In The News: Promising Appetite Suppressing Hormone Discovered
Tue, 21 Feb. 2012 - 7:48 p.m. MT
Credit: ARA Staff - American Running Association
A hormone that sharply reduces appetite, which researchers at Stanford University discovered last month, caused laboratory mice to eat half as much as usual. All of the mice given the hormone lost weight, and the researchers theorize this may be due to its slowing of food passage through the stomach and small intestine. The hormone, called obestatin, has yet to be tested on humans, but other obesity researchers have speculated that odds are very good the results will hold up in people as well. There is some reason to believe the effect on body weight might be subtle, however. The mice did not lose as much weight as they were expected to. There is also some speculation that the weight lost might not be fat. One limitation of the study is that the hormone was studied only in normal mice, and not in fat ones. Another issue is whether the mice lost weight simply due to a decreased appetite, or whether they were made to feel sick. Results are difficult to interpret because rodents do not vomit. Another hormone, ghrelin, induces appetite—and scientists were surprised to find that both this hormone and obestatin are products of the same gene. The fact that the body utilizes two counteracting hormones to regulate appetite might seem counterintuitive, but it does explain something that formerly puzzled researchers about ghrelin. When scientists created a mouse lacking ghrelin, they expected it to be underweight and lack interest in food. These mice, however, were essentially normal. Scientists now realize that deleting the gene tied to ghrelin also deleted obestatin; the deletion of both the hunger and the fullness signal then had no net effect. Although the new hormone, should it prove effective as an appetite suppressant in humans, would be quite useful in our age of obesity, it would never be available in pill form. The stomach would break down the pill and render it ineffective. An inhaled version of the drug would need to be developed.
(Science, 2005, Vol. 310, No. 5750, pp. 996-999)
(RUNNING & FITNEWS® September/October 2005 • Volume 23, Number 5)