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Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission
Author(s) -
Jespersen J. G.,
Mikkelsen U. R.,
Nedergaard A.,
Thorlund J. B.,
Schjerling P.,
Suetta C.,
Christensen P. A.,
Aagaard P.
Publication year - 2015
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12170
Subject(s) - muscle mass , messenger rna , glycogen , medicine , foxo1 , chemistry , biology , endocrinology , microbiology and biotechnology , phosphorylation , protein kinase b , gene , biochemistry
In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance ( SSR ) missions, S pecial F orces soldiers sustain 1–2 weeks full‐body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and strength are necessary in combat or evacuation situations, which prompt for improved understanding of muscle mass modulation during SSR missions. To explore the molecular regulation of myofiber size during a simulated SSR operation, nine male S pecial F orces soldiers were biopsied in m. vastus lateralis pre and post 8 days immobilizing restricted prone position. After immobilization, total mammalian target of rapamycin protein was reduced by 42% ( P < 0.05), whereas total and phosphorylated protein levels of A kt, ribosomal protein S 6k, 4 E ‐ BP 1, and glycogen synthase kinase3β were unchanged. Messenger RNA ( mRNA ) levels of the atrogenes forkhead box O3 ( F ox O 3), atrogin1, and muscle ring finger protein1 ( M u RF 1) increased by 36%, 53%, and 71% ( P < 0.01), M u RF 1 protein by 51% ( P = 0.05), whereas F ox O 1 and peroxisome proliferator‐activated receptor γ coactivator‐1 β mRNAs decreased by 29% and 40% ( P < 0.01). In conclusion, occupational immobilization in S pecial F orces soldiers led to modulations in molecular muscle mass regulators during 8 days prone SSR mission, which likely contribute to muscle loss observed in such operations. The present data expand our knowledge of human muscle mass regulation during short‐term immobilization.