Oxytocin is called the ‘love hormone’ for many reasons. Its levels usually increase when we hug, have sex or an orgasm. It is also the one that is responsible for causing contractions during childbirth and promoting lactation. According to a study published two years ago in Frontiers in Psychology , this hormone also helps protect the cardiovascular system from injury by reducing blood pressure, inflammation, and the spread of free radicals, a reactive byproduct of cellular metabolism . A new study has discovered another benefit of the ‘love hormone’ and that is that it could help repair heart tissue that is damaged after suffering a heart attack.
The research has been carried out with zebrafish, an animal that is capable of repairing its heart after suffering a heart attack, but also with human cells. In the case of zebrafish, oxytocin helps the heart replace injured and dead cardiomyocytes. Cardiomyocytes are the muscle cells that drive heart contractions and are damaged if a heart attack occurs. As for human cells, the first results suggest that oxytocin has similar effects in people, if it is administered at the right time and in the right dose.
The heart has a very limited ability to repair or replace tissue that has been damaged or died. Several studies suggest that, after an injury, such as a heart attack, a group of cells found in the epicardium, which is the outermost membrane of the heart, acquires a new identity. These cells travel to the layer of heart tissue where the muscles are located and develop into stem-like cells, which can then develop into various types of heart cells, including cardiomyocytes.
This process has been studied mainly in animals and there are indications that it may occur in adult humans. However, in the latter case, the process would take place very inefficiently, since very few cells would cause significant tissue repair after an infarction. According to the authors, by somehow encouraging more epicardial cells to transform into cardiomyocytes , scientists could help our hearts rebuild after injury.
The researchers exposed human cells to oxytocin in the laboratory. They also tested 14 other hormones produced by the brain, but none triggered the desired effect, that is, reaching a state similar to that of stem cells to generate new cardiomyocytes.
The team then went on to experiment with the zebrafish known, in addition to being transparent, for being able to regenerate tissues in its body, including the heart, brain and bones. The researchers found that within three days of heart injury, the fish’s brains began to produce oxytocin in large amounts, up to 20 times more than they did before the damage occurred. What happened was that the hormone traveled from the brain to the heart, connected to its receptors and started the process of transforming the epicardial cells into new cardiomyocytes .
These experiments are still preliminary, but they provide the first indications that oxytocin may be useful in repairing heart tissue after injury . In the future, treatments, such as drugs containing oxytocin or molecules that can connect to hormone receptors, could be developed to improve the recovery of people who have suffered a heart attack and even reduce the risk of future heart failure. cardiac.
“The next thing we need to do is study oxytocin in humans after cardiac injury,” lead author Aitor Aguirre, an assistant professor in the Department of Biomedical Engineering at Michigan State University, said in the release. “Overall, preclinical animal and human clinical trials are needed to move forward.”
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Referencia: Wasserman, A., Huang, A. et. al. Oxytocin promotes epicardial cell activation and heart regeneration after cardiac injury. Frontiers in Cell and Developmental Biology. 2022. DOI: https://doi.org/10.3389/fcell.2022.985298
