Rejuvenating old muscles

Muscle cells before and after addition of oxytocinIrina Conboy’s bioengineering lab found that aging muscle cells in mice naturally degenerate (at left), but appear revitalized after oxytocin is administered (at right).Your muscles grow larger and stronger from birth until your thirties, when they naturally start to lose mass, strength and mobility. Now, bioengineering researchers have discovered that oxytocin—the hormone associated with maternal nurturing, social attachments, childbirth and sex—may combat this age-related muscle wasting. Led by associate professor Irina Conboy, Berkeley researchers found that mice required oxytocin for healthy muscle maintenance and repair, and oxytocin levels in blood and receptors in muscle stem cells reduce with age. When they injected oxytocin into older mice, the researchers found that it improved muscle regeneration to a level comparable to young mice, with no ill effects. “This demonstrates that extra oxytocin boosts aged tissue stem cells without making muscle stem cells divide uncontrollably,” explains project scientist Wendy Cousin. Also, by experimentally inhibiting oxytocin, researchers detected premature aging in adult mice. Cousin noted that related investigations will determine if oxytocin is a viable alternative to hormone replacement therapy to impede the effects of aging in humans.


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