Oestrogen-dependent satellite cell activation and proliferation following a running exercise occurs via the PI3K signalling pathway and not IGF-1

• Published in: Acta Physiologica 2014-09, Vol.212 (1), p.75-85
• Main Authors: Mangan, G., Bombardier, E., Mitchell, A. S., Quadrilatero, J., Tiidus, P. M.
• Format: Article
• Language: English
• Subjects: Animals; Cell Proliferation - drug effects; Estradiol - pharmacology; Estrogens - pharmacology; Female; Fluorescent Antibody Technique; Insulin-Like Growth Factor I - metabolism; insulin-like growth factor-1; muscle; oestrogen; Ovariectomy; Phosphatidylinositol 3-Kinases - metabolism; phosphatidylinositol-3 kinase; Physical Conditioning, Animal - physiology; Radioimmunoassay; Rats; Rats, Sprague-Dawley; satellite cells; Satellite Cells, Skeletal Muscle - drug effects; Satellite Cells, Skeletal Muscle - metabolism; Signal Transduction - physiology
• ISSN: 1748-1708; 1748-1716
• DOI: 10.1111/apha.12317

Aim The purpose of this study was to determine whether 17β‐estradiol (E2) enhances the activation, proliferation and differentiation of muscle satellite cells (SC) following eccentric exercise either via insulin‐like growth factor‐1 (IGF‐1) or through phosphatidylinositol 3‐kinase (PI3K) signalling. Methods This study used 64, 9‐week‐old, ovariectomized Sprague–Dawley rats that were divided into eight treatments groups based on oestrogen status (0.25 mg oestrogen pellet or sham), exercise status (90 min run @ 17 m min−1, −13.5° or unexercised) and PI3K signalling inhibition (0.7 mg wortmannin kg−1 body weight or DMSO control). Results Significant increases in total SCs were found in both soleus and white gastrocnemius muscles (immunofluorescent co‐localization of Pax7+ nuclei) 72 h following eccentric exercise (P