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

Abstract

inhibits gastric emptying and produces acute reductions in food intake in rhesus monkeys. Am J Physiol Regul Integr Comp Physiol 288: R384 -R388, 2005. First published September 23, 2004 doi:10.1152/ ajpregu.00535.2004], 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. satiety; meal patterns; gut peptides CONSUMED NUTRIENTS EXCITE the release of a variety of gastrointestinal peptides that serve as feedback signals for coordinating nutrient movement through the gastrointestinal tract, absorption, and metabolism. Different peptides have different sites and patterns of release. Roles for some of those peptides in the controls of food intake have been proposed and/or documented.Recently, peptide YY 3-36 ] has been demonstrated to reduce food intake in rodents and humans. Batterham and colleagues (4) reported significant suppression of food intake in mice and rats in response to peripheral bolus PYY(3-36) administration and significant decreases in food intake in human subjects in response to infusions. An action of peripheral PYY(3-36) through arcuate nucleus Y2 receptors was proposed. The Y2 receptor is a presynaptic inhibitory receptor, and PYY(3-36) has been demonstrated to have relative specificity for this neuropeptide Y (NPY) receptor subtype (13). Consistent with this proposal, PYY(3-36) was shown to inhibit food intake when injected into the arcuate nucleus in intact, but not in Y2 Ϫ/Ϫ , mice, and PYY(3-36) increased activity in proopiomelanocortin (POMC) neurons through decreasing the frequency of inhibitory postsynaptic currents, indicative of a decrease in GABA release. Because arcuate NPY neurons exert a tonic GABAergic inhibitory influence on arcuate POMC neurons, this action of PYY(3-36) was interpreted to support ...

Daily, intermittent intravenous infusion of peptide YY(3-36) reduces daily food intake and adiposity in rats

“…Our finding that chronic PYY(3-36) administration increased gut contents is consistent with prior studies (9,24,29,35) demonstrating that acute systemic administration of PYY and/or PYY slows gastric emptying and intestinal transit. Factors that promote gastric distention by inhibiting gastric emptying can reduce food intake by decreasing meal size (28,32,33).…”

“…PYY has also been reported to exhibit a short functional life when administered by subcutaneous or intraperitoneal injection to mice (36). This likely explains why many laboratories have failed to demonstrate that one or two systemic injections of PYY per day can reduce daily food intake and body weight gain in rodents (39) and monkeys (29).…”

Gut peptides in the control of food intake

“…Bolus doses or slow intravenous infusions have been shown to affect food intake by reducing the size of multiple meals and increasing the satiety ratio (length of the post-meal interval/amount consumed). 31,32 Both peripheral and central sites of action for PYY for inhibiting food intake have been proposed. Subdiaphragmatic vagotomy significantly reduced the feeding inhibition produced by a relatively small dose of PYY .…”

Impact of nutrition on canine behaviour: current status and possible mechanisms

“…A decrease in postprandial gastric-emptying rate will, consequently, prolong gastric distension and gastric signals of satiation 137 -139 . This mechanism was studied by Moran et al 141 in rhesus monkeys where intramuscular injections of PYY reduced gastric emptying and resulted in a decrease in food intake. In addition, there are indications that PYY in the brain reduces appetite in humans 142 , although this is still a subject for debate 143 .…”