Accession Number : ADA630337


Title :   The Impact of Muscle Disuse on Muscle Atrophy in Severely Burned Rats


Descriptive Note : Journal article


Corporate Author : ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX


Personal Author(s) : Wu, Xiaowu ; Baer, Lisa A ; Wolf, Steen E ; Wade, Charles E ; Walters, Thomas J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a630337.pdf


Report Date : Dec 2010


Pagination or Media Count : 17


Abstract : Background Severe burn induces a sustained hypermetabolic response, which causes long-term loss of muscle mass and decrease in muscle strength. In this study, we sought to determine whether muscle disuse has additional impact on muscle atrophy after severe burn using a rat model combining severe cutaneous burn and hindlimb unloading. Methods Forty Sprague-Dawley rats ( identical with 300g) were randomly assigned to sham ambulatory (S/ A), sham hindlimb unloading (S/HLU), burn ambulatory (B/A) or burn hindlimb unloading (B/ HLU) groups. Rats received a 40% total body surface (TBSA) full thickness scald burn, and rats with hindlimb unloading were placed in a tail traction system. At day 14, lean body mass (LBM) was determined using DEXA scan, followed by measurement of the isometric mechanical properties in the predominantly fast-twitch plantaris muscle (PL) and the predominantly slow- twitch soleus muscle (SL). Muscle weight (wt), protein wt, and wet/dry wt were determined. Results At day 14, body weight had decreased significantly in all treatment groups; B/HLU resulted in significantly greater loss compared to the B/A, S/HLU and S/A. The losses could be attributed to loss of LBM. PL muscle wt and Po were lowest in the B/HLU group (less than 0.05 vs. S/A, S/HLU or B/A). SL muscle wt and Po were significantly less in both S/HLU and B/HLU compared that of S/A and B/A; no significant difference was found between S/HLU and B/HLU. Conclusions Cutaneous burn and hindlimb unloading have an additive effect on muscle atrophy, characterized by loss of muscle mass and decrease in muscle strength in both fast (PL) and slow (SL) twitch muscles. Of the two, disuse appeared to be the dominant factor for continuous muscle wasting after acute burn in this model.


Descriptors :   *ATROPHY , *BURNS(INJURIES) , *MUSCLES , *RATS , ANATOMICAL MODELS , BODY WEIGHT , EXTREMITIES , HYPERMETABOLISM , PHYSIOLOGICAL EFFECTS , PROTEINS , REGENERATIVE MEDICINE , RESPONSE(BIOLOGY) , SKIN(ANATOMY) , STRENGTH(PHYSIOLOGY) , TRAUMA


Subject Categories : Anatomy and Physiology
      Medicine and Medical Research


Distribution Statement : APPROVED FOR PUBLIC RELEASE