Oxytocin, sometimes called the “love” or “trust” hormone because of its association with romance and friendship, also plays a very different role. Researchers at the University of California, Berkeley, have found that it helps to maintain healthy muscles – and in mice, oxytocin injections can rejuvenate muscles weakened by old age.
Published in Nature Communications, the study suggests that oxytocin therapy could be an option for people suffering from sarcopenia (muscle wasting in old age). “Unfortunately, most of the molecules discovered so far to boost tissue regeneration are also associated with cancer, limiting their potential as treatments for humans,” says principal investigator Irina Conboy. “Our quest is to find a molecule that not only rejuvenates old muscle and other tissue, but that can do so without increasing the risk of cancer.”
Oxytocin, secreted into the blood by the pituitary gland, is a good candidate because it is a wide-ranging hormone that apparently does not cause cancer or affect the immune system. Oxytocin injections are already used to help women during childbirth, and clinical trials are assessing the potential of oxytocin nasal spray to alleviate symptoms of mental disorders.
The study showed that oxytocin injections over nine days restored the healing ability of muscles in old mice. “The repair of muscle in the old mice was at about 80 per cent of what we saw in the young,” says Christian Elabd, co-author.
The researchers also investigated mice whose oxytocin gene was disabled. Their muscles were very similar to normal when young but later aged prematurely. “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 ageing process,” says Conboy.