© 1997 American Heart Association, Inc.
Articles |
Enhanced Ca2+ Current and Decreased Ca2+ Efflux Restore Sarcoplasmic Reticulum Ca2+ Content After Depletion
From the Department of Veterinary Preclinical Sciences, University of Liverpool (UK).
Correspondence to Dr D.A. Eisner, Department of Veterinary Preclinical Sciences, University of Liverpool, Liverpool L69 3BX, UK. E-mail eisner{at}liv.ac.uk
Abstract [Ca2+]i was measured using the fluorescent indicator indo 1 in voltage-clamped ferret and rat ventricular myocytes. The Ca2+ content of the sarcoplasmic reticulum (SR) was estimated from the integral of the Na+-Ca2+ exchange current activated by caffeine. Refilling of the SR after caffeine removal was enhanced by stimulation. As the systolic Ca2+ transient recovered, the integral of the L-type Ca2+ current decreased and that of the Na+-Ca2+ exchange tail current increased. For the early pulses, the gain of Ca2+ via the Ca2+ current is greater than the loss via the exchanger, and during steady state stimulation, the fluxes are equal. The difference in the integrals gives a measure of the net gain of cell Ca2+ with each pulse. When these are summed, the calculated gain of cell Ca2+ agrees well with the increase of SR Ca2+ produced by stimulation, as measured from the caffeine-evoked currents. There was a nonlinear relationship between SR Ca2+ content and the magnitude of the systolic Ca2+ transient such that at high SR Ca2+ content a given increase of content had a greater effect on the Ca2+ transient than did an increase at low SR content. In conclusion, the effects of systolic Ca2+ on the Ca2+ current and Na+-Ca2+ exchange current provide a means to regulate SR Ca2+ content and thence the systolic Ca2+ transient.
Key Words: sarcoplasmic reticulum • Ca2+ • Ca2+ transient
This article has been cited by other articles:
 |
|
 |
|
  D. A. Eisner, K. M. Dibb, and A. W. Trafford The mechanism and significance of the slow changes of ventricular action potential duration following a change of heart rate Exp Physiol, May 1, 2009; 94(5): 520 - 528. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. H. Orchard, M. Pasek, and F. Brette The role of mammalian cardiac t-tubules in excitation-contraction coupling: experimental and computational approaches Exp Physiol, May 1, 2009; 94(5): 509 - 519. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H.B. Bridge and E. Savio-Galimberti What Are the Consequences of Phosphorylation and Hyperphosphorylation of Ryanodine Receptors in Normal and Failing Heart? Circ. Res., May 9, 2008; 102(9): 995 - 997. [Full Text] [PDF]
|
|
|
|
 |
|
 J. Huang, L. Hove-Madsen, and G. F. Tibbits Ontogeny of Ca2+-induced Ca2+ release in rabbit ventricular myocytes Am J Physiol Cell Physiol, February 1, 2008; 294(2): C516 - C525. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Orchard and F. Brette t-tubules and sarcoplasmic reticulum function in cardiac ventricular myocytes Cardiovasc Res, January 15, 2008; 77(2): 237 - 244. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. H. George Sarcoplasmic reticulum Ca2+ leak in heart failure: mere observation or functional relevance? Cardiovasc Res, January 15, 2008; 77(2): 302 - 314. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. M. Dibb, D. A. Eisner, and A. W. Trafford Regulation of systolic [Ca2+]i and cellular Ca2+ flux balance in rat ventricular myocytes by SR Ca2+, L-type Ca2+ current and diastolic [Ca2+]i J. Physiol., December 1, 2007; 585(2): 579 - 592. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Huang, L. Hove-Madsen, and G. F. Tibbits SR Ca2+ refilling upon depletion and SR Ca2+ uptake rates during development in rabbit ventricular myocytes Am J Physiol Cell Physiol, December 1, 2007; 293(6): C1906 - C1915. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Guo, X. Ai, T. R. Shannon, S. M. Pogwizd, and D. M. Bers Intra Sarcoplasmic Reticulum Free [Ca2+] and Buffering in Arrhythmogenic Failing Rabbit Heart Circ. Res., October 12, 2007; 101(8): 802 - 810. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Huang, C. van Breemen, K.-H. Kuo, L. Hove-Madsen, and G. F. Tibbits Store-operated Ca2+ entry modulates sarcoplasmic reticulum Ca2+ loading in neonatal rabbit cardiac ventricular myocytes Am J Physiol Cell Physiol, June 1, 2006; 290(6): C1572 - C1582. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Bito, D. Dauwe, F. Verdonck, K. Mubagwa, and K. R. Sipido The Amiodarone Derivative KB130015 [2-Methyl-3-(3,5-diiodo-4-carboxymethoxybenzyl)benzofuran] Induces an Na+-Dependent Increase of [Ca2+] in Ventricular Myocytes J. Pharmacol. Exp. Ther., January 1, 2006; 316(1): 162 - 168. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Eisner, M. E. Diaz, Y. Li, S. C. O'Neill, and A. W. Trafford Stability and instability of regulation of intracellular calcium Exp Physiol, January 1, 2005; 90(1): 3 - 12. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
