds that (i) inhibit serine/threonine kinase activity (10–100 μM H89; 200 μM H8; 50 μM H7; 1 μM bisindolylmaleimide I; 10 μM LY294002; 50 μM ...
Published on Aug 1, 2006in Cell Calcium3.93
Guy Vassort49
Estimated H-index: 49
(French Institute of Health and Medical Research),
Karel Talavera30
Estimated H-index: 30
(Katholieke Universiteit Leuven),
Julio L. Alvarez13
Estimated H-index: 13
Abstract After the first demonstration 30 years ago that Ca 2+ could permeate through two different channels, the occurrence and role of T-type Ca 2+ current, I CaT have been the matter of hundreds of publications, including the two 1985’ reports in various cardiac tissues and species. Except for its specific biophysical characteristics, I CaT is no longer so easily distinguished from the L-type Ca 2+ current, I CaL , since it is also sensitive to multiple compounds and various neuromediators in...
Published on May 1, 2006in Progress in Biophysics & Molecular Biology2.70
Fabien Brette11
Estimated H-index: 11
(University of Leeds),
J Leroy7
Estimated H-index: 7
(UCL: University College London)
+ 1 AuthorsLaurent Sallé11
Estimated H-index: 11
(UNICAEN: University of Caen Lower Normandy)
Abstract Calcium is a ubiquitous second messenger which plays key roles in numerous physiological functions. In cardiac myocytes, Ca 2+ crosses the plasma membrane via specialized voltage-gated Ca 2+ channels which have two main functions: (i) carrying depolarizing current by allowing positively charged Ca 2+ ions to move into the cell; (ii) triggering Ca 2+ release from the sarcoplasmic reticulum. Recently, it has been suggested than Ca 2+ channels also participate in excitation–transcription c...
View next paperCell swelling has differential effects on the rapid and slow components of delayed rectifier potassium current in guinea pig cardiac myocytes.