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Drugs Stimulate Growth of New
Blood Vessels By Mimicking Growth Factor
New research indicates that besides lowering levels of harmful
cholesterol, the drugs may also promote the growth of new
blood vessels, which may not necessarily be such a great thing.
Although this effect may help to prevent heart attacks and
other forms of heart disease, it may have the potential to
promote cancer as well.
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Tests in human cell samples and in rabbits, show that
the cholesterol-lowering drug simvastatin (Zocor) seems
to activate a pathway through which cells communicate
and act very similar to a naturally-occurring growth factor,
according to Dr. Kenneth Walsh, of Tufts University School
of Medicine in Boston, Massachusetts.
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Researchers suspect that the drug interacts with a molecule
called protein kinase Akt/PKB, which helps regulate blood
vessel development properly.
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Simvastatin produced similar effects on the growth of
new blood vessels, a process called angiogenesis, as does
vascular endothelial growth factor (VEGF), a substance
essential for healthy blood vessels, according to Dr.
Walsh. "The same pathway is being activated by statins
as VEGF," he said.
But if statins do promote angiogenesis, the effects may not
always be helpful, Dr. Michael Simons, of Beth Israel Deaconess
Medical Center in Boston points out in an editorial that accompanies
the study.
For example, statins might increase the growth of blood vessels
in cancerous tumors, Simons notes. However, even though statins
are some of the most widely used prescription drugs, these
and other potential harmful effects have not been reported,
which calls into question their vessel-promoting abilities,
Dr. Simons adds.
Nature Medicine September,
2000;6:965-966, 1004-1010.
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