http://www.eurekalert.org/pub_releases/2008-09/jhmi-jhr091408.php

Johns Hopkins researchers suppress 'hunger hormone'

New minimally invasive method tested in pigs yields result as good as
bariatric surgery

Johns Hopkins scientists report success in significantly suppressing levels
of the "hunger hormone" ghrelin in pigs using a minimally invasive means of
chemically vaporizing the main vessel carrying blood to the top section, or
fundus, of the stomach. An estimated 90 percent of the body's ghrelin
originates in the fundus, which can't make the hormone without a good blood
supply.

"With gastric artery chemical embolization, called GACE, there's no major
surgery," says Aravind Arepally, M.D., clinical director of the Center for
Bioengineering Innovation and Design and associate professor of radiology
and surgery at the John Hopkins University School of Medicine. "In our study
in pigs, this procedure produced an effect similar to bariatric surgery by
suppressing ghrelin levels and subsequently lowering appetite."

Reporting on the research in the September 16 online edition of Radiology,
Arepally and his team note that for more than a decade, efforts to safely
and easily suppress grehlin have met with very limited success.

Bariatric surgery - involving the removal, reconstruction or bypass of part
of the stomach or bowel - is effective in suppressing appetite and leading
to significant weight loss, but carries substantial surgical risks and
complications. "Obesity is the biggest biomedical problem in the country,
and a minimally invasive alternative would make an enormous difference in
choices and outcomes for obese people," Arepally says.

Arepally and colleagues conducted their study over the course of four weeks
using 10 healthy, growing pigs; after an overnight fast, the animals were
weighed and blood samples were taken to measure baseline ghrelin levels.
Pigs were the best option, he says, because of their human-like anatomy and
physiology.

Using X-ray for guidance, members of the research team threaded a thin tube
up through a large blood vessel near the pigs' groins and then into the
gastric arteries supplying blood to the stomachs. There, they administered
one-time injections of saline in the left gastric arteries of five control
pigs, and in the other five, one-time injections of sodium morrhuate, a
chemical that destroys the blood vessels.

The team then sampled the pigs' blood for one month to monitor ghrelin
values. The levels of the hormone in GACE-treated pigs were suppressed up to
60 percent from baseline.

"Appetite is complicated because it involves both the mind and body,"
Arepally says. "Ghrelin fluctuates throughout the day, responding to all
kinds of emotional and physiological scenarios. But even if the brain says
"produce more ghrelin," GACE physically prevents the stomach from making the
hunger hormone."