|
Heart-Cells
Discovery Gives Hope
Challenging
decades of medical dogma, researchers have discovered that damaged
hearts can repair themselves by growing brand-new muscle cells.
With this
discovery, researchers hope to eventually find ways to boost the
heart's ability to mend itself after a heart attack or heart failure.
``The recognition
that this mechanism exists and, in the future, the ability to
recruit this mechanism, opens up entirely new prospects for novel
kinds of therapy for heart attacks,'' said Dr. Eduardo Marban
of Johns Hopkins University, chairman of the American Heart Association's
council on basic cardiovascular sciences.
Until now,
experts had assumed that the heart - unlike other body parts,
such as skin and bone - could not form new heart cells. It was
thought that once the heart was damaged, the damage was irreversible.
``The bottom
line: We didn't know before. Now we know that heart cells divide.
It's obviously highly significant,'' said David Finkelstein of
the National Institute on Aging, which helped fund the research.
``If one could find a way to turn on this division, it would be
very important.''
For example,
Marban said, heart attack patients in a matter of just a few years
might routinely be given injections of their own laboratory-grown
stem cells to stimulate the growth of new heart muscle.
The researchers
examined 13 hearts after fatal heart attacks and found a significant
amount of new cardiac muscle being formed in two areas of the
heart. Their findings are reported in Thursday's New England Journal
of Medicine.
``This is
probably the most compelling demonstration that heart muscle cells
can regenerate and therefore repair damage,'' said Dr. Piero Anversa,
who conducted the research at New York Medical College in Valhalla,
N.Y.
The damaged
hearts were from patients who had died four to 12 days after suffering
a heart attack. During a heart attack, blockage of a coronary
artery cuts off the blood supply to the heart, killing off part
of the heart muscle. The damaged hearts were compared with 10
hearts from people who died from injuries or other ailments.
The researchers
focused on two areas of the heart - one next to the damaged portion
and one more remote. They checked for evidence of cell division
by looking for a protein present when cells are dividing. Compared
with the normal hearts, the number of multiplying muscle cells
was 70 times higher next to the damage and 24 times higher in
the remote area.
``So the heart
is not so unusual like everybody believed, and the dogma has no
basis to exist,'' Anversa said.
He said the
next step is to identify the dividing cells and to find ways to
target the damaged area of the heart for new cell growth.
Anversa said
the source of the new growth could be existing heart muscle cells
or a primitive cell - called a stem cell - in the heart. He noted
that the brain was once thought to lack stem cells and the ability
to regenerate, but that is no longer true.
``We believe
in the heart the same phenomenon is occurring, although we still
have to prove it unequivocally,'' he said.
On
the Net:
New
England Journal of Medicine: http://content.nejm.org
American Heart Association: http://www.americanheart.org
National Heart, Lung and Blood Institute: http://www.nhlbi.nih.gov
National Institute on Aging: http://www.nih.gov/nia/
Reference
Source 102
For more information on how to prevent other diseases, use
PreventDisease.com's "Quick
Prevention Resources".
|