WE HAVE been underestimating our hearts. For decades, it was thought the heart was unable to repair itself. Now researchers have shown that mammalian hearts contain stem cells which can produce new cardiac muscle cells as older ones die off.
鈥淭his is the unequivocal demonstration that the heart is a self-renewing organ,鈥� says Piero Anversa of New York Medical College in Valhalla. Anversa鈥檚 team had already identified cells in the human heart that look like stem cells, and proof came from a battery of tests performed on similar cells taken from the hearts of rats. When injected into the rats鈥� damaged hearts, the cells turned into new heart tissue (Cell, vol 114, p 763).