A new study developed by researchers at the Massachusetts General Hospital, in the United States, has managed to explain why people with red hair have a greater tolerance to pain. It is due to an increased activity of the opioid receptors involved in blocking pain, which is combined with a reduction in the production of hormones involved in sensitivity.
According to a Press release, the research results could be used to personalize treatments for men and women with these characteristics. For example, the inability of redheaded people to tan or darken their skin is due to a specific cellular mechanism that, based on these discoveries, could be modified in the future.
In the same sense, the presence of different pain thresholds may be considered by health professionals when planning therapies or interventions.
Although it was already known that humans, mice and specimens of other animal species with red hair have a different tolerance to pain, the findings of the study published in Science Advances now allow us to know the processes and mechanisms that underlie the presence of various pain thresholds based on history of pigmentation.
A hormonal process
The scientists discovered that pigment-producing cells in the skin, called melanocytes, contain a different typology of the hormone receptor melanocortin 1 in people with red hair. It is precisely the activity of these hormones that causes melanocytes to produce brown, black, yellow or red pigments, marking the different types of skin tones.
The variations in the aforementioned hormonal receptor not only mark the tones or pigments: they also cause the melanocytes to produce lower levels of a molecule that after a long process is divided into different hormones, some aimed at blocking sensitivity to pain and others to empower it. And it is here precisely where the axis of the discovered mechanism is located.
The presence of these hormones maintains a balance between opioid receptors that inhibit pain and receptors for the hormone melanocortin 4, dedicated to improving pain perception. In red-haired people, the researchers found an increase in the activity of inhibitory factors and a reduction in pain-enhancing agents.
As a result of this process, red-haired men and women or animals with this condition have different pain thresholds. In other words, they are able to better withstand some types of pain from the hormonal modifications previously indicated.
For David E. Fisher, one of the study authors, “understanding this mechanism provides validation of previous evidence and valuable recognition for medical personnel when caring for patients whose sensitivity to pain may vary,” he said.
At the same time, the scientists highlighted that the findings could facilitate new ways to manipulate the body’s natural processes that control pain perception, for example through the design of new drugs that inhibit the melanocortin 4 receptors involved in pain detection. .
Now, scientists are working on new research aimed at elucidating how additional signals derived from the skin regulate the pain and opioid activity. By achieving an in-depth understanding of these pathways, it will be possible to advance in the identification of innovative strategies aimed at modulating pain with different objectives.
Reduced MC4R signaling alters nociceptive thresholds associated with red hair. David E. Fisher, Kathleen C. Robinson et al. Science Advances (2021).DOI:https://doi.org/10.1126/sciadv.abd1310
Photo: Pietra Schwarzler and Unsplash.
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.