Mouse heart 're-grows when cut', study shows

Scientists in the United States have found newborn mice can re-grow their own hearts.

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.

The belief is that heart cells within the mouse have a narrow window after birth within which they can continue to replicate and repair. Subsequent tests suggested that these repair cells were coming from within the heart muscle. ...

via BBC News - Mouse heart 're-grows when cut', study shows.