Lysine uptake by mammary gland tissue from lactating sows.

Hurley, W.L.; Wang, H.; Bryson, Jane M.; Shennan, D.B.

doi:10.2527/2000.782391x

Cited by 27 publications

(16 citation statements)

References 16 publications

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“…Amino acid extraction rates (%) across the porcine mammary glands in relation to day of lactation a 0.96% as compared with 0.67% in the study by Trottier et al (1997). Hurley et al (2000) demonstrated that in vitro lysine uptake in the sow mammary tissue occurred via a sodium-independent transport mechanism with a Km of 1.4 mM, which was approximately 10-fold higher than the arterial plasma concentration of lysine found in this study. Thus, the lack of variation in lysine A-VD by no means indicates that lysine uptake was saturated during the stage of lactation period studied herein.…”

Section: Resultscontrasting

confidence: 43%

The effect of litter size and day of lactation on amino acid uptake by the porcine mammary glands

Nielsen¹,

Trottier

Stein

et al. 2002

Journal of Animal Science

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Twelve multiparous sows (PIC Camborough 15; parity >2) were used to investigate the relationship between litter size and day of lactation, and plasma amino acid (AA) arteriovenous differences (A-VD), AA uptake, and plasma flow across the mammary glands. Sows were assigned randomly to one of the following litter sizes: 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 pigs per litter by cross fostering on d 2 postpartum. All sows were surgically fitted with catheters in the carotid artery and the main mammary vein. Matched arteriovenous blood samples were obtained on d 9, 12, 15, 18, 21, and 24 postpartum. Daily mammary uptake of AA was based on the product of plasma A-VD and daily mammary plasma flow (MPF). Daily MPF was estimated using the Fick method based on lysine conservation across the gland, and daily milk production. For the majority of AA, as litter size increased, A-VD did not increase, except for alanine (P < 0.05, linear and quadratic) and valine (P < 0.1; trend; linear and quadratic). As day of lactation increased, A-VD for the majority of AA increased (P < 0.05, linear and quadratic) except for arginine, lysine, and phenylalanine. As litter size increased, net daily mammary AA uptake increased for all indispensable AA (P = 0.001 to P < 0.05, linear and quadratic), excepting arginine. Milk production increased with increasing litter size (P < 0.001, linear) and with increasing day of lactation (P < 0.05, quadratic). Daily MPF increased (P < 0.05, linear) with increasing litter size, but did not change during the period measured from d 9 to 24. In conclusion, litter size appears to be a major determinant of net mammary AA uptake with daily mammary plasma flow a driving variable, whereas AA A-VD is a function of day of lactation and a major variable in determining net AA uptake with advancement of lactation.

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Section: Resultscontrasting

confidence: 43%

The effect of litter size and day of lactation on amino acid uptake by the porcine mammary glands

Nielsen¹,

Trottier

Stein

et al. 2002

Journal of Animal Science

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“…Cationic amino acids are actively transported into the lactating mammary gland by Na + -independent transport systems [46][47][48][49], but the cationic amino acid transporters have been poorly described in the mammary gland [28,50]. In this study, CAT-1 mRNA abundance increased during lactation when compared with the virgin rats.…”

Section: Discussionmentioning

confidence: 48%

Changes in messenger RNA abundance of amino acid transporters in rat mammary gland during pregnancy, lactation, and weaning

et al. 2009

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“…For example, low affinity transport with a K M in excess of 1 . 0 mmol/litre has similarly been described for lysine in porcine mammary tissue (Hurley et al 2000). These authors also indicated the possibility of a more complex analysis of kinetic data to that of the single saturable curve used in their work.…”

Section: Discussionmentioning

confidence: 70%

L-methionine uptake, incorporation and effects on proliferative activity and protein synthesis in bovine claw tissue explants in vitro

et al. 2007

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SUMMARYL-methionine is a sulphur-containing nutritionally essential amino acid. It has a number of important roles in epidermal and dermal tissues of the integument of animals. Failure of normal function of these tissues in the hoof (claw) is a cause of lameness in cattle. Little is known about quantitative relationships between post-absorptive concentrations of nutrients including sulphur-containing amino acids and uptake and utilization by epidermis and dermis of the bovine claw. These parameters were studied at the tissue level by use of an established in vitro claw explant system using tissue from cattle of beef or dairy origin and L-[35S]-labelled methionine as tracer. The results showed that uptake of L-methionine by freshly prepared solear explants in Dulbecco's Modified Eagle Medium/F-12 Nutrient Mix (DMEM/F12) (1:1) medium containing 1·0 mmol L-methionine/litre was concentrative after 5–8 min, essentially linear for up to 10 min and became curvilinear thereafter. Maximum uptake and steady state conditions were obtained at approximately 30 min. Further measurements were made following 21 h incubation in culture medium. Under conditions of varying concentrations of L-methionine and measurement of uptake after 30 min, the presence of a saturable curve, that obeyed Michaelis–Menten kinetics, was demonstrated. Values of 3·61 mmol/litre and 5·84 mmol/kg intracellular water/30 min were obtained for KM and Vmax, respectively. Uptake was not influenced by L-cysteine and L-cystine concentrations in the culture media.Similar culture and incubation conditions were used in subsequent studies of DNA and protein synthesis. These showed that rates of incorporation of L-methionine into protein fractions and stimulation of DNA synthesis measured by methyl-thymidine incorporation were dependent on L-methionine concentrations in the medium. Maximal rates occurred at approximately 50 μmol/litre, which is in the normal physiological range, and at 1% of maximum uptake capacity. Examination of histological sections by autoradiography showed localization of L-[35S]-labelled methionine in basal and suprabasal epidermal cells with limited retention in dermis. Measurement, by a range of histological, immunohistochemical, electrophoretic, western blotting and autoradiographic techniques, provided further evidence of L-methionine-dependent regulation of proliferation, differentiation and synthesis of proteins under physiological concentrations, by epidermal horn-forming cells.A key role for L-methionine is suggested in the production of horn in bovine claw. The extrapolation of these in vitro data provides guidance for strategies to optimize methionine supply to claw tissues in vivo. Such extrapolation suggests the appropriateness of delivery of systemic concentrations of 50 μmol L-methionine/litre to maximize proliferative and protein depositional activity in solear epidermis and dermis in vivo.

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Lysine uptake by mammary gland tissue from lactating sows.

Cited by 27 publications

References 16 publications

The effect of litter size and day of lactation on amino acid uptake by the porcine mammary glands

The effect of litter size and day of lactation on amino acid uptake by the porcine mammary glands

Changes in messenger RNA abundance of amino acid transporters in rat mammary gland during pregnancy, lactation, and weaning

L-methionine uptake, incorporation and effects on proliferative activity and protein synthesis in bovine claw tissue explants in vitro

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