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Journal of Biomedicine and Biotechnology
Volume 2011 (2011), Article ID 401493, 8 pages
http://dx.doi.org/10.1155/2011/401493
Research Article

The Combined Effect of Electrical Stimulation and High-Load Isometric Contraction on Protein Degradation Pathways in Muscle Atrophy Induced by Hindlimb Unloading

1Department of Rehabilitation Science, Graduate School of Health Sciences Kobe University, 7-10-2 Tomogaoka, Suma-Ku, Kobe 654-0142, Japan
2Department of Physical Therapy, Himeji Dokkyo University, 7-2-1 Kamiono, Himeji 670-8524, Japan

Received 20 May 2011; Revised 1 August 2011; Accepted 1 August 2011

Academic Editor: J.-P. Jin

Copyright © 2011 Naoto Fujita et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

High-load isometric exercise is considered an effective countermeasure against muscle atrophy, but therapeutic electrical stimulation for muscle atrophy is often performed without loading. In the present study, we investigated the combined effectiveness of electrical stimulation and high-load isometric contraction in preventing muscle atrophy induced by hindlimb unloading. Electrical stimulation without loading resulted in slight attenuation of muscle atrophy. Moreover, combining electrical stimulation with high-load isometric contraction enhanced this effect. In electrical stimulation without loading, inhibition of the overexpression of calpain 1, calpain 2, and MuRF-1 mRNA was confirmed. On the other hand, in electrical stimulation with high-load isometric contraction, inhibition of the overexpression of cathepsin L and atrogin-1 mRNA in addition to calpain 1, calpain 2, and MuRF-1 mRNA was confirmed. These findings suggest that the combination of electrical stimulation and high-load isometric contraction is effective as a countermeasure against muscle atrophy.