Scientists at the Southwestern
Medical Center in Texas have reported that during an experiment
they have noted that the heart of a mouse is capable of regeneration even if a small
portion of its heart is removed a day after its birth. With this discovery
scientists hope to find a way to help the human heart heal itself.
Co-senior author of the study, Eric Olson said, "In principle, mechanisms exist in a mammalian heart for regeneration, but they're somehow permanently switched off. Now that we know (that this can happen), at least in principle, we can start to screen for drugs or genes or growth factors that might reawaken these mechanisms in adult hearts."
It is known that frogs and certain fish (zebra fish) can regenerate their cardiac tissues. But mammalian hearts have not shown that capacity. Mammalian fetuses can regenerate but this regeneration process is lost once they are born. During the study scientists surgically removed about 15% of the ventricle in one day-old mice. It was seen that within a week's period the mice regenerated the amputated part of their heart. The heart was fully functional and did not show any evidence of scar formation or reduction in cardiac activity. However this potential to regenerate disappeared once the mice were 7-10days old. Researchers found that the new heart muscle cells are formed from the pre-existing muscle cells. Scientists hope to develop the therapeutic potential of this discovery.