Abstract
We investigated the effects of gravitational unloading on the regeneration of injured mouse soleus muscle by using proteome analysis. Male adult mice (C57BL/6J) were subjected to unloading by hindlimb suspension. Following 2-week-suspension, cardiotoxin (CTX) was injected into soleus muscles to initiate the necrosis-regeneration cycle. Ambulation in cage was allowed for one group of mice and suspension was continued for additional 4 weeks in the remaining group. Unloading, as well as CTX-injection, resulted in a rapid loss of soleus protein contents. Recovery of muscle protein content was observed in CTX-injected soleus after 4 weeks in ambulatory control group. However, there was no gain of protein content in muscle with both CTX-injection and continuous unloading. Profiles of proteins were analyzed by two-dimensional gel electrophoresis using two immobilized pH gradient strips with overlapping pH range covering a pH 3-8 range. Twenty five spots were significantly altered in muscle with CTX-injection and suspension compared with the group with CTX-injection alone. This study was supported, in part, by Grant-in-Aid for Scientific Research (C, 17500444, KG; A, 18200042, TY; S, 19100009, YO) from Japan Society for the Promotion of Science, Ground-based Research Program for Space Utilization from Japan Space Forum (KG). [J Physiol Sci. 2008;58 Suppl:S67]
