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Young blood rejuvenates old mice

AP

Older mice got stronger, exercised longer and performed better mentally after they were injected with blood from young mice, or even just with a substance that is more abundant in younger blood, U.S. researchers have found.

Someday, this may lead to a way to treat some infirmities of old age in people.

Saul Villeda of the University of California, San Francisco, an author of one of three papers published Sunday by Nature Medicine and Science, said the researchers are trying to figure out what in the young blood made the difference.

The two other papers, from Harvard University, focused on a substance that is more abundant in the blood of younger mice. That protein, called GDF11, is also found in human blood and its concentration in people also appears to decline with age, said Amy Wagers, an author on both papers.

On average, aging mice that got injections of it showed greater grip strength and more endurance on a treadmill than untreated mice.

The Harvard scientists also found that exposing older mice to the blood of younger mice produced more blood vessels and blood flow in the brain. Injections of GDF11 had a similar effect.