Radiation effects on skeletal muscle

Background. Adult skeletal muscle is considered resistant to ionizing radiation unless higher doses of radiation are applied; a fact that is attributed to the low number of radiosensitive proliferating cells in adulthood. However, developing skeletal muscles are highly sensitive to ionizing radiation, thus radiotherapy in childhood may induce muscular atrophy. Radiation affects muscle satellite cells by impairing their activation, proliferation and differentiation, as well as neuromuscular junction, by influencing the ionic membrane permeability affecting the Na+/K+ pump. It also prevents muscle growth during development and after injury. Conclusions. The results of the investigation performed after radiation point to the occurrence of a significant change in muscle satellite cell activity. Inhibitors of some proteins such as cytokines in muscle satellite cells could provide a therapeutic benefit in diseases for which muscle mass is limiting, improve response to cancer therapy, and increase life span in patients with cachexia.