‘Love’ Hormone Oxytocin Boosts Muscle Repair and Maintenance, Scientists Find

Rebecca Lewis June 16, 2014

Oxytocin – the hormone associated with maternal nurturing, childbirth, social connection and sex – does more than promote your well-being. New research found that it is also indispensable in the maintenance and repair of muscles.

The study, published in the journal Nature, suggests that the ‘love hormone’ could be a potential treatment for sarcopenia or muscle wasting.

The Study

To assess the role of oxytocin in muscle repair, the researchers injected the hormone under the skin of old mice for four days, and then for five days more after the muscles were injured. After the nine-day treatment, they found that the muscles of the mice that had received oxytocin injections healed far better than those of a control group of mice without oxytocin.

Interestingly, giving young mice an extra boost of oxytocin did not seem to cause a significant change in muscle regeneration.

"This is good because it demonstrates that extra oxytocin boosts aged tissue stem cells without making muscle stem cells divide uncontrollably," says Wendy Cousin, co-researcher from the University of California, Berkeley.

They also found that blocking the effects of oxytocin in young mice rapidly compromised their ability to repair muscle, which resembled old tissue after an injury.

The researchers also studied mice whose gene for oxytocin was disabled, and compared them with a group of control mice. At a young age, there was no significant difference between the two groups in muscle mass or repair efficiency after an injury. It wasn’t until the mice with the disabled oxytocin gene reached adulthood that signs of premature aging began to appear.

"When disabling other types of genes associated with tissue repair, defects appear right away either during embryonic development, or early in life," says lead author Irina Conboy, associate professor of bioengineering. "To our knowledge, the oxytocin gene is the only one whose impact is seen later in life, suggesting that its role is closely linked to the aging process."

Anti-ageing molecule with no known risks

Cousin noted that oxytocin could become a viable alternative to hormone replacement therapy as a way to combat the symptoms of both female and male ageing. According to the researchers, oxytocin is the first anti-aging molecule identified that is approved by the Food and Drug Administration for clinical use in humans. Apart from the fact that it reaches almost every organ, it is not known to be associated with tumours or to interfere with the immune system, unlike the other anti-ageing molecules identified in the past.

"If you target processes associated with aging, you may be tackling those diseases at the same time," said Conboy. "Aging is a natural process, but I believe that we can meaningfully intervene with age-imposed organ degeneration, thereby slowing down the rate at which we become progressively unhealthy."

Source of this article:

Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration