Peptide YY(3-36) inhibits gastric emptying and produces acute reductions in food intake in rhesus monkeys

Peptide YY_3-36 [PYY(3-36)], a gastrointestinal peptide that is released into the circulation in response to ingesting a meal, has recently been suggested to play a role in controlling food intake. PYY(3-36) has been reported to inhibit food intake following peripheral administration in rodents and in human subjects. To more fully characterize the potential feeding actions of PYY(3-36), we examined the ability of a dose range of PYY(3-36) (0.3-3.0 nmol/kg) to affect liquid gastric emptying and daily 6-h food intake in male rhesus monkeys. Intramuscular PYY(3-36) produced a dose-related inhibition of saline gastric emptying that was maximal at a dose of 3 nmol/kg. Intramuscular PYY(3-36) administered before daily 6-h food access produced significant feeding reductions at doses of 1 and 3 nmol/kg. Analyses of the patterns of food intake across the 6-h period of food access revealed that PYY(3-36) increased the latency to the first meal and reduced average meal size without altering meal number. Although single doses of PYY(3-36) reduced intake, a suppressive effect on food intake was not sustained over multiple administrations across successive days. Together, these data suggest that PYY(3-36) has the ability to reduce food intake in acute test situations in nonhuman primates. Whether this is a physiological action of the endogenous peptide remains to be determined.