|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 105, 363-383, Copyright © 1995 by The Rockefeller University Press
ARTICLES |
K Anderson and G Meissner
Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill 27599-7260, USA.
In vertebrate skeletal muscle, the voltage-dependent mechanism of rapid sarcoplasmic reticulum (SR) Ca2+ release, commonly referred to as excitation-contraction (EC) coupling, is believed to be mediated by physical interaction between the transverse (T)-tubule voltage-sensing dihydropyridine receptor (DHPR) and the SR ryanodine receptor (RyR)/Ca2+ release channel. In this study, differential T-tubule and SR membrane monovalent ion permeabilities were exploited with the use of an ion-replacement protocol to study T-tubule depolarization-induced SR 45Ca2+ release from rabbit skeletal muscle whole-cell homogenates. Specificity of Ca2+ release was ascertained with the use of the DHPR antagonists D888, nifedipine and PN200-110. In the presence of the "slow" complexing Ca2+ buffer EGTA, homogenates exhibited T-tubule depolarization-induced Ca2+ release comprised of an initial rapid phase followed by a slower release phase. During the rapid phase, approximately 20% of the total sequestered Ca2+ (approximately 30 nmol 45Ca2+/mg protein), corresponding to 100% of the caffeine-sensitive Ca2+ pool, was released within 50 ms. Rapid release could be inhibited fourfold by D888. Addition to release media of the "fast" complexing Ca2+ buffer BAPTA, at concentrations > or = 4 mM, nearly abolished rapid Ca2+ release, suggesting that most was Ca2+ dependent. Addition of millimolar concentrations of either Ca2+ or Mg2+ also greatly reduced rapid Ca2+ release. These results show that T-tubule depolarization-induced SR Ca2+ release from rabbit skeletal muscle homogenates is controlled by T-tubule membrane potential- and by Ca(2+)- dependent mechanisms.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  G. Tomelleri, L. Palmucci, P. Tonin, T. Mongini, M. Marini, R. L'Erario, N. Rizzuto, and G. Vattemi SERCA1 and calsequestrin storage myopathy: a new surplus protein myopathy Brain, August 1, 2006; 129(8): 2085 - 2092. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Lopez, N. Linares, I. N. Pessah, and P. D. Allen Enhanced response to caffeine and 4-chloro-m-cresol in malignant hyperthermia-susceptible muscle is related in part to chronically elevated resting [Ca2+]i Am J Physiol Cell Physiol, March 1, 2005; 288(3): C606 - C612. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. R. Laver, E. R. O'Neill, and G. D. Lamb Luminal Ca2+-regulated Mg2+ Inhibition of Skeletal RyRs Reconstituted as Isolated Channels or Coupled Clusters J. Gen. Physiol., November 29, 2004; 124(6): 741 - 758. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Wagenknecht, C.-E. Hsieh, B. K. Rath, S. Fleischer, and M. Marko Electron Tomography of Frozen-Hydrated Isolated Triad Junctions Biophys. J., November 1, 2002; 83(5): 2491 - 2501. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Fruen, J. M. Bardy, T. M. Byrem, G. M. Strasburg, and C. F. Louis Differential Ca2+ sensitivity of skeletal and cardiac muscle ryanodine receptors in the presence of calmodulin Am J Physiol Cell Physiol, September 1, 2000; 279(3): C724 - C733. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. G. Favero Sarcoplasmic reticulum Ca2+ release and muscle fatigue J Appl Physiol, August 1, 1999; 87(2): 471 - 483. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-B. Sun, C. Caputo, and K. A. P. Edman Effects of BAPTA on force and Ca2+ transient during isometric contraction of frog muscle fibers Am J Physiol Cell Physiol, August 1, 1998; 275(2): C375 - C381. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. R. Fruen, J. R. Mickelson, and C. F. Louis Dantrolene Inhibition of Sarcoplasmic Reticulum Ca2+ Release by Direct and Specific Action at Skeletal Muscle Ryanodine Receptors J. Biol. Chem., October 24, 1997; 272(43): 26965 - 26971. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Zucchi and S. Ronca-Testoni The Sarcoplasmic Reticulum Ca2+ Channel/Ryanodine Receptor: Modulation by Endogenous Effectors, Drugs and Disease States Pharmacol. Rev., March 1, 1997; 49(1): 1 - 52. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Yano, R. El-Hayek, and N. Ikemoto Role of Calcium Feedback in Excitation-Contraction Coupling in Isolated Triads J. Biol. Chem., August 25, 1995; 270(34): 19936 - 19942. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Treves, G. Feriotto, L. Moccagatta, R. Gambari, and F. Zorzato Molecular Cloning, Expression, Functional Characterization, Chromosomal Localization, and Gene Structure of Junctate, a Novel Integral Calcium Binding Protein of Sarco(endo)plasmic Reticulum Membrane J. Biol. Chem., December 8, 2000; 275(50): 39555 - 39568. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Chawla, J. N. Skepper, and C. L.-H. Huang Differential effects of sarcoplasmic reticular Ca2+-ATPase inhibition on charge movements and calcium transients in intact amphibian skeletal muscle fibres J. Physiol., March 15, 2002; 539(3): 869 - 882. [Abstract] [Full Text] [PDF]
|
|
|
|
