Peroxisome proliferator activated receptor gamma 1-alpha coactivator (PGC-1 alpha) is a specific myokine since it stimulates satellite cells, but stimulates M1 and M2 macrophages; M1 macrophages release interleukin 6 (IL-6), Insulin growth factor type 1 (IGF-1) and vascular endothelial growth factor (VEGF), while M2 macrophages mainly secrete IGF-1, VEGF and monocyte chemoattractant protein 1 (MCP-1)) and all this process the muscle becomes muscle hypertrophy.
Macrophages M2 stimulate satellite cells for proliferation and growth but M1 stimulates blood vessels and produces pro-inflammatory cytokines only M2 produces anti-inflammatory in muscles.