A recent study has found a surprising link between muscle tissue and the pituitary gland that may impact female fertility.
Researchers from McGill University discovered that a specific protein produced by muscles influences the release of a hormone generated by the small pituitary gland located at the brain’s base.
The research, published in Science, could pave the way for new infertility treatments, according to the team.
“Previously, we didn’t realize these two organs communicated or the nature of their interaction,” explained senior author Daniel Bernard, a Professor in McGill’s Department of Pharmacology and Therapeutics. “This finding enhances our understanding of the body’s intricate networks.”
The Unexpected Consequences of Muscle Growth
The focus of the study was follicle-stimulating hormone (FSH), produced by the pituitary, which is crucial for the development of eggs in the ovaries. A lack of FSH can lead to infertility.
The muscle protein identified—myostatin—serves as the body’s natural inhibitor of muscle development.
In experiments with mice, the researchers observed that reducing myostatin levels resulted in delayed puberty and lower fertility. While restoring myostatin levels led to increased FSH production, the impact on fertility remains to be confirmed.
There are drugs currently being designed to inhibit myostatin to promote muscle growth, particularly for treating diseases like muscular dystrophy. Pharmaceutical companies are also investigating whether blocking myostatin could help maintain muscle mass in individuals using GLP-1 receptor weight-loss medications, such as Ozempic, which often cause both fat and muscle deterioration.
However, this study raises potential health concerns regarding myostatin inhibition.
“Our research showed that drugs intended for muscle-wasting conditions resulted in decreased FSH levels in female mice. Although these medications can effectively enhance muscle growth, they could disrupt reproductive hormone functions and affect fertility,” noted first author Luisina Ongaro, a research associate in Bernard’s lab.
This discovery also prompts further investigation into whether natural differences in myostatin levels could account for variations in puberty onset, missed menstrual cycles in female athletes, and unexplained infertility issues.
The researchers intend to explore if their findings from mice are applicable to humans, and they are optimistic about the possibilities.
This research received support from The Canadian Institutes of Health Research.
