WORLD
Mouse heart `re-grows when cut`, study shows
Baku, February 26 (AZERTAC). The mice had a large chunk of their heart removed a day after birth, only for the heart to restore itself within three weeks.
Fish and amphibians are known to have the power to re-grow heart tissue, but the study in Science is the first time the process has been seen in mammals.
British experts said understanding the process could help human heart care.
The researchers at the University of Texas Southwestern Medical Center surgically removed what is known as the left ventricular apex of the heart (about 15% of the heart muscle) from mice just a day after birth.
The heart was then quickly seen to regenerate and was fully restored after 21 days. After two months, the organ still appeared to be functioning normally.
But when the same procedure was tested on mice aged one week, the heart failed to regenerate, suggesting this power of self-repair is extremely short-lived in mice.
What our results show are that the new heart muscle cells which repair the amputated region of the heart came from proliferation and migration of pre-existing heart muscle cells," said Professor Eric Olson, who worked on the study.
Many amphibians and fish, most famously the zebrafish, have the ability to renew heart muscle right into adulthood.
This new study suggests mammals too have such capacity for self-repair, if only for a limited time after birth.
Professor Olson believes future research will show humans have a similar capacity, although no experiments involving human heart tissue are currently planned.
The team`s focus is now on looking at ways to "re-awaken" this capacity to self repair in adult mice, with the ultimate ambition to do the same in humans to repair damage sustained during heart attacks.