Sep 16, 2008

Health - Hunger horomone can be suppressed

WASHINGTON: An Indian American medical scientist has successfully suppressed levels of 'hunger hormone' ghrelin in pigs, which could pave the way for a lasting solution to obesity in people.

He relied on a minimally invasive mode of vapourising the main vessel carrying blood to the top section or fundus of the stomach. An estimated 90 per cent of the body's ghrelin originates in the fundus, which, without good blood supply, can't synthesise the hormone.

"With gastric artery chemical embolisation, called GACE, there's no major surgery," said Aravind Arepally, clinical director of the Centre for Bio-engineering Innovation, design and associate professor of radiology and surgery at the Johns 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."

Arepally and his team pointed out that for more than a decade, efforts to safely and easily suppress ghrelin 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 bio-medical problem in the country, and a minimally invasive alternative would make an enormous difference in choices and outcomes for obese people," Arepally said.

Arepally and colleagues conducted their study over 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, because of their human-like anatomy and physiology, he said.

Using X-ray for guidance, researchers 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 saline injections in the left gastric arteries of five control pigs, and in the other five, one-time shots 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.

These findings were reported in the Tuesday online edition of Radiology.

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