title: Enteral arginine partially ameliorates parenteral nutrition-induced small intestinal atrophy and stimulates hepatic protein synthesis in neonatal piglets.
abstract: BACKGROUND
  Arginine is an indispensable amino acid in neonates; de novo synthesis of arginine occurs in the small intestine (SI) but is reduced during parenteral nutrition (PN), limiting the arginine available to the mucosa. We assessed the effects of route of intake and dietary concentration of arginine on protein synthesis, superior mesenteric artery (SMA) blood flow, and SI morphology.
  
  
  METHODS
  Piglets (n = 18, 14-17 days old) were given complete PN for 3 days to induce SI atrophy, then switched to 1 of 3 treatments: arginine-free PN plus an intragastric (IG) infusion of high arginine (1.6 g · kg(-1)· d(-1), IG-H Arg) or low arginine (0.6 g · kg(-1)· d(-1), IG-L Arg) or complete high-arginine PN (1.6 g · kg(-1)· d(-1), IV-H Arg).
  
  
  RESULTS
  Enteral arginine, irrespective of amount provided, stimulated hepatic protein synthesis compared with intravenous delivery of arginine (P = .01). SMA blood flow declined for all groups following the initiation of PN. After 48 hours on the test diets, all groups reached low constant levels, but the IV-H group was significantly higher than both IG groups (P < .05). Despite greater blood flow, the SI morphological characteristics in IV-H Arg pigs were not significantly improved over the other groups. IV-H Arg pigs had higher plasma concentrations of indispensable amino acids (tyrosine, isoleucine, and valine) compared with IG-H Arg, despite identical amino acid intakes.
  
  
  CONCLUSIONS
  Intravenous delivery of arginine sustained the best SMA blood flow, whereas even a moderate amount of enteral arginine stimulated liver protein synthesis and maintained SI growth, independent of blood flow.
authors: Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland & Labrador, Canada.
authors: O Chandani
authors: OC
authors: Dinesh
authors: Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland & Labrador, Canada.
authors: M Elaine
authors: ME
authors: Dodge
authors: Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland & Labrador, Canada.
authors: Mark P
authors: MP
authors: Baldwin
authors: Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland & Labrador, Canada.
authors: Robert F
authors: RF
authors: Bertolo
authors: Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland & Labrador, Canada jbrunton@mun.ca.
authors: Janet A
authors: JA
authors: Brunton
mesh_terms: D000601:Amino Acids, Essential / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001120:Arginine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D001284:Atrophy / Q000209:etiology; D004032:Diet; D004750:Enteral Nutrition; D007413:Intestinal Mucosa; D007421:Intestine, Small / Q000098:blood supply / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D017538:Mesenteric Artery, Superior; D009929:Organ Size; D010288:Parenteral Nutrition; D010289:Parenteral Nutrition, Total / Q000009:adverse effects*; D014176:Protein Biosynthesis / Q000187:drug effects*; D012039:Regional Blood Flow; D013552:Swine
chemical_list: D000601:Amino Acids, Essential; D001120:Arginine
keywords: arginine; parenteral nutrition; small intestinal atrophy