AJP - Cell Physiology, Vol 254, Issue 3 C459-C465, Copyright © 1988 by American Physiological Society

ARTICLES

Ca2+ release from sarcoplasmic reticulum of skinned fast- and slow-twitch muscle fibers

G. Salviati and P. Volpe
Istituto di Patologia Generale, Universita di Padova, Italy.

We have performed a comparative study of Ca2+ release from the sarcoplasmic reticulum (SR) of chemically skinned fibers from rabbit fast- and slow-twitch skeletal muscle. Ca2+ fluxes have been indirectly monitored by following either tension development or the inhibition of net Ca2+-loading rate by a light-scattering method. Several drugs (Ca2+-release modulators) have been used to either trigger or block Ca2+ release. Our results indicate that caffeine, doxorubicin, and ryanodine activate Ca2+ release, whereas ruthenium red blocks Ca2+ release from both fast- and slow-twitch skinned fibers. Caffeine has greater affinity for slow SR, whereas doxorubicin, ruthenium red, and ryanodine have greater affinity for fast SR. Our results indicate that Ca2+-release mechanisms in fast and slow SR are homologous but not identical and that differences in twitch-contraction time might be also related to the inherent properties of the Ca2+-release mechanism.

This article has been cited by other articles:

				A. Esposito, E. Germinario, M. Zanin, P. T. Palade, R. Betto, and D. Danieli-Betto Isoform switching in myofibrillar and excitation-contraction coupling proteins contributes to diminished contractile function in regenerating rat soleus muscle J Appl Physiol, April 1, 2007; 102(4): 1640 - 1648. [Abstract] [Full Text] [PDF]

				R. Rossi, R. Bottinelli, V. Sorrentino, and C. Reggiani Response to caffeine and ryanodine receptor isoforms in mouse skeletal muscles Am J Physiol Cell Physiol, August 1, 2001; 281(2): C585 - C594. [Abstract] [Full Text] [PDF]

				J. Morrissette, L. Xu, A. Nelson, G. Meissner, and B. A. Block Characterization of RyR1-slow, a ryanodine receptor specific to slow-twitch skeletal muscle Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2000; 279(5): R1889 - R1898. [Abstract] [Full Text] [PDF]

				D. Danieli-Betto, E. Germinario, A. Esposito, D. Biral, and R. Betto Effects of fatigue on sarcoplasmic reticulum and myofibrillar properties of rat single muscle fibers J Appl Physiol, September 1, 2000; 89(3): 891 - 898. [Abstract] [Full Text] [PDF]

				S. Choisy, C. Huchet-Cadiou, and C. Léoty Differential Effects of 4-Chloro-m-cresol and Caffeine on Skinned Fibers from Rat Fast and Slow Skeletal Muscles J. Pharmacol. Exp. Ther., September 1, 2000; 294(3): 884 - 893. [Abstract] [Full Text]

				Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease . A Statement of the American Thoracic Society and European Respiratory Society Am. J. Respir. Crit. Care Med., April 1, 1999; 159(4): S2 - 40. [Full Text] [PDF]

				J. P. C. Franck, J. Morrissette, J. E. Keen, R. L. Londraville, M. Beamsley, and B. A. Block Cloning and characterization of fiber type-specific ryanodine receptor isoforms in skeletal muscles of fish Am J Physiol Cell Physiol, August 1, 1998; 275(2): C401 - C415. [Abstract] [Full Text] [PDF]

				E. Germinario, A. Esposito, A. Megighian, M. Midrio, D. Biral, R. Betto, and D. Danieli-Betto Early changes of type 2B fibers after denervation of rat EDL skeletal muscle J Appl Physiol, May 1, 2002; 92(5): 2045 - 2052. [Abstract] [Full Text] [PDF]