AJP - Cell Physiology, Vol 254, Issue 5 C591-C604, Copyright © 1988 by American Physiological Society

ARTICLES

On the composition of the cytosol of relaxed skeletal muscle of the frog

R. E. Godt and D. W. Maughan
Department of Physiology and Endocrinology, Medical College of Georgia, Augusta 30912.

This review summarizes a variety of estimates for the concentrations of the principal cytosolic constituents in frog skeletal muscle. From these estimates (listed in the APPENDIX), we chose representative values and used electroneutrality and osmotic considerations to ensure that all major constituents have been considered. Given total cytosolic concentrations of these constituents from the literature, we employed a computer program to calculate the concentrations of all the major ionic species in the cytosol. In relaxed muscle, electroneutrality and osmotic constraints are fulfilled if, in addition to diffusible species, the charge contribution of the myofilaments is considered. Mean buffer power of the diffusible cytosolic species is calculated to be less than one-third of that experimentally determined for whole muscle. Computations indicate that recent estimates of intracellular free magnesium concentration approximately 1 mM are likely to be correct.

This article has been cited by other articles:

				R. L. Wardle, M. Gu, Y. Ishida, and R. J. Paul Rho kinase is an effector underlying Ca2+-desensitizing hypoxic relaxation in porcine coronary artery Am J Physiol Heart Circ Physiol, July 1, 2007; 293(1): H23 - H29. [Abstract] [Full Text] [PDF]

				M. Gu, G. D Thorne, R. L Wardle, Y. Ishida, and R. J Paul Ca2+-independent hypoxic vasorelaxation in porcine coronary artery J. Physiol., February 1, 2005; 562(3): 839 - 846. [Abstract] [Full Text] [PDF]

				M. Zaniboni, P. Swietach, A. Rossini, T. Yamamoto, K. W. Spitzer, and R. D. Vaughan-Jones Intracellular proton mobility and buffering power in cardiac ventricular myocytes from rat, rabbit, and guinea pig Am J Physiol Heart Circ Physiol, August 7, 2003; 285(3): H1236 - H1246. [Abstract] [Full Text] [PDF]

				F. Cifuentes, J. Vergara, and C. Hidalgo Sodium/calcium exchange in amphibian skeletal muscle fibers and isolated transverse tubules Am J Physiol Cell Physiol, July 1, 2000; 279(1): C89 - C97. [Abstract] [Full Text] [PDF]

				B. M. MILLMAN The Filament Lattice of Striated Muscle Physiol Rev, April 1, 1998; 78(2): 359 - 391. [Abstract] [Full Text] [PDF]

				H. R. Stennicke and G. S. Salvesen Biochemical Characteristics of Caspases-3, -6, -7, and -8 J. Biol. Chem., October 10, 1997; 272(41): 25719 - 25723. [Abstract] [Full Text] [PDF]

				G. Meissner, E. Rios, A. Tripathy, and D. A. Pasek Regulation of Skeletal Muscle Ca2+ Release Channel (Ryanodine Receptor) by Ca2+ and Monovalent Cations and Anions J. Biol. Chem., January 17, 1997; 272(3): 1628 - 1638. [Abstract] [Full Text] [PDF]

				S. Howell, W.-Z. Zhan, and G. C. Sieck Diaphragm disuse reduces Ca2+ uptake capacity of sarcoplasmic reticulum J Appl Physiol, January 1, 1997; 82(1): 164 - 171. [Abstract] [Full Text] [PDF]

				D. P. Dobesh, J. P. Konhilas, and P. P. de Tombe Cooperative activation in cardiac muscle: impact of sarcomere length Am J Physiol Heart Circ Physiol, March 1, 2002; 282(3): H1055 - H1062. [Abstract] [Full Text] [PDF]