For folks who have long wished that losing weight was just a matter of popping a pill, Johns Hopkins scientists report they are one step closer to finding a way to control appetite.Injecting an enzyme that blocks fatty acid synthase (FAS) into the brains of mice acts on certain brain chemicals and results in decreased appetite, thereby reducing body weight, they report."We have been working on this control of food intake,” explained lead researcher M. Daniel Lane, a distinguished service professor in the Department of Biological Chemistry. “Five years ago, we found a compound that we call C75 blocks food intake."It works like this, Lane said: C75 blocks FAS and, when FAS is blocked, the amount of another compound, called malonyl-CoA, increases. That rise in malonyl-CoA suppresses some of the brain chemicals that increase appetite, he explained. In addition, the amount of other chemicals that suppress appetite is also increased.In this latest study, Lane and his colleagues found C75 works by blocking the production of a compound called ghrelin, an appetite stimulant. Ghrelin is produced in the brain and the stomach, Lane noted.To test their theory, Lane’s team injected ghrelin into the mice. As expected, the ghrelin injection reversed the effect of C75."This brings us closer to the site where C75 acts,” Lane said. “Now, we have to find out how malonyl-CoA prevents the secretion of ghrelin."Lane’s latest findings appear in this week’s issue of the Proceedings of the National Academy of Sciences.
