It

acts as a primary incretin, facilitating glucose-stimulated insulin release

from the pancreas.

Its

circulating levels are significantly elevated in obese individuals,

contributing to "satiety resistance."

It

is found in highest concentrations in the duodenum and jejunum to provide

early-phase meal termination signals.

It

is secreted in the active form PYY 3-36 and acts specifically via Y2 receptors

located only on orexigenic NPY/AgRP neurons in the ARC.