Grant: Master's Award: Canada Graduate Scholarships

Preterm infants commonly require intravenous (i.v.) nutritional support, due to medical issues related to the gastrointestinal tract, or other illnesses associated with prematurity. The transition from i.v. nutritional support to oral feeding can be difficult, as prolonged i.v. feeding impedes intestinal regeneration and growth. Failure to adapt to oral feeding is common, and some infants develop a devastating infection, necrotizing enterocolitis (NEC), which can lead to the loss of some or all of the small intestine. Arginine is an important amino acid that is made in the small intestine of the newborn infant, and deficiency of arginine has been linked to the onset of NEC. Arginine is used to make nitric oxide (NO), which is important for maintaining blood flow to tissues and organs and has immune activity by reducing inflammation. NO production appears to be greater when arginine is supplied as a dipeptide (molecule of two amino acids). Dipeptides are absorbed into the intestine through a transporter, PepT1. In situations of intestinal injury, PepT1 levels are enhanced to facilitate the uptake of peptides. We plan to conduct a study in piglets with i.v-induced intestinal injury. We hypothesize that when arginine is supplied as a dipeptide there will be greater uptake by PepT1 compared to free arginine. Two groups of piglets with intestinal injury will be fed formulas with free arginine or the dipeptide Arg-Gly for one day then will undergo a study to assess intestinal blood flow, rate of NO synthesis and intestinal structure and function. Targeting greater NO production through Arg-Gly supplementation may be a therapeutic strategy to enhance recovery of the injured intestine and prevent the onset of NEC.