After surgically removing 15 percent of the hearts of newborn mice, researchers at the University of Texas Southwestern Medical Center found that the hearts completely regrew within three weeks.
Not only that, the hearts both looked and functioned normally, Enzo Porello and his team said.
However, at the 1-week-old marker, the mice lost this regenerative ability.
Scientists have long known that some fish and amphibians are able to regrow damaged heart tissue – but that adult mammals are not able to.
This has serious implications for humans, because it means the heart cannot rebuild cardiac muscle and repair itself after a heart attack.
The researchers hope this finding may indicate that there are indeed methods to help the human heart regenerate. Understanding the process of heart regrowth in human mice may lead to new therapies.
“If we can understand the mechanisms whereby cardiomyocytes [heart muscle cells] retain or regain the ability to proliferate, we may be able to harness that potential to regrow healthy heart muscle,” said Dr. Eduardo Marbán, director of the Cedars-Sinai Heart Institute.
It is worth noting, Marban said, that there have been cases of newborn babies who suffer heart attacks and go on to recover completely.
The study was published in the journal Science.