Cardiac muscle cells are always innovative in adults

A group of Swedish researchers have discovered the ability of adult heart muscle cells to innovate.

In general, after birth, the human heart is considered as a part of the body in which muscle cells cannot be divided. However, the team, led by Dr. Jonas Frisen of the Karolinska Institute, Stockholm, Sweden, proved that it was wrong.

Indeed, after studying the healthy hearts of dead people, researchers have shown that cardiac muscle cells (cardiomyocytes) are always renewed.

The team took advantage of the consequences of nuclear tests, conducted in the air from the mid-1950s to 1963.

These nuclear tests have resulted in CO air, in which C belongs to carbon-14.

Yet, CO ₂ in the air is used by plants to produce organic matter, which is then consumed by animals and humans.

Since the concentration of carbon-14 in the air has decreased steadily since 1963, the concentration of carbon-14 in the air has decreased steadily since 1963, so the concentration of carbon-14 is present in the DNA of one's cells to allow the determine the birth date of the cells.

And when compared to the birth month of a person, researchers can determine if these cells are more likely to appear.

This method is more reliable than classical methods, such as DNA marking by injecting a dye into the cell.

Jonas Frisen's team improved his technique in 2005 to study occipital cortex, which showed that neurons were not renewed in this area of ​​the cerebral cortex. Cardiac muscle cells (cardiomyocytes), which make up 20% of the heart's cells, seem to change slowly, with a reduced rate of time.

The rate of renewed cells was 1% at age 20 and 0.45% at 75 years of age. Researchers calculate that by the end of life nearly half of heart muscle cells have been changed.