Insulin-Like Protein Points to
New Diabetes Drugs
December 16, 2004
By Megan Rauscher
Japanese investigators have isolated a new compound
produced by fat tissue that shares properties with insulin
and may lead to the development of new diabetes drugs.
They call the protein visfatin.
Visfatin is produced in abdominal visceral fat of both
humans and mice. The blood level of the protein "increases
during the development of obesity," the team reports
in the journal Science, published online Thursday at
the ScienceExpress Web site.
"Surprisingly," Dr. Iichiro Shimomura, from
Osaka University and colleagues write, "visfatin
binds to and activates the insulin receptor."
There are, however, "important differences"
between visfatin and insulin, the team notes. For example,
visfatin levels do not change markedly with fasting
or feeding, as is the case with insulin.
It's known that obesity, and specifically the accumulation
of fat in the abdomen around the visceral organs, is
linked to the development of insulin resistance that
can lead to overt diabetes. Shimomura explained how
visfatin may play into this scenario.
Chronically high levels of visfatin resulting from
visceral fat obesity, he said, "may underlie insulin
resistance by continuously stimulating insulin receptors."
Alternatively, "as visfatin activates insulin
receptor in a different manner from insulin, visfatin
may be useful to treat insulin resistance," the
researcher commented.
Indeed, the researchers found that visfatin displays
beneficial insulin-like effects in mice. High doses
of synthetic visfatin lowered blood glucose levels in
insulin-resistant or insulin-deficient animals.
But as the two authors of a related editorial point
out, much remains to be discovered about how visfatin,
insulin and glucose are related.
Source:www.reuters.com
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