title: Dietary protein composition influences abundance of peptide and amino acid transporter messenger ribonucleic acid in the small intestine of 2 lines of broiler chicks.
abstract: This study evaluated the effect of dietary protein composition on mRNA abundance of a peptide transporter (peptide transporter 1, PepT1), amino acid (AA) transporters [Na(+)-independent cationic and zwitterionic AA transporter (b(o,+)AT), excitatory AA transporter 3 (EAAT3), Na(+)-independent cationic and Na(+)-dependent neutral AA transporter 2 (y(+)LAT2), L-type AA transporter 1 (LAT1), and cationic AA transporter 1 (CAT1)], and a digestive enzyme (aminopeptidase N) in 2 lines (A and B) of broilers that differentially express PepT1 mRNA (line B > line A). From d 8 to 15 posthatch, birds were fed 1 of 3 diets. Protein sources included whey protein concentrate, a whey partial hydrolysate (WPH), or a mixture of free AA (AA) identical to the composition of whey. Quantities of mRNA were assayed by real-time PCR in the small intestine of males at d 8, 9, 11, 13, and 15. For all genes except LAT1, abundance of mRNA was greatest in line B birds that consumed the WPH diet (P < 0.006). When mRNA abundance was normalized to beta-actin quantities, this effect disappeared, demonstrating a generalized effect on gene expression in line B birds that consumed the hydrolysate. There was a greater villus height:crypt depth ratio (P < 0.05) in line B birds fed the WPH diet as compared with line A. In conclusion, line B birds, which express greater PepT1, displayed enhanced intestinal mucosal absorptive surface area and differential regulation of PepT1, AA transporters, and aminopeptidase N in response to dietary protein composition.
authors.affiliation: Virginia Polytechnic Institute and State University, Department of Animal and Poultry Sciences, Blacksburg, 24061, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Gilbert
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: D A
authors.initials: DA
authors.lastname: Emmerson
authors.forename: K E
authors.initials: KE
authors.lastname: Webb
authors.forename: E A
authors.initials: EA
authors.lastname: Wong
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics*; D000596:Amino Acids / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D002645:Chickens / Q000235:genetics*; D004044:Dietary Proteins; D004386:Duodenum / Q000502:physiology; D050580:Excitatory Amino Acid Transporter 3 / Q000235:genetics; D007082:Ileum / Q000502:physiology; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000502:physiology*; D007583:Jejunum / Q000502:physiology; D008297:Male; D008892:Milk; D000074011:Peptide Transporter 1; D010455:Peptides / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics*; D027981:Symporters / Q000235:genetics; D050916:TRPV Cation Channels / Q000235:genetics
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D004044:Dietary Proteins; D050580:Excitatory Amino Acid Transporter 3; D000074011:Peptide Transporter 1; D010455:Peptides; D012333:RNA, Messenger; D027981:Symporters; D050916:TRPV Cation Channels