Young Blood Rejuvenates Old Muscles

Young blood can help revive damaged older muscles, according to a study that found the blood of aged mice somehow hinders a muscle's ability to repair itself.

The Study

In the Study, researchers at Stanford University focused on specialized cells called satellite cells, which are stem cells sprinkled throughout muscle tissue. These satellite cells are normally dormant but spring into action whenever muscles in young mice are damaged. However, in older mice, satellite cells do not appear to respond to muscle damage.

The Stanford researchers connected a group of older mice with a group of younger mice in a way that allowed both groups to share the same supply of blood. The researchers then induced muscle damage in the older mice. When these older mice were given blood from older mice, their muscles healed slowly. But when the older mice received blood from younger mice, their muscles healed much more quickly.

The researchers also studied the livers of older mice who received blood from younger mice. They found cells that help liver tissue regenerate were more active in older mice when they received young blood.

Implications

These findings indicate that something in younger blood revives regenerative cells in muscle and in the liver, the researchers say.

Lead researcher Dr. Thomas Rando, associated professor of neurology and neurological services at Stanford, suggests that age-related problems in the chemicals surrounding the satellite cells, not the cells themselves, might be at fault.