THURSDAY, Feb. 24 (HealthDay News) -- A mouse heart rapidly regenerated itself after researchers removed a portion of the organ a day after birth, scientists report.
With this discovery, the scientists say there is renewed hope that ways can be found to help the human heart heal itself.
"In principle, mechanisms exist in a mammalian heart for regeneration, but they're somehow permanently switched off," said Eric Olson, co-senior author of a paper appearing in the Feb. 25 issue of Science. "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."
"This shows that postnatal mammals can [regenerate their hearts]," said Dr. Stephen Badylak, deputy director of tissue engineering at the McGowan Institute for Regenerative Medicine at the University of Pittsburgh. "That's very important."
Although newts and frogs and various fish, notably the zebra fish, can regenerate their hearts even as adults, mammalian hearts haven't shown that capacity -- although mammalian fetuses have.
"It's been known for a long time that fetuses in different species can regenerate a lot of different body structures, but by the time they're born, they lose that regeneration process," said Badylak, who is also president of the Tissue Engineering and Regenerative Medicine International Society.
For this study, researchers surgically removed about 15 percent of the ventricle in day-old mice.
Within a week, the mice had regenerated the amputated part of the heart, "giving rise to a fully functional heart with no evidence of scar or reduction in cardiac function," said Olson, who is professor and chairman of molecular biology at the University of Texas Southwestern Medical Center in Dallas.
But the regenerative potential disappeared when the mice were se
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