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Tuesday, July 03, 2007

More Neuropeptide Y Blogging

More on the amazing work of Zofia Zukowska et al (among other things Zukowska demonstrates how one can overcome alphabetical discrimination. I'm sure she has been last in roll calls all her life and I complain about being filed under W).

After confirming the role of NPY in fat formation in additional studies in genetically engineered mice, the researchers showed in laboratory experiments that NPY induces the growth of immature fat cells, coaxes mature fat cells to get bigger and promotes blood vessels necessary to sustain fat tissue.

The researchers also demonstrated that injecting a substance that blocks NPY prevented mice from accumulating fat -- even if they were stressed and ate a high-fat diet -- and could shrink fat deposits by 40 percent to 50 percent within two weeks.

"It just melts the fat. It's incredible," said Zukowska, noting that the technique could offer an alternative or supplement to liposuction.

On the flip side, when researchers inserted pellets containing NPY under the skin of mice and three monkeys, they were able to stimulate fat growth, suggesting that the approach could replace skin fillers and other cosmetic and reconstructive surgical techniques.

"This has tremendous potential applications for both cosmetic and reconstructive surgery," said Stephen B. Baker, a Georgetown University professor of plastic surgery who helped conduct the research.

Detailed studies of the mice and preliminary findings from the monkeys found no signs of adverse side effects.

"We think we have hit on the natural mechanism that mammals use to grow fat, and reversing that process is the most natural thing," Zukowska said.

"It just has tremendous potential applications," she said. "I have never seen anything like this."

Others cautioned that much more research would be needed to confirm that the same system works in people, and to learn whether blocking or stimulating NPY receptors is safe.

"You might have side effects you wouldn't want, which is always the problem with a substance in the body that does many different things," said Bruce McEwen of Rockefeller University in New York.

McEwen has a good point. If all we worried about was obesity doctors could just prescribe crack. However, I wonder if in this case the multiple effects are useful. I mean imagine something which prevented unsightly fat deposits but had no effect on diabetes or blood cholesterol (can you say liposuction ? I thought you could). This could lead to worse health as people deal with the minor aesthetic problem which would otherwise lead us to eat less junk food and excercize more (or at all in my case). Neuropeptide Y (NPY) is known to affect appetite. The new results show it has an effect on location in the adipose tissue (fat) not just in the brain. An antagonist will have many effects. They might all be good. Stranger things have happened.

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