AJP - Cell Physiology, Vol 260, Issue 4 C841-C850, Copyright © 1991 by American Physiological Society

ARTICLES

Mitochondrial adaptations in denervated muscle: relationship to muscle performance

K. L. Wicks and D. A. Hood
Department of Physical Education, York University, North York, Ontario, Canada.

We have studied mitochondrial adaptations in muscle subject to chronic denervation, and their relationship to muscle performance, using a model of unilateral sciatic nerve denervation in rats over periods of 2, 5, 8, 14, 21, 28, 35, and 42 days (n = 5-9 rats/day). Time to peak tension (TPT), one-half relaxation time (1/2RT), and endurance performance were evaluated during in situ stimulation of denervated and contralateral gastrocnemius-plantaris muscles. Denervation led to a 70% decline in muscle mass after 42 days. TPT and 1/2RT increased 17 and 30%, respectively, indicating a transformation toward slower muscle. The activities of the enzymes cytochrome-c oxidase (CYTOX), succinate dehydrogenase, and citrate synthase were decreased by 8-14 days, and by 42 days these were 34-58% of control. The mitochondrial phospholipid cardiolipin was reduced earlier, by 5 days, and gradually decreased to 37% of control. Thus phospholipid removal appears to precede the loss of enzyme activity during decreases in mitochondrial content. Endurance performance was reduced in parallel with decreases in enzyme activity and cardiolipin. Cytochrome c mRNA levels decreased to 52% of control by 5 days. Denervation resulted in coordinated changes in mRNA levels encoding the nuclear-derived CYTOX subunit VIc and the mitochondrially derived CYTOX subunit III. However, changes in CYTOX activity did not always parallel alterations in subunit mRNA levels. Thus transcriptional and translational mechanisms operate in regulating mitochondrial gene expression during denervation.

This article has been cited by other articles:

				M. F. N. O'Leary and D. A. Hood Effect of prior chronic contractile activity on mitochondrial function and apoptotic protein expression in denervated muscle J Appl Physiol, July 1, 2008; 105(1): 114 - 120. [Abstract] [Full Text] [PDF]

				V. Ljubicic and D. A. Hood Kinase-specific responsiveness to incremental contractile activity in skeletal muscle with low and high mitochondrial content Am J Physiol Endocrinol Metab, July 1, 2008; 295(1): E195 - E204. [Abstract] [Full Text] [PDF]

				F. L. Muller, W. Song, Y. C. Jang, Y. Liu, M. Sabia, A. Richardson, and H. Van Remmen Denervation-induced skeletal muscle atrophy is associated with increased mitochondrial ROS production Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1159 - R1168. [Abstract] [Full Text] [PDF]

				P. J. Adhihetty, M. F. N. O'Leary, B. Chabi, K. L. Wicks, and D. A. Hood Effect of denervation on mitochondrially mediated apoptosis in skeletal muscle J Appl Physiol, March 1, 2007; 102(3): 1143 - 1151. [Abstract] [Full Text] [PDF]

				Z. Ashley, H. Sutherland, H. Lanmuller, M. F. Russold, E. Unger, M. Bijak, W. Mayr, S. Boncompagni, F. Protasi, S. Salmons, et al. Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year Am J Physiol Cell Physiol, January 1, 2007; 292(1): C440 - C451. [Abstract] [Full Text] [PDF]

				A. Raffaello, P. Laveder, C. Romualdi, C. Bean, L. Toniolo, E. Germinario, A. Megighian, D. Danieli-Betto, C. Reggiani, and G. Lanfranchi Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling Physiol Genomics, March 13, 2006; 25(1): 60 - 74. [Abstract] [Full Text] [PDF]

				T. Matsuura, T. Ikata, S. Takata, S. Kashiwaguchi, M. Niwa, T. Sogabe, and K. Koga Effect of weight bearing on recovery from nerve injury in skeletal muscle J Appl Physiol, November 1, 2001; 91(5): 2334 - 2341. [Abstract] [Full Text] [PDF]

				E. Smol, E. Zernicka, D. Czarnowski, and J. Langfort Lipoprotein lipase activity in skeletal muscles of the rat: effects of denervation and tenotomy J Appl Physiol, March 1, 2001; 90(3): 954 - 960. [Abstract] [Full Text] [PDF]

				D. A. Hood Plasticity in Skeletal, Cardiac, and Smooth Muscle: Invited Review: Contractile activity-induced mitochondrial biogenesis in skeletal muscle J Appl Physiol, March 1, 2001; 90(3): 1137 - 1157. [Abstract] [Full Text] [PDF]

				C. Ongvarrasopone and J. M. Kennedy Developmentally regulated expression of cytochrome-c oxidase isoforms in regenerating rat skeletal muscle J Appl Physiol, July 1, 1998; 85(1): 246 - 253. [Abstract] [Full Text] [PDF]

				M. K. Connor and D. A. Hood Effect of microgravity on the expression of mitochondrial enzymes in rat cardiac and skeletal muscles J Appl Physiol, February 1, 1998; 84(2): 593 - 598. [Abstract] [Full Text] [PDF]

				Y. Hayashi, T. Ikata, H. Takai, S. Takata, T. Sogabe, and K. Koga Time course of recovery from nerve injury in skeletal muscle: energy state and local circulation J Appl Physiol, March 1, 1997; 82(3): 732 - 737. [Abstract] [Full Text] [PDF]