Human skeletal muscle structure and function preserved by vibration muscle exercise following 55 days of bed rest
- 1.1k Downloads
Prolonged immobilization of the human body results in functional impairments and musculoskeletal system deconditioning that may be attenuated by adequate muscle exercise. In a 56-day horizontal bed rest campaign involving voluntary males we investigated the effects of vibration muscle exercise (RVE, 2×6 min daily) on the lower limb skeletal muscles using a newly designed foot plantar trainer (Galileo Space) for use at supine position during bed rest. The maximally voluntary isometric plantar flexion force was maintained following regular RVE bouts during bed rest (controls −18.6 %, P<0.05). At the start (BR2) and end of bed rest (BR55) muscle biopsies were taken from both mixed fast/slow-type vastus lateralis (VL) and mainly slow-type soleus muscle (SOL), each having n=10. RVE group: the size of myofiber types I and II was largely unchanged in VL, and increased in SOL. Ctrl group: the SOL depicted a disrupted pattern of myofibers I/II profiles (i.e., type II>140 % vs. preBR) suggesting a slow-to-fast muscle phenotype shift. In RVE-trained SOL, however, an overall conserved myofiber I/II pattern was documented. RVE training increased the activity-dependent expression of nitric oxide synthase type 1 immunofluorescence at SOL and VL myofiber membranes. These data provide evidence for the beneficial effects of RVE training on the deconditioned structure and function of the lower limb skeletal muscle. Daily short RVE should be employed as an effective atrophy countermeasure co-protocol preferentially addressing postural calf muscles during prolonged clinical immobilization or long-term human space missions.
KeywordsSkeletal muscle atrophy Neuromuscular disorders Countermeasure Rehabilitation Spaceflight
This study was supported by grants from the ESA, grant # 14431/02/NL/SH2, Center for Muscle and Bone Research (ZMK), Charité Campus Benjamin Franklin, Berlin (to D.F.), German AeroSpace (DLR), Center of Space Medicine Berlin (ZWMB, http://www.zwmb.de), Charité CBF, grant # 50WB0145 (to D.B.). Special thanks go to the volunteers, the staff of the Radiology Department at CBF, and to all enthusiastic participants of the Berlin Bed Rest Study 2003 and 2004.
- Harris JA, Benedict FG (1919) A biometric study of basal metabolism in man. Carnegie Institute of Washington, WashingtonGoogle Scholar
- Rudnick J, Püttmann B, Tesch PA, Alkner B, Schoser BG, Salanova M, Kirsch K, Gunga HC, Schiffl G, Lück G, Blottner D (2004) Differential expression of nitric oxide synthases (NOS 1–3) in human skeletal muscle following exercise countermeasure during 12 weeks of bed rest. FASEB J 18:1228–30PubMedGoogle Scholar