Dalshini Kirupananthan - September 28, 2020

Role of intestinal peptide transporter 1 (PepT1) in maintaining health in neonatal piglets

Peptide transporter 1 (PepT1) is a proton-coupled oligopeptide transporter that is mainly expressed in the apical membrane of the small intestine. PepT1 is responsible for the transport of tri/di-peptides and peptidomimetic drugs. The PepT1 transporter not only maintains protein nutrition but recently it was identified that it also influences the secretion of peptide hormones from the enteroendocrine cells which may affect appetite regulation and glucose homeostasis. The activity of PepT1 is preserved during intestinal stress or injury, for instance, during the use of parenteral nutrition (PN), whereas free amino acid transporters decline. Premature infants often rely on PN due to medical complications related to prematurity. However, prolonged PN leads to gut atrophy, weakened gut barrier function, and a higher risk of intestinal infections; therefore, enhanced nutrient uptake during enteral re-feeding is important to facilitate rapid recovery. These same gastrointestinal concerns were observed in sow-reared piglets during the weaning process, thus affecting the nutrient status of the animal. Our research utilizes Yucatan miniature piglets as a human infant model. In this presentation, work will be discussed related to 1) the effect of PepT1 mediated lysyl-lysine absorption on L-arginine transport in a healthy neonatal small intestine 2) the bioavailability of lysine when delivered as a dipeptide in a PN-induced atrophied gut and, 3) the influence of PepT1 activation on gut hormone secretion and glucose homeostasis.