Satellite cell count, VO 2max, and p38 MAPK in inactive to moderately active young men
Date
2012
Authors
Macaluso F.
Brooks N.E.
van de Vyver M.
Van Tubbergh K.
Niesler C.U.
Myburgh K.H.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
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 p38-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 p38/phospho-p38 MAPK using SDS-PAGE and Western blotting. Immunofluorescence was used to detect Pax7
+ SCs. 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 Pax7
+ nuclei and VO
2max. Pax7
+ 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. © 2011 John Wiley & Sons A/S.
Description
Article
Keywords
Fiber type, Myogenin, Pax7
+, Physical fitness, Vastus lateralis muscle
Citation
Scandinavian Journal of Medicine and Science in Sports
22
4
e38
e44
22
4
e38
e44