J Physiol Society Membership
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Physiol Vol 488, Issue Pt 2 pp 267-279
Copyright © 1995 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Spencer, C I
Right arrow Articles by Berlin, J R
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Spencer, C I
Right arrow Articles by Berlin, J R

Control of sarcoplasmic reticulum calcium release during calcium loading in isolated rat ventricular myocytes.

 C I Spencer and J R Berlin

Bockus Research Institute, Graduate Hospital, Philadelphia, PA 19146, USA.

1. Isolated rat ventricular myocytes were whole-cell voltage clamped using electrodes containing fluorescent Ca2+ indicators. Cytosolic [Ca2+] ([Ca2+]i) was estimated with calcium green-2 in combination with carboxy SNARF-1 to remove movement artifacts, or with indo-1. 2. Sarcoplasmic reticulum (SR) Ca2+ was depleted using 20 mM caffeine in Na(+)-containing superfusion solution, and cells were Ca2+ loaded by voltage clamp depolarizations applied during superfusion with Na(+)-free 2 mM Ca2+ solution. Ca2+ currents (ICa) and fluorescence transients elicited by these depolarizations were measured, and the releasable Ca2+ content of the Sr was estimated from the amplitude of fluorescence transients elicited by the rapid application of 20 mM caffeine. 3. Depolarization-induced [Ca2+]i transients increased in amplitude and duration during superfusion with Na(+)-free 2 mM Ca2+ solution, independent of changes in peak ICa. Caffeine application confirmed that the SR Ca2+ content increased during this manoeuvre. 4. With increased Ca2+ loading, the fraction of releasable SR Ca2+ involved in depolarization-induced transients increased, and the gradation in [Ca2+]i transient amplitude produced by beat-to-beat variation of voltage clamp pulse duration (10-100 ms) was progressively lost. This duration dependence of [Ca2+]i transients was maintained during Ca2+ loading when the Ca2+ buffering capacity of the electrode solution was increased with 100 microM BAPTA, 150 microM EGTA, or 60 microM indo-1. 5. These data suggest that Ca2+ released from the SR during a stimulated [Ca2+]i transient promotes further SR Ca2+ release to a degree which is smoothly graded with SR Ca2+ content. The effects of exogenous Ca2+ buffers suggest that this positive feedback is mediated, at least in part, by [Ca2+]i.




This article has been cited by other articles:


Home page
 Circ. Res.Home page
E. Picht, J. DeSantiago, L. A. Blatter, and D. M. Bers
Cardiac Alternans Do Not Rely on Diastolic Sarcoplasmic Reticulum Calcium Content Fluctuations
Circ. Res., September 29, 2006; 99(7): 740 - 748.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
T. R. Shannon, F. Wang, and D. M. Bers
Regulation of Cardiac Sarcoplasmic Reticulum Ca Release by Luminal [Ca] and Altered Gating Assessed with a Mathematical Model
Biophys. J., December 1, 2005; 89(6): 4096 - 4110.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
C. I. Spencer and J. S. K. Sham
Mechanisms Underlying the Effects of the Pyrethroid Tefluthrin on Action Potential Duration in Isolated Rat Ventricular Myocytes
J. Pharmacol. Exp. Ther., October 1, 2005; 315(1): 16 - 23.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
T. R. Shannon, F. Wang, J. Puglisi, C. Weber, and D. M. Bers
A Mathematical Treatment of Integrated Ca Dynamics within the Ventricular Myocyte
Biophys. J., November 1, 2004; 87(5): 3351 - 3371.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
R. A. Bassani, J. Altamirano, J. L. Puglisi, and D. M. Bers
Action potential duration determines sarcoplasmic reticulum Ca2+ reloading in mammalian ventricular myocytes
J. Physiol., September 1, 2004; 559(2): 593 - 609.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
C. I. Spencer and J. S. K. Sham
Effects of Na+/Ca2+ exchange induced by SR Ca2+ release on action potentials and afterdepolarizations in guinea pig ventricular myocytes
Am J Physiol Heart Circ Physiol, December 1, 2003; 285(6): H2552 - H2562.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
A. Zahradnikova, M. Dura, I. Gyorke, A. L. Escobar, I. Zahradnik, and S. Gyorke
Regulation of dynamic behavior of cardiac ryanodine receptor by Mg2+ under simulated physiological conditions
Am J Physiol Cell Physiol, November 1, 2003; 285(5): C1059 - C1070.
[Abstract] [Full Text] [PDF]

