HIGHLIGHTED TOPIC Role of Inflammation in Skeletal Muscle, Connective Tissue, and Exertional Injuries: To Block or Not to Block? Does an NSAID a day keep satellite cells at bay?

Mackey AL. Does an NSAID a day keep satellite cells at bay? J Appl Physiol 115: 900–908, 2013. First published May 16, 2013; doi:10.1152/japplphysiol.00044.2013.— Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely consumed by athletes worldwide, despite growing evidence for a negative influence on the adaptation of skeletal muscle to exercise, at least in young healthy individuals. This review focuses on the potential of NSAIDs to alter the activity of satellite cells, the muscle stem cell responsible for repair and maintenance of skeletal muscle. The signaling pathways that are potentially modified by NSAID exposure are also considered. Growth factors as well as inflammatory cells and connective tissue appear to be key factors in the response of muscle under conditions where cyclooxygenase and prostaglandin activity are blocked through NSAID ingestion or infusion. Discrepancies in the literature regarding the response of young and old individuals are addressed, where it appears that the elderly may benefit from NSAID ingestion, although this clearly requires further study. The long-term implications for the muscle of the apparent inhibitory effect of NSAIDs on satellite cells in younger individuals are not clear, and it is possible these may first become apparent with chronic use in athletes training at a high level or with advancing age. Reports of the potential for NSAIDs to alter prostaglandin and growth factor signaling provide a basis for further study of the mechanism of NSAID action on satellite cells.