Brain Peptide Could be Key to Fighting Obesity and Eating Disorders

Scientists are in hot pursuit of a reliable weight loss pill, and a recent study published in the journal Neuropsychopharmacology shows they might have come one step closer. The study, which was funded in part by the National Institute of Health, showed that rats eat less when they're injected with pituitary adenylate cyclase-activating peptide (PACAP) in a part of the brain called the central amygdala.

New Application for PACAP

While PACAP was already known to affect eating in the hypothalamus, which regulates appetite, the impact in the central amygdala is new knowledge. The amygdala is already known to play a role in emotional eating and fear, so the study may someday lead to ways to control binge eating and other disorders, as well as general obesity. 

The peptide injection didn't affect how many meals the rats ate, but it did cut down the amount of food consumed in each meal. "In addition, we found that PACAP reduced the rate of intake of food. This means that, following administration of PACAP, models were eating more slowly," said researcher Valentina Sabino, assistant professor of pharmacology and psychiatry, and co-director of the Laboratory of Addictive Disorder at Boston University School of Medicine.

The study also found that the PACAP injections only work when the growth hormone brain-derived neurotrophic factor (BDNF) is present. When it was blocked, the rats ate the usual amount of food.

Discovery May Someday Ease Eating Disorders

Researchers expressed optimism about someday applying these findings to human weight loss. "The PACAP system may hypothetically be the target of medications to treat not only obesity but also binge eating, a disease characterized by excessive, uncontrollable consumption of food within brief periods of time,” said study coauthor Pietro Cottone, associate professor of pharmacology and psychiatry and co-director of the Laboratory of Addictive Disorder at Boston University School of Medicine.

That application is still far in the future, but there are still many ways to get help for eating disorders. Current treatment options include therapy, nutritional counseling, behavior modification, mood stabilizers, antidepressant medication, and medical monitoring.