Endocrine Abstracts

Exogenous administration of the gut hormone peptide YY3-36 (PYY3-36) reduces food intake in obese humans and rodents. New lines of evidence support a role for endogenous PYY3-36 in regulating energy homeostasis. The NPY-Y2 receptor mediates the anorectic actions of PYY3-36 with rodent studies implicating the hypothalamus, vagus and brainstem as key target sites. Functional imaging in humans has confirmed that PYY3-36 activates brainstem and hypothalamic regions. The greatest effects, however, were observed within the orbitofrontal cortex, a brain region involved in reward processing. Further evidence for a hedonic role for PYY3-36 is supported by rodent studies showing that PYY3-36 decreases the motivation to seek high-fat food. These emerging hedonic effects of PYY3-36 together with the weight-reducing effects observed in obese rodents suggest that targeting the peptide YY system may offer a therapeutic strategy for obesity.