255 Leucine Supplementation During Continuous Feeding Enhances Lean Growth in a Preterm Piglet Model

Abstract Extrauterine growth restriction is a common complication of preterm birth and associated with reduced lean long-term morbidities. We previously showed that intermittent pulses leucine during continuous orogastric feeding increases mTORC1 signaling to protein synthesis in skeletal muscle neonatal pigs born at term. The objective this study was determine the extent which would promote by enhancing piglet model. Pigs delivered cesarean section 105 d gestation were continuously fed energy balanced milk-replacer diet [195 kcal ME 13.5 g (kg body weight; BW)-1·d-1)]. (n=11-12) randomly assigned Leucine (LEU) or Alanine (ALA, isonitrogenous control) groups treatments administered as pulse (1.6 mmol·kg BW-1·h-1) for 1 h every 4 21 d. Body composition determined DXA indices amino acid activation postprandially, 60 min after initiation last pulse. LEU had 10% greater average daily gain (ADG) (P < 0.05) than ALA pigs. Total mass tended be (+13%; P 0.06) compared ALA, longissimus dorsi weight 17% heavier (P=0.01). Indices activation, i.e., phosphorylation S6K1 4EBP1 abundance eIF4E-eIF4G complex, increased gastrocnemius 0.05). These results show supplementation enhances mTORC1-activated translation leading an increase Research supported NIH USDA.