It found that by reducing the production of prostaglandins, NSAIDs change how a body responds to exertion, this time deep within the muscles. For that study, researchers in the department of microbiology at Stanford University looked first at muscle cells and tissue from mice that had experienced slight muscular injuries, comparable to those we might develop during strenuous exercise. The tissue soon filled with a particular type of prostaglandin that turned out to have an important role: It stimulated stem cells within the muscles to start multiplying, creating new muscle cells that then repaired the tissue damage. Afterward, tests showed that the healed muscle tissue was stronger than it had been before. - www.nytimes.com