Home page
 JGPHome page
H. Griffiths and K.T. MacLeod
The Voltage-sensitive Release Mechanism of Excitation Contraction Coupling in Rabbit Cardiac Muscle Is Explained by Calcium-induced Calcium Release
J. Gen. Physiol., April 28, 2003; 121(5): 353 - 373.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
W. Xiong, H. M. Moore, S. E. Howlett, and G. R. Ferrier
In Contrast to Forskolin and 3-Isobutyl-1-methylxanthine, Amrinone Stimulates the Cardiac Voltage-Sensitive Release Mechanism without Increasing Calcium-Induced Calcium Release
J. Pharmacol. Exp. Ther., September 1, 2001; 298(3): 954 - 963.
[Abstract] [Full Text]

Home page
 Circ. Res.Home page
A. W. Trafford, M. E. Diaz, and D. A. Eisner
Coordinated Control of Cell Ca2+ Loading and Triggered Release From the Sarcoplasmic Reticulum Underlies the Rapid Inotropic Response to Increased L-Type Ca2+ Current
Circ. Res., February 2, 2001; 88(2): 195 - 201.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
D. A. Eisner, H. S. Choi, M. E. Diaz, S. C. O'Neill, and A. W. Trafford
Integrative Analysis of Calcium Cycling in Cardiac Muscle
Circ. Res., December 8, 2000; 87(12): 1087 - 1094.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
A. Takahashi, P. Camacho, J. D. Lechleiter, and B. Herman
Measurement of Intracellular Calcium
Physiol Rev, October 1, 1999; 79(4): 1089 - 1125.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. A. Wasserstrom and A.-M. Vites
Activation of contraction in cat ventricular myocytes: effects of low Cd2+ concentration and temperature
Am J Physiol Heart Circ Physiol, August 1, 1999; 277(2): H488 - H498.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
M. P. Blaustein and W. J. Lederer
Sodium/Calcium Exchange: Its Physiological Implications
Physiol Rev, July 1, 1999; 79(3): 763 - 854.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
P. Tavi, C. Han, and M. Weckstrom
Mechanisms of Stretch-Induced Changes in [Ca2+]i in Rat Atrial Myocytes : Role of Increased Troponin C Affinity and Stretch-Activated Ion Channels
Circ. Res., November 30, 1998; 83(11): 1165 - 1177.
[Abstract] [Full Text] [PDF]

Home page
 Cardiovasc ResHome page
D.A Eisner, A.W Trafford, M.E Dnaz, C.L Overend, and S.C O'Neill
The control of Ca release from the cardiac sarcoplasmic reticulum: regulation versus autoregulation
Cardiovasc Res, June 1, 1998; 38(3): 589 - 604.
[Abstract] [Full Text] [PDF]

Home page
 ScienceHome page
A. M. Gómez, H. H. Valdivia, H. Cheng, M. R. Lederer, L. F. Santana, M. B. Cannell, S. A. McCune, R. A. Altschuld, and W. J. Lederer
Defective Excitation-Contraction Coupling in Experimental Cardiac Hypertrophy and Heart Failure
Science, May 2, 1997; 276(5313): 800 - 806.
[Abstract] [Full Text]

Home page
 J. Biol. Chem.Home page
T. R. Shannon, G. Chu, E. G. Kranias, and D. M. Bers
Phospholamban Decreases the Energetic Efficiency of the Sarcoplasmic Reticulum Ca Pump
J. Biol. Chem., March 2, 2001; 276(10): 7195 - 7201.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1995 The Physiological Society.