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Satellite cell count, VO 2max , and p 38 MAPK in inactive to moderately active young men
Author(s) -
Macaluso F.,
Brooks N. E.,
Vyver M.,
Tubbergh K.,
Niesler C. U.,
Myburgh K. H.
Publication year - 2012
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/j.1600-0838.2011.01389.x
Subject(s) - myogenin , medicine , endocrinology , p38 mitogen activated protein kinases , mapk/erk pathway , kinase , chemistry , biology , myocyte , biochemistry , myogenesis
Satellite cells ( SCs ) are responsible for muscle repair following strenuous exercise or injury. SC responses to intervention have been studied, but most studies do not discuss or take into account the substantial variability in SC number among young individuals. We hypothesized that an active lifestyle reflected in higher VO 2max may be associated with greater SC number. As training alters basal p 38‐mitogen‐activated protein kinase ( MAPK ) activity, which is associated with SC proliferation, SC count may also correlate with this stress signaling kinase. Muscle biopsies from vastus lateralis of eight male participants were analyzed for fiber type, myogenin, and p 38/phospho‐ p 38 MAPK using SDS ‐ PAGE and W estern blotting. Immunofluorescence was used to detect Pax 7 + SC s. Two weeks following the biopsy, subjects underwent an incremental treadmill test to determine VO 2max . A strong positive correlation ( P = 0.0087) was found between the number of Pax 7 + nuclei and VO 2max . Pax 7 + cell number correlated negatively with phospho‐p38/p38 MAPK ( P = 0.0006), but had no correlation with fiber type or myogenin. SC number is proportional to VO 2max , and hence it can be postulated that higher levels of physical activity activate SC proliferation but not fusion, underlining the relevance of exercise in stimulating SC pool size even without injury.