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Differential expression of nitric oxide synthases (NOS 1‐3) in human skeletal muscle following exercise countermeasure during 12 weeks of bed rest
Author(s) -
Rudnick Jana,
Püttmann Britta,
Tesch Per A.,
Alkner Björn,
Schoser Benedikt G. H.,
Salanova Michele,
Kirsch Karl,
Gunga Hanns-Christian,
Schiffl Gudrun,
Lück Gabriele,
Blottner Dieter
Publication year - 2004
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/fj.03-0792fje
Subject(s) - skeletal muscle , medicine , muscle atrophy , endocrinology , nitric oxide synthase , immunostaining , atrophy , nitric oxide , myocyte , chemistry , endurance training , spaceflight , bed rest , immunohistochemistry , engineering , aerospace engineering
Adaptive changes of major body systems in astronauts during spaceflight can be simulated by strict anti‐orthostatic head‐down tilt (HDT) bed rest (BR), a ground‐based microgravity (μG) model that provides a meaningful opportunity to study atrophy mechanisms and possible countermeasures under controlled experimental conditions. As nitric oxide (NO) signaling is linked to muscle activity, we investigated altered expression of the three major isoforms of nitric oxide synthase (NOS 1–3) at cellular compartments during prolonged HDT BR without (control group) and with resistance exercise interventions (exercise group) using a flywheel ergometer (FWE). Atrophy detected in mixed (fast–slow) m. vastus lateralis (VL) and slow‐type m. soleus (SOL) myofiber Types I and II (minus 35–40% of myofiber cross‐sectional area) was prevented by FWE training. Concomitant to muscle atrophy, reduced NOS 1 protein and immunostaining was found in VL not in SOL biopsies. In trained VL, NOS 1 protein and immunostaining at myofibers II were significantly increased at the end of BR. Exercise altered NOS 2/caveolin 3 co‐immunostaining patterns of subsarcolemmal focal accumulations in VL or SOL myofibers, which suggests reorganization of sarcolemmal microdomains. In trained VL, increased capillary‐ to‐fiber (C/F) ratio and NOS 3 protein content were documented. Activity‐linked NO signaling may be widespread in skeletal muscle cellular compartments that may be directly or indirectly impacted by adequate exercise countermeasure protocols to offset the negative effects induced by disuse, immobilization, or extended exposure to microgravity.