Oxytocin: New Wonder Hormone That May Reduce Muscle Aging
Oxytocin, secreted by the posterior pituitary, is not a new hormone. Nor is its importance for the biological health of the organism something new. Oxytocin has been known about for many years. It was known to be instrumental in helping uterine contraction during childbirth, for enhancing breast contraction during breast feeding, and even more recently, it has been found to be instrumental in helping to establish bonds between parents and infants as well as enhance bonding and trust in social relationships. Furthermore, oxytocin increases dramatically during sexual intercourse, and has often been referred to as the love hormone. However, this hormone that already has been found to be so instrumental in so many areas of our life is now providing us with new findings, and these findings may be the most significant yet.
Recent research out of the University of California, Berkeley has found that oxytocin may help to heal and reverse atrophic changes in muscles as we age, countering many of the sarcopenic changes in muscle mass and strength that is often found among older adults. This is a particularly important discovery since falls resulting in severe injuries, such as fractures, exist at epidemic proportions in the elderly. Generally, the probability for such falls and injuries, some even resulting in death, are due to muscle weakness associated with aging.
In studies on mice, injections of oxytocin on a subdermal level enhanced the regenerative potential of muscle in aging mice. Older mice that were given oxytocin injections demonstrated greater muscle healing and regeneration as compared to those older mice that did not receive oxytocin injections. Furthermore, the oxytocin appeared to work on muscle healing and muscle regeneration very quickly. As one of the lead researchers, Christian Elabd stated, "The action of oxytocin was fast ... The repair of muscle in the old mice was at about 80 percent of what we saw in the young mice"1. This is an incredible reversal, with older mice having a repair and regenerative potential that is 80 percent of the more youthful mice.
The synthetic form of oxytocin has existed for years to assist women with delivery. Since the Food and Drug Administration already has a synthetic agent approved, if the hormone continues to show promising results, using the already approved synthetic form could be very important in bringing it to use for diseases related to aging. Since it already has been brought to market and is in use, the already approved drug could lead to new therapeutic interventions for reversing muscle aging in the near future.
One of the first clues that oxytocin might have important effects on muscle cells was when scientists noticed that women who had their ovaries removed also experienced a reduction in oxytocin levels. They also noted that the precursor cells to mature muscles cells had oxytocin receptors. Since many ovarectomized women experienced effects that were similar to those found in aging individuals in their muscle tissue, they hypothesized that a connection between oxytocin and muscle aging may exist.
There is also further good news about the introduction of oxytocin into the bodies of mice. In young mice it did not seem to cause an appreciable effect in changing muscle regeneration. At first this may not seem very encouraging. However, it points to important safety concerns. Since oxytocin appears to focus on aging stem cells without affecting more youthful muscle, this seems to address the issue of whether it may lead to controllable mitotic division, leading to cancerous changes. In this case since it did not appear to do so in the more youthful mice, the drug appears to have answered some important concerns about its safety.
The reduction of oxytocin in later years may also be strongly genetically driven. The researchers investigated the oxytocin gene and the effects of the gene after it was disabled. They found that when they disabled the gene it did not automatically manifest results when the mice were young. However, as the mice became older, they started to show early senescent changes, aging changes that occurred at ages much earlier than one would anticipate and as compared to a control group of mice who did not experience the genetic manipulation.
Although these are exciting results, one has to be cautious against using terminology and references to oxytocin as an "anti-aging" drug or hormone. Senescence is a natural process. There is nothing that reverses aging or is an "anti-aging" remedy as some will have you believe through media sources. Yet, the important scientific finding that oxytocin may help regenerate muscle may eventually lead toward helping address many diseases and the symptoms of these diseases that are often associated with aging. Furthermore, it may help prevent many injuries such as falls resulting in fractures, especially of the hip, that often result in premature mortality.
Oxytocin is an exciting agent. It became known almost exclusively for its biological effects during childbirth and infant feeding. However, recently, just over the last couple of decades, the research on oxytocin has shown that it also has important social effects on individuals, especially regarding bonding and trust. And now comes another connection with this hormone that is growing in stature. In fact, this may be the most important one of all, and may have important implications for enhancing healthy aging and eliminating many common diseases or illnesses associated with aging. Is it not deserving of being known as the "wonder hormone"?
1. Choi, C. (2014/June 11). Aging Muscles May Just Need a Little 'Love Hormone.' LiveScience. Accessed at: http://news.yahoo.com/aging-muscles-may-just-little-love-hormone-140029679.html