title: Supplementation with branched-chain amino acids to a low-protein diet regulates intestinal expression of amino acid and peptide transporters in weanling pigs.
abstract: This study determined the effects of dietary branched-chain amino acids (AA) (BCAA) on growth performance, expression of jejunal AA and peptide transporters, and the colonic microflora of weanling piglets fed a low-protein (LP) diet. One hundred and eight Large White × Landrace × Duroc piglets (weaned at 28 days of age) were fed a normal protein diet (NP, 20.9 % crude protein), an LP diet (LP, 17.1 % crude protein), or an LP diet supplemented with BCAA (LP + BCAA, 17.9 % crude protein) for 14 days. Dietary protein restriction reduced piglet growth performance and small-intestinal villous height, which were restored by BCAA supplementation to the LP diet to values for the NP diet. Serum concentrations of BCAA were reduced in piglets fed the LP diet while those in piglets fed the LP + BCAA diet were similar to values for the NP group. mRNA levels for Na(+)-neutral AA exchanger-2, cationic AA transporter-1, b(0,+) AA transporter, and 4F2 heavy chain were more abundant in piglets fed the LP + BCAA diet than the LP diet. However, mRNA and protein levels for peptide transporter-1 were lower in piglets fed the LP + BCAA diet as compared to the LP diet. The colonic microflora did not differ among the three groups of pigs. In conclusion, growth performance, intestinal development, and intestinal expression of AA transporters in weanling piglets are enhanced by BCAA supplementation to LP diets. Our findings provide a new molecular basis for further understanding of BCAA as functional AA in animal nutrition.
authors.affiliation: State Key Laboratory of Animal Nutrition, China Agricultural University, No. 2. Yuanmingyuan West Road, Beijing, 100193, China.
authors.forename: Shihai
authors.initials: S
authors.lastname: Zhang
authors.forename: Shiyan
authors.initials: S
authors.lastname: Qiao
authors.forename: Man
authors.initials: M
authors.lastname: Ren
authors.forename: Xiangfang
authors.initials: X
authors.lastname: Zeng
authors.forename: Xi
authors.initials: X
authors.lastname: Ma
authors.forename: Zhenlong
authors.initials: Z
authors.lastname: Wu
authors.forename: Philip
authors.initials: P
authors.lastname: Thacker
authors.forename: Guoyao
authors.initials: G
authors.lastname: Wu
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics* / Q000378:metabolism; D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004044:Dietary Proteins / Q000032:analysis / Q000378:metabolism*; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D013552:Swine / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D026905:Amino Acid Transport Systems; D000597:Amino Acids, Branched-Chain; D004044:Dietary Proteins; D026901:Membrane Transport Proteins; C043912:peptide permease