Peptide YY (3-36) Represents a High Percentage of Total PYY Immunoreactivity in Preterm and Full-Term Infants and Correlates Independently With Markers of Adiposity and Serum Ghrelin Concentrations

Abstract

ABSTRACT:The gut hormone peptide YY 3-36 ] has been suggested to posses anorexigenic actions in animals and human adults. However, its circulating concentrations and function have not been studied in neonates. Serum concentrations of PYY (3-36) were determined by RIA (RIA) in 62 healthy preterm infants [mean(SD) gestational age, 32.0(2.1) weeks; postnatal age, 40.9(14.8 d)] and 15 healthy fullterm infants of comparable postnatal age and gender. The correlations between PYY (3-36) levels and anthropometric characteristics, food intake, growth rates and circulating concentrations of total PYY, ghrelin, leptin, insulin and adiponectin were examined. Mean (SD) PYY (3-36) concentrations were higher in preterm [543.7(157.6) ng/L) than full term infants [350.9(114.1) ng/L; p Ͻ 0.001) and accounted for 48% and 42% of total PYY basal plasma immunoreactivity in preterm and full term infants, respectively. In multiple regression analysis, concentrations correlated negatively with the infants' BMI and positively with serum ghrelin concentrations, but not with caloric intake, weight gain or concentrations of any other hormone studied. In conclusion, PYY (3-36) represents almost half of total PYY immunoreactivity in neonates. It's correlations with ghrelin and BMI suggest a role of this peptide in the regulation of energy homeostasis; however, its specific functions and physiologic significance in neonates remain to be elucidated. ] is one of the two major molecular forms of the gut peptide YY, the other isoform being PYY (1-36) (1). Both isoforms, in addition to exerting secretory and motor activities throughout the gut (2,3), are involved in the central regulation of food intake and energy balance. Both peptides have an anorexigenic effect through a Y2 receptor-mediated mechanism at the level of hypothalamus, whereas PYY (1-36) also possesses orexigenic action by acting at central Y1 receptors (3,4). PYY (3-36) is more potent than PYY (1-36) in several effects, such as decrease of food intake and inhibition of gastric emptying (3).In adults, PYY (3-36) accounts for 37% and 54% of total PYY immunoreactivity in basal and postprandial plasma, respectively (1). However, circulating levels of PYY (3-36)have not been measured in neonates so far. The aim of the present study was to determine the circulating concentrations of PYY (3-36) in preterm and full term infants and to examine their possible associations with the infants' size, caloric intake, weight gain and the serum concentrations of total PYY or other hormones implicated in the regulation of metabolism, such as ghrelin, leptin, insulin and adiponectin (5,6). METHODSStudy population and protocol. Sixty-two preterm [mean (SD) gestational age, 32.0 (2.1) weeks; birth weight, 1542 (275) g; males, 28] and 15 healthy full term infants [gestational age, 39.0 (1.0) weeks; birth weight, 3200 (498) g; males, 6] who served as the reference group were studied. Full term infants had similar gender distribution to that of preterm infants. Gestational age was estimated from the last ...

Early growth and postprandial appetite regulatory hormone responses

“…An epidemiological study has supported this by showing that rapid weight gain in infancy is associated with a higher fasting concentration of ghrelin, reflecting alterations in the appetite regulatory system ( 12 ) . The present results are also in accordance with previous studies of young children which showed that infants who were born with a low birth weight ( 13 ) or born preterm ( 13 , 28 , 29 ) had elevated levels of fasting PYY, reflecting greater satiety. The results from previous studies in which the association between birth weight and fasting levels of ghrelin has been investigated are conflicting, showing no differences ( 14 , 16 ) , decreased ( 13 ) or even elevated ( 15 , 17 ) ghrelin levels among children born with a low birth weight compared with controls.…”

Elevated circulating ghrelin, but not peptide YY(3-36) levels, in term neonates with infection

“…The minimum sample size of the study was calculated using our previous report of circulating ghrelin and PYY concentrations in healthy full-term infants [25]. Assuming an α risk of 0.05, a power of 0.80, and a bilateral test, it was estimated that approximately 10 neonates was the minimum number of infants needed in each group to detect a significant difference of one SD in mean ghrelin or PYY levels between infected and healthy infants.…”

Ενδομήτρια Υπολειπόμενη Αύξηση Και Ανοσολογικοί Παράγοντες Του Γαστρεντερικού

“…Τα άνω και κάτω όρια του θηκογράμματος αντιπροσωπεύουν το εύρος τιμών. Η GLP-1 ανιχνεύεται στο αίμα του ανθρώπινου ομφάλιου λώρου στη γέννηση (396).…”