A Love Hormone Has Heart-healing Properties

February 14, 2023

Heart diseases like myocardial infarction remain the leading cause of death globally. The human heart has limited healing properties. However, studies show that some living beings, like zebrafish, have incredible organ regenerative properties. It can regenerate the heart even if one-third of it has been lost. A new study shows that heart regeneration in zebrafish occurs due to love hormone or oxytocin, which stimulates stem cells, converting them to Epicardium-derived Progenitor Cells (EpiPCs), thus leading to heart healing.

Heart attack still remains the leading cause of death in the US and globally. In heart disease, blood vessels supplying blood to the heart muscles get blocked, causing infarction and death of local heart muscles. If blocked arteries are not opened quickly with medications or other means, irreversible death of heart muscle tissues occurs, causing heart failure and death.

doctors mainly try to open blocked arteries, but there is no way of regenerating dead tissues. If doctors could find a way to revive heart muscles and promote their regrowth, many lives could be saved. However, regenerative medicine is not just limited to hearts. Researchers are exploring various ways to help people recover from a variety of illnesses and injuries, such as diabetic neuropathy pain and sciatica nerve pain. Here it is vital to understand that in humans, all organs can grow or regenerate to a degree. But, this ability to regenerate or heal is quite limited for most organs. Therefore, if significant damage has occurred, it causes organ failure.

However, researchers know that some living beings can regenerate their organs more significantly than humans. One such example is zebrafish. It has an amazing ability to regenerate its various organs like the liver, heart, and so on. For example, it can regenerate the heart, even if one-third has been lost due to some injury. Therefore, researchers decided to study the underlying mechanism. To their amazement, they found that zebra fish starts secreting oxytocin, a love hormone also present in humans, in response to heart injury. Moreover, after heart injury, oxytocin levels in zebrafish increase by more than 20 times.

This increase in oxytocin levels appears to stimulate stem cells present in the outer layer of the heart, that is, in the epicardium. Under the influence of oxytocin, stem cells migrate from the epicardium to the myocardium (muscular layer of the heart), and there they are transformed into cardiomyocytes, and the healing process begins.

In humans, oxytocin plays a role in many body functions. It is released after sex and is associated with pleasure and bonding. It also regulates ejaculation, lactation, and many other body functions. In humans, oxytocin has wide-ranging effects, affecting various body functions and influencing the brain’s working.

Here it is vital to understand that stem cells are present in almost every tissue in the human body, but science still does not know how to regulate them. Therefore, researchers are looking for ways to control stem cells present in various body parts, as this will allow them to regenerate organs and promote healing processes.

Researchers at Michigan State University not only tested oxytocin but also tested 15 other neuropeptides. However, they found that such an ability to promote healing processes was only related to oxytocin1. It appears that oxytocin can reprogram stem cells into Epicardium-derived Progenitor Cells (EpiPCs), which can then carry heart regeneration. However, in humans, EpiPCs activity is quite low, and thus the very limited ability of the heart to regenerate itself.

Next, researchers tested if oxytocin could have similar effects on human heart tissues. Amazingly, in an in vitro study, they found that in humans, also oxytocin stimulates Pluripotent Stem Cells (hIPSCs) to become EpiPCs. It appears that this mechanism plays a vital role in heart healing after myocardial infarction. However, if oxytocin is knocked out, healing processes also stop.

These findings are interesting as oxytocin is a readily available hormone for humans. Therefore, in the future, there is a need to find out if giving oxytocin to myocardial infarction patients can really help. Since oxytocin is approved for clinical use in other health conditions, testing it in heart patients would be relatively easier. If researchers can prove that it helps in clinical settings, we are likely to see its widespread use in heart patients in the near future.

By Gurpreet Singh Padda, MD, MBA, MHP