Enhancement of feeding suppression by PYY(3-36) in rats with area postrema ablations

We investigated suppression of food intake by intraperitoneal (IP) injections of peptide YY(3-36) (PYY(3-36)) (24, 60, or 150 microg/kg) in rats with ablations of the area postrema (APX) and in controls with sham ablations. In controls, PYY(3-36)-induced suppression was modest and short-lived, averaging 20% at most and persisting less than 6h. The highest dose tested (150 microg/kg) was even less effective than were the two lesser doses after 3h. APX did not diminish the potency of these effects of PYY(3-36). In fact, the magnitude of suppression produced by the greatest dose of PYY(3-36) in APX rats was significantly greater than in controls and PYY(3-36)-induced suppression was still present at 24h.