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The WISE‐study 2005: Skeletal muscle changes in females subjected to 59‐days of bed rest with and without exercise countermeasures
Author(s) -
Blottner Dieter,
Schiffl Gudrun,
Püttman Britta,
Schoser Benedikt G.,
Salanova Michele
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a951
Subject(s) - bed rest , spaceflight , medicine , skeletal muscle , endocrinology , sarcolemma , muscle atrophy , myocyte , atrophy , isometric exercise , cardiology , chemistry , engineering , aerospace engineering
In a 60‐days female bed rest study (WISE), we tested if a combined exercise countermeasure protocol maintained skeletal muscle structure and protein composition, or if a leucin‐enriched diet might counteract disuse‐induced muscle protein breakdown. Three groups (n=8, each) were subjected to (i) bed rest‐only (Ctrl), (ii) resistive fly‐wheel exercise (FWE) combined with low‐body negative pressure treadmill, LBNP (Ex), and (iii) bed rest‐only with leucine‐enriched diet (Nutr). Before and after bed rest (pre vs. postBR) biopsies of vastus lateralis (VL) and soleus muscle (SOL) were taken from each subject and analysed accordingly. FWE + LBNP exercise maintained the cross‐sectional areas (CSA) of myofiber type I and II as well as the myofiber I/II pattern in both VL and SOL as compared to BR‐only Ctrl and Nutr group. Intensity of sarcolemma membrane NO‐synthase (NOS1) immunofluorescence as well as NOS1 protein expression was either decreased (Ctrl, Nutr) or increased (Ex) in both SOL and VL. MuRF‐1, a selective biomarker monitoring non‐lysosomal protein breakdown in myofibers was significantly upregulated in non‐trained groups (Ctrl, Nutr), or maintained at baseline levels (Ex). Our results provided evidence for an effective countermeasure protocol in females to circumvent ongoing atrophy during extended unloading conditions such as in future prolonged spaceflight missions. ‐ Deutsches Zentrum für Luft‐ und Raumfahrt (DLR), Germany (grant 50WB0521 to D.B.)