Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland

X F Guan, B J Bequette, Alexander Graham Calder, P K Ku, K N Ames, N L Trottier

    Research output: Contribution to journalArticle

    24 Citations (Scopus)

    Abstract

    A kinetic model was used to examine transmembrane flux kinetics of lysine, methionine and valine across the porcine mammary gland (MG) under dietary amino acid (AA) limiting, adequate and excess conditions. Lactating sows (3 per treatment) were offered three diets: lysine-deficient [LD, 4.9 lysine and 9.9 valine (g/kg diet)], adequate (Control, 9.7 and 10.2) and valine-excess (VE, 9.8 and 13.4). On d 18 of lactation, 2-N-15-lysine, 5-methyl-H-2(3)-methlonine and 1-C-13-valine were infused into a jugular vein for 20.5 h. Milk and arterial and mammary venous blood samples were collected at 2- and 1-h intervals, respectively. Compared with Control, milk yield and litter growth rate decreased (P < 0.05) in sows fed the LD diet. Model estimates of mammary protein synthesis (PS), breakdown (PB) and net PS decreased (P < 0.05) in sows fed the LD diet. Net uptake of lysine decreased (P < 0.05) in sows fed the LID diet as a result of decreases in inward and outward transport of lysine. Inward transport of methionine tended to be reduced (P < 0.10) in sows fed the LD diet, resulting in a decrease in net methionine uptake. In sows fed the VE diet, PB was reduced (P < 0.05) and PS unchanged compared with Control. Outward transport of valine and net lysine uptake were reduced (P < 0.05), but net valine uptake was unchanged in sows fed the VE diet compared with Control. In conclusion, the kinetic model provided estimates of PS that were similar to empirical measurements of milk protein output and mammary protein accretion. Transport of lysine and methionine by the porcine MG is closely linked to regulation of mammary PS. Lysine availability has little effect on the transmembrane flux of valine.

    Original languageEnglish
    Pages (from-to)1224-1234
    Number of pages11
    JournalThe Journal of Nutrition
    Volume132
    Issue number6
    Publication statusPublished - Jun 2002

    Keywords

    • amino acid uptake
    • protein turnover
    • lactation
    • compartmental kinetic model
    • mammary gland
    • pigs
    • lactating sow
    • skeletal-muscle
    • tissue
    • transport
    • milk
    • leucine
    • valine
    • plasma
    • performance
    • specificity

    Cite this

    Guan, X. F., Bequette, B. J., Calder, A. G., Ku, P. K., Ames, K. N., & Trottier, N. L. (2002). Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland. The Journal of Nutrition, 132(6), 1224-1234.

    Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland. / Guan, X F ; Bequette, B J ; Calder, Alexander Graham; Ku, P K ; Ames, K N ; Trottier, N L .

    In: The Journal of Nutrition, Vol. 132, No. 6, 06.2002, p. 1224-1234.

    Research output: Contribution to journalArticle

    Guan, XF, Bequette, BJ, Calder, AG, Ku, PK, Ames, KN & Trottier, NL 2002, 'Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland', The Journal of Nutrition, vol. 132, no. 6, pp. 1224-1234.
    Guan XF, Bequette BJ, Calder AG, Ku PK, Ames KN, Trottier NL. Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland. The Journal of Nutrition. 2002 Jun;132(6):1224-1234.
    Guan, X F ; Bequette, B J ; Calder, Alexander Graham ; Ku, P K ; Ames, K N ; Trottier, N L . / Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland. In: The Journal of Nutrition. 2002 ; Vol. 132, No. 6. pp. 1224-1234.
    @article{07b24fbbcead4dc4a85e65b6b10f6eb2,
    title = "Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland",
    abstract = "A kinetic model was used to examine transmembrane flux kinetics of lysine, methionine and valine across the porcine mammary gland (MG) under dietary amino acid (AA) limiting, adequate and excess conditions. Lactating sows (3 per treatment) were offered three diets: lysine-deficient [LD, 4.9 lysine and 9.9 valine (g/kg diet)], adequate (Control, 9.7 and 10.2) and valine-excess (VE, 9.8 and 13.4). On d 18 of lactation, 2-N-15-lysine, 5-methyl-H-2(3)-methlonine and 1-C-13-valine were infused into a jugular vein for 20.5 h. Milk and arterial and mammary venous blood samples were collected at 2- and 1-h intervals, respectively. Compared with Control, milk yield and litter growth rate decreased (P < 0.05) in sows fed the LD diet. Model estimates of mammary protein synthesis (PS), breakdown (PB) and net PS decreased (P < 0.05) in sows fed the LD diet. Net uptake of lysine decreased (P < 0.05) in sows fed the LID diet as a result of decreases in inward and outward transport of lysine. Inward transport of methionine tended to be reduced (P < 0.10) in sows fed the LD diet, resulting in a decrease in net methionine uptake. In sows fed the VE diet, PB was reduced (P < 0.05) and PS unchanged compared with Control. Outward transport of valine and net lysine uptake were reduced (P < 0.05), but net valine uptake was unchanged in sows fed the VE diet compared with Control. In conclusion, the kinetic model provided estimates of PS that were similar to empirical measurements of milk protein output and mammary protein accretion. Transport of lysine and methionine by the porcine MG is closely linked to regulation of mammary PS. Lysine availability has little effect on the transmembrane flux of valine.",
    keywords = "amino acid uptake, protein turnover, lactation, compartmental kinetic model, mammary gland, pigs, lactating sow, skeletal-muscle, tissue, transport, milk, leucine, valine, plasma, performance, specificity",
    author = "Guan, {X F} and Bequette, {B J} and Calder, {Alexander Graham} and Ku, {P K} and Ames, {K N} and Trottier, {N L}",
    year = "2002",
    month = "6",
    language = "English",
    volume = "132",
    pages = "1224--1234",
    journal = "The Journal of Nutrition",
    issn = "0022-3166",
    publisher = "American Society for Nutrition",
    number = "6",

