London: A key factor which slows down muscle repair during ageing can also be reversed, potentially opening the way to their renewal, says a study conducted on mice.

Researchers from King's College London, Harvard University and Massachusetts General Hospital, provided clues as to how muscles lose mass with age, affecting mobility.

They looked at stem cells found inside muscle, which help repair injuries, to find out why muscles lose the ability to regenerate with age, the journal Nature reports.

Screening of the old muscles revealed high levels of FGF2, a protein that triggers cellular division to help muscle repair, but could also awaken the dormant pool of stem cells even when they were not needed, depleting the pool and impairing muscle repair, according to King's College statement.

Subsequently, researchers tried to inhibit FGF2 in old muscles to prevent the activation of stem cell pool unnecessarily. By administering a common FGF2 inhibitor drug, they were able to inhibit the decline in the number of muscle stem cells in the mice.

"Preventing or reversing muscle wasting in old age in humans is still a way off, but this study has for the first time revealed a process which could be responsible for age-related muscle wasting, which is extremely exciting," Albert Basson, senior lecturer at the King's College London Dental Institute, said.