title: Effect of minimal enteral feeding on splanchnic uptake of leucine in the postabsorptive state in preterm infants.
abstract: We conducted a controlled, randomized trial to study the effect of minimal enteral feeding on leucine uptake by splanchnic tissues, as an indicator of maturation of these tissues, in preterm infants in the first week of life. Within a few hours after birth, while receiving only glucose, a primed constant infusion of [1-(13)C]-leucine was started and continued for 5 h via the nasogastric tube, whereas 5,5,5 D3-leucine was infused intravenously (for both tracers, priming dose 2 mg/kg, continuous infusion 2 mg/kg/h). Patients were thereafter randomized to receive solely parenteral nutrition (C), parenteral nutrition and 20 mL breast milk/kg/d (BM), or parenteral nutrition and 20 mL formula/kg/d (F). On d 7, the measurements were repeated, after discontinuing the oral intake for 5 h. Fourteen infants were included in group C, 12 in group BM, and 12 in group F. There was no difference in energy intake or nitrogen balance at any time. On d 1, plasma enrichment for the nasogastric tracer was lower than for the intravenous tracer for all three groups, both for leucine and for alpha-keto-isocaproic acid. On d 7, the enrichment for leucine and alpha-keto-isocaproic acid for the nasogastric tracer was lower than for the intravenous tracer for the groups BM and F (BM: 3.65 +/- 1.20 nasogastric versus 4.64 +/- 0.64 i.v.; F: 4.37 +/- 1.14 nasogastric versus 5.21 +/- 0.9 i.v.). In the control group, there was no difference between tracers. The lower plasma enrichment for the nasogastric tracer compared with the intravenous tracer suggests uptake of leucine by the splanchnic tissues. We conclude that minimal enteral feeding--even in low volumes of 20 mL/kg/d--increases the leucine uptake by the splanchnic tissue. We speculate that this reflects a higher protein synthesis of splanchnic tissues in the groups receiving enteral nutrition.
authors.affiliation: Neonatology Unit, La Paz University Hospital, Autónoma University of Madrid, Madrid, Spain. PIPAON@santandersupernet.com
authors.forename: Miguel
authors.initials: M
authors.lastname: Sáenz de Pipaón
authors.forename: Ron H T
authors.initials: RH
authors.lastname: VanBeek
authors.forename: José
authors.initials: J
authors.lastname: Quero
authors.forename: Jesús
authors.initials: J
authors.lastname: Pérez
authors.forename: Darcos J L
authors.initials: DJ
authors.lastname: Wattimena
authors.forename: Pieter J J
authors.initials: PJ
authors.lastname: Sauer
mesh_terms: D002247:Carbon Isotopes / Q000097:blood / Q000378:metabolism; D004064:Digestive System / Q000098:blood supply / Q000378:metabolism*; D002149:Energy Intake / Q000502:physiology; D004750:Enteral Nutrition / Q000379:methods*; D005260:Female; D006801:Humans; D007225:Infant Food; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D019102:Infant, Very Low Birth Weight / Q000378:metabolism; D007263:Infusions, Parenteral / Q000379:methods; D007651:Keto Acids / Q000097:blood / Q000378:metabolism / Q000652:urine; D007930:Leucine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008297:Male; D010288:Parenteral Nutrition / Q000379:methods; D013152:Splanchnic Circulation / Q000502:physiology
chemical_list: D002247:Carbon Isotopes; D007651:Keto Acids; C013082:alpha-ketoisocaproic acid; D007930:Leucine