    }

    TY - JOUR

    T1 - Amino acid availability affects amino acid flux and protein metabolism in the porcine mammary gland

    AU - Guan, X F

    AU - Bequette, B J

    AU - Calder, Alexander Graham

    AU - Ku, P K

    AU - Ames, K N

    AU - Trottier, N L

    PY - 2002/6

    Y1 - 2002/6

    N2 - A kinetic model was used to examine transmembrane flux kinetics of lysine, methionine and valine across the porcine mammary gland (MG) under dietary amino acid (AA) limiting, adequate and excess conditions. Lactating sows (3 per treatment) were offered three diets: lysine-deficient [LD, 4.9 lysine and 9.9 valine (g/kg diet)], adequate (Control, 9.7 and 10.2) and valine-excess (VE, 9.8 and 13.4). On d 18 of lactation, 2-N-15-lysine, 5-methyl-H-2(3)-methlonine and 1-C-13-valine were infused into a jugular vein for 20.5 h. Milk and arterial and mammary venous blood samples were collected at 2- and 1-h intervals, respectively. Compared with Control, milk yield and litter growth rate decreased (P < 0.05) in sows fed the LD diet. Model estimates of mammary protein synthesis (PS), breakdown (PB) and net PS decreased (P < 0.05) in sows fed the LD diet. Net uptake of lysine decreased (P < 0.05) in sows fed the LID diet as a result of decreases in inward and outward transport of lysine. Inward transport of methionine tended to be reduced (P < 0.10) in sows fed the LD diet, resulting in a decrease in net methionine uptake. In sows fed the VE diet, PB was reduced (P < 0.05) and PS unchanged compared with Control. Outward transport of valine and net lysine uptake were reduced (P < 0.05), but net valine uptake was unchanged in sows fed the VE diet compared with Control. In conclusion, the kinetic model provided estimates of PS that were similar to empirical measurements of milk protein output and mammary protein accretion. Transport of lysine and methionine by the porcine MG is closely linked to regulation of mammary PS. Lysine availability has little effect on the transmembrane flux of valine.

    AB - A kinetic model was used to examine transmembrane flux kinetics of lysine, methionine and valine across the porcine mammary gland (MG) under dietary amino acid (AA) limiting, adequate and excess conditions. Lactating sows (3 per treatment) were offered three diets: lysine-deficient [LD, 4.9 lysine and 9.9 valine (g/kg diet)], adequate (Control, 9.7 and 10.2) and valine-excess (VE, 9.8 and 13.4). On d 18 of lactation, 2-N-15-lysine, 5-methyl-H-2(3)-methlonine and 1-C-13-valine were infused into a jugular vein for 20.5 h. Milk and arterial and mammary venous blood samples were collected at 2- and 1-h intervals, respectively. Compared with Control, milk yield and litter growth rate decreased (P < 0.05) in sows fed the LD diet. Model estimates of mammary protein synthesis (PS), breakdown (PB) and net PS decreased (P < 0.05) in sows fed the LD diet. Net uptake of lysine decreased (P < 0.05) in sows fed the LID diet as a result of decreases in inward and outward transport of lysine. Inward transport of methionine tended to be reduced (P < 0.10) in sows fed the LD diet, resulting in a decrease in net methionine uptake. In sows fed the VE diet, PB was reduced (P < 0.05) and PS unchanged compared with Control. Outward transport of valine and net lysine uptake were reduced (P < 0.05), but net valine uptake was unchanged in sows fed the VE diet compared with Control. In conclusion, the kinetic model provided estimates of PS that were similar to empirical measurements of milk protein output and mammary protein accretion. Transport of lysine and methionine by the porcine MG is closely linked to regulation of mammary PS. Lysine availability has little effect on the transmembrane flux of valine.

    KW - amino acid uptake

    KW - protein turnover

    KW - lactation

    KW - compartmental kinetic model

    KW - mammary gland

    KW - pigs

    KW - lactating sow

    KW - skeletal-muscle

    KW - tissue

    KW - transport

    KW - milk

    KW - leucine

    KW - valine

    KW - plasma

    KW - performance

    KW - specificity

    M3 - Article

    VL - 132

    SP - 1224

    EP - 1234

    JO - The Journal of Nutrition

    JF - The Journal of Nutrition

    SN - 0022-3166

    IS - 6

    ER -