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Trust hormone oxytocin helps old muscle work like new, study finds
By Sarah Yang, Media Relations | June 10, 2014
BERKELEY
UC Berkeley researchers have discovered that oxytocin a hormone associated with maternal nurturing, social attachments, childbirth and sex is indispensable for healthy muscle maintenance and repair, and that in mice it declines with age [and that restoring youthful levels restores youthful muscle repair capacity -MR].
The new study, [(1) below] ... presents oxytocin as the latest treatment target for age-related muscle wasting, or sarcopenia. ...[and] the first anti-aging molecule identified that is approved by the Food and Drug Administration for clinical use in humans ... to help with labor and to control bleeding after childbirth. Clinical trials of an oxytocin nasal spray are also underway to alleviate symptoms associated with mental disorders such as autism, schizophrenia and dementia.
Unfortunately, most of the molecules discovered so far to boost tissue regeneration are also associated with cancer... said study principal investigator Irina Conboy ... [O]xytocin... is not known to be associated with tumors or to interfere with the immune system.
Oxytocin ... is released with a warm hug, a grasped hand or a loving gaze, and it increases libido. The hormone kicks into high gear during and after childbirth, helping new mothers bond with and breastfeed their new babies. ... [I]n mice, blood levels of oxytocin declined with age ... [and] there are fewer receptors for oxytocin in muscle stem cells in old versus young mice. ... [W]hile oxytocin is found in both young boys and girls, it is not yet known when levels of the hormone start to decline in humans, and what levels are necessary for maintaining healthy tissues. ...
Previous research by [lead author] Elabd found that administering oxytocin helped prevent the development of osteoporosis in mice that had their ovaries removed to mimic menopause. ... To tease out oxytocins role 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. ... [A]t about 80 percent of what we saw in the young mice.
The healthy muscle tissue on the left is from a young mouse. The ability of muscle to repair itself decreases with age, as evidenced by the middle image of old muscle tissue, which shows a lower density of muscle fibers, increased scar tissue and inflammation. The addition of oxytocin to the blood of old mice rapidly rejuvenates the old muscle, as shown on the right. (Photos by Wendy Cousin and Christian Elabd, UC Berkeley)
Interestingly, giving young mice an extra boost of oxytocin did not seem to cause a significant change in muscle regeneration. ... [But] blocking the effects of oxytocin in young mice rapidly compromised their ability to repair muscle, which resembled old tissue after an injury ... [M]ice whose gene for oxytocin was disabled ... [suffered no decline in repair capacity in youth]. ... It wasn't until the mice with the disabled oxytocin gene reached adulthood that signs of premature aging began to appear. ...
[Investigator] 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 aging, and for long-term health. ... In addition to healthy muscle, oxytocin is predicted to improve bone health, and it might be important in combating obesity.
Conboy said her lab plans to examine oxytocins role in extending a healthy life in animals, and in conserving its beneficial anti-aging effects in humans. ...
Funding from the SENS Research Foundation, the National Institute on Aging and the California Institute for Regenerative Medicine helped support this research.
Note that this is work in Irina Conboy lab. Conboy is famous for heterochronic parabiosis work, which has featured several times on the List in recent months; oxytocin now appears as one of the factors potentially involved in the rejuvenating effect of young serum.
Conboy is about to start a mega-project on identifying the interactions of factors involved in the 'parabiotic effect' and their interactions with structural repair rejuvenation biotechnologies, also funded by SENS Research Foundation (note my affiliation) and with much of the hands-on work carried out by Justin Rebo (Illuminatus here at Longecity).
-Michael
1. Christian Elabd, Wendy Cousin, Pavan Upadhyayula, Robert Y. Chen, Marc S. Chooljian, Ju Li, Sunny Kung, Kevin P. Jiang & Irina M. Conboy
Oxytocin is an age-specific circulating hormone that is necessary for muscle maintenance and regeneration
Nature Communications 5, Article number: 4082
doi:10.1038/ncomms5082
Published 10 June 2014
http://www.nature.co...ncomms5082.html
Edited by Michael, 10 June 2014 - 11:07 PM.