M.E Diaz, H.K Graham, and A.W Trafford Enhanced sarcolemmal Ca2+ efflux reduces sarcoplasmic reticulum Ca2+ content and systolic Ca2+ in cardiac hypertrophy Cardiovasc Res, June 1, 2004; 62(3): 538 - 547. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. S. Ginsburg and D. M. Bers Modulation of excitation-contraction coupling by isoproterenol in cardiomyocytes with controlled SR Ca2+ load and Ca2+ current trigger J. Physiol., April 15, 2004; 556(2): 463 - 480. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Cordeiro, L. Greene, C. Heilmann, D. Antzelevitch, and C. Antzelevitch Transmural heterogeneity of calcium activity and mechanical function in the canine left ventricle Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1471 - H1479. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Diaz, S. C. O'Neill, and D. A. Eisner Sarcoplasmic Reticulum Calcium Content Fluctuation Is the Key to Cardiac Alternans Circ. Res., March 19, 2004; 94(5): 650 - 656. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Takamatsu, T. Nagao, H. Ichijo, and S. Adachi-Akahane L-type Ca2+ channels serve as a sensor of the SR Ca2+ for tuning the efficacy of Ca2+-induced Ca2+ release in rat ventricular myocytes J. Physiol., October 15, 2003; 552(2): 415 - 424. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J Guo and H J Duff Inactivation of ICa-L is the major determinant of use-dependent facilitation in rat cardiomyocytes J. Physiol., March 15, 2003; 547(3): 797 - 805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M Bers, W. H Barry, and S. Despa Intracellular Na+ regulation in cardiac myocytes Cardiovasc Res, March 15, 2003; 57(4): 897 - 912. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. R Sipido, P. G.A Volders, M. A Vos, and F. Verdonck Altered Na/Ca exchange activity in cardiac hypertrophy and heart failure: a new target for therapy? Cardiovasc Res, March 1, 2002; 53(4): 782 - 805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Sah, R. J Ramirez, R. Kaprielian, and P. H Backx Alterations in action potential profile enhance excitation-contraction coupling in rat cardiac myocytes J. Physiol., May 15, 2001; 533(1): 201 - 214. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
W. Meme, S C O'Neill, and D A Eisner Low sodium inotropy is accompanied by diastolic Ca2+ gain and systolic loss in isolated guinea-pig ventricular myocytes J. Physiol., February 1, 2001; 530(3): 487 - 495. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H S Choi, A W Trafford, C H Orchard, and D A Eisner The effect of acidosis on systolic Ca2+ and sarcoplasmic reticulum calcium content in isolated rat ventricular myocytes J. Physiol., December 15, 2000; 529(3): 661 - 668. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
 |
|
 D. A. Eisner and A. W. Trafford No Role for the Ryanodine Receptor in Regulating Cardiac Contraction? Physiology, October 1, 2000; 15(5): 275 - 279. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. J. Rice, M. S. Jafri, and R. L. Winslow Modeling short-term interval-force relations in cardiac muscle Am J Physiol Heart Circ Physiol, March 1, 2000; 278(3): H913 - H931. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M.E. Diaz, A.W. Trafford, S.C. O'Neill, and D.A. Eisner Can changes of ryanodine receptor expression affect cardiac contractility? Cardiovasc Res, March 1, 2000; 45(4): 1068 - 1069. [Full Text] [PDF]
|
|
|
|
|
|
A W Trafford, M E Diaz, G C Sibbring, and D A Eisner Modulation of CICR has no maintained effect on systolic Ca2+: simultaneous measurements of sarcoplasmic reticulum and sarcolemmal Ca2+ fluxes in rat ventricular myocytes J. Physiol., January 15, 2000; 522(2): 259 - 270. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-Y. Zhou, L.-S. Song, E. G Lakatta, R.-P. Xiao, and H. Cheng Constitutive {beta}2-adrenergic signalling enhances sarcoplasmic reticulum Ca2+ cycling to augment contraction in mouse heart J. Physiol., December 1, 1999; 521(2): 351 - 361. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Puglisi, W. Yuan, J. W. M. Bassani, and D. M. Bers Ca2+ Influx Through Ca2+ Channels in Rabbit Ventricular Myocytes During Action Potential Clamp : Influence of Temperature Circ. Res., September 17, 1999; 85 (6): e7 - e16. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Carmeliet Cardiac Ionic Currents and Acute Ischemia: From Channels to Arrhythmias Physiol Rev, July 1, 1999; 79(3): 917 - 1017. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. K. Sham, L.-S. Song, Y. Chen, L.-H. Deng, M. D. Stern, E. G. Lakatta, and H. Cheng Termination of Ca2+ release by a local inactivation of ryanodine receptors in cardiac myocytes PNAS, December 8, 1998; 95(25): 15096 - 15101. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
|
|
|
|
C L Overend, S C O'Neill, and D A Eisner The effect of tetracaine on stimulated contractions, sarcoplasmic reticulum Ca2+ content and membrane current in isolated rat ventricular myocytes J. Physiol., March 15, 1998; 507(3): 759 - 769. [Abstract] [Full Text] [PDF]
|
|