Could the new weapon in the battle of the bulge be a nasal spray? Scientists are looking into a spray containing a naturally-occurring hormone, PYY3-36, which may tell the brain that the belly is full.

In 2002, researchers from Imperial College in London discovered that the gastrointestinal hormone PYY3-36 appears to signal to the brain that the stomach is full. Steve Bloom, a researcher at Hammersmith Hospital and professor at Imperial College, reported it reduced food intake and body weight in rodents, and in a small study in humans. However, 42 scientists from 12 different labs around the world independently tested PYY3-36 in rodents and failed to see the same results, finding no significant effect on food intake or body weight.

But now, a round of tests on rats by researchers at Creighton University School of Medicine and the Omaha Nebraska VA hospital is showing more positive results. “We now, I think, have clearly shown that PYY3-36 is a potent inhibitor of food intake,” says Roger Reidelberger, professor of biomedical science at Creighton University.

In the other studies, scientists used shots—either a placebo or the real thing—to deliver the hormone, causing Bloom and other scientists to suggest that if the rodents weren’t properly adapted to being handled and injected, it may have stressed out the rodents and affected the results. Reidelberger reported in the journal Endocrinology that in the tests he and his team did, the hormone was delivered intravenously, to get a steady flow of lower doses.”By infusing it like we do, over a period of hours, we can maintain the levels, much like what occurs under normal conditions after ingesting a meal,” Reidelberger explains.

More here.