Mechanotherapy does not Enhance Recovery Following Muscle Disuse Atrophy in Female Rats

• Published in: The FASEB journal 2022-05, Vol.36 (S1), p.n/a
• Main Authors: Sklivas, Alexander B., Rose, Sarah, Abbott, Claire, Miller, Benjamin, Butterfield, Tim, Dupont‐Versteegden, Esther
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.2022.36.S1.R4852

Background Recovery from skeletal muscle atrophy is important for regaining function. We previously showed that mechanotherapy enhances regrowth of muscle in adult male rats by elevating protein synthesis. Objective The purpose of this study was to determine if female rats also respond to mechanotherapy during regrowth after disuse‐induced atrophy. Hypothesis Mechanotherapy in female rats augments muscle regrowth after atrophy by enhancing protein synthesis. Methods Adult (10 month) F344/BN female rats were randomly assigned to one of four groups: weight‐bearing (WB; N=6), hindlimb suspension (HS; N=9), reambulation after HS without mechanotherapy (RA; N=9), or RA with mechanotherapy (RAM; N=10). HS lasted for 14 and RA for 7 days. Starting the day of RA, mechanotherapy was applied to the right gastrocnemius muscle at a load of 4.5N for 30 minutes every other day (4 bouts total). Rats received deuterium oxide (D2O) for determination of myofibrillar protein and RNA synthesis (Ksyn) and degradation (Kdeg). We analyzed gastrocnemius muscles for myonuclear number (dystrophin‐DAPI), satellite cell (SC) number (Pax7), and fiber type and cross‐sectional area (CSA; laminin‐myosin heavy chain). We used a one‐way ANOVA to determine statistical significance at p