Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-10T15:31:06.620Z Has data issue: false hasContentIssue false
  • English
  • Français

Splanchnic-bed transfers of amino acids in sheep blood and plasma, as monitored through use of a multiple U-13C-labelled amino acid mixture

Published online by Cambridge University Press:  09 March 2007

G. E. Lobley ,
A. Connell ,
D. K. Revell ,
B. J. Bequette ,
D. S. Brown  and
A. G. Calder
G. E. Lobley
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
A. Connell
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
D. K. Revell
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
B. J. Bequette
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
D. S. Brown
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
A. G. Calder
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The response in whole-body and splanchnic tissue mass and isotope amino acid transfers in both plasma and blood has been studied in sheep offered 800 g lucerne (Medicago sutiva) pellets/d. Amino acid mass transfers were quantified over a 4 h period,by arterio-venous procedures, across the portal-drained viscera (PDV) and liver on day 5 of an intravenous infusion of either vehicle or the methylated products, choline (0.5 g/d) plus creatine (10 g/d). Isotopic movements were monitored over the same period during a 10 h infusion of a mixture of U-13C-labelled amino acids obtained from hydrolysis of labelled algal cells. Sixteen amino acids were monitored by gas chromatography-mass spectrometry, with thirteen of these analysed within a single chromatographic analysis. Except for methionine, which is discussed in a previous paper, no significant effects of choline plus creatine infusion were observed on any of the variables reported. Whole-body protein irreversible-loss rates ranged from 158 to 245 g/d for the essential amino acids, based on the relative enrichments (dilution of the U-13C molecules by those unlabelled) of free amino acids in arterial plasma, and 206-519 g/d, when blood free amino acid relative enrichments were used for the calculations. Closer agreement was obtained between lysine, threonine, phenylalanine and the branched-chain amino acids. Plasma relative enrichments always exceeded those in blood (P < 0.001), possibly due to hydrolysis of peptides or degradation of protein within the erythrocyte or slow equilibration between plasma and the erythrocyte. Net absorbed amino acids across the PDV were carried predominantly in the plasma. Little evidence was obtained of any major and general involvement of the erythrocytes in the transport of free amino acids from the liver. Net isotope movements also supported these findings. Estimates of protein synthesis rates across the PDV tissues from [U-13C] leucine kinetics showed good agreement with previous values obtained with single-labelled leucine. Variable rates were obtained between the essential amino acids, probably due to different intracellular dilutions. Isotope dilution across the liver was small and could be attributed predominantly to uni-directional transfer from extracellular sources into the hepatocytes and this probably dominates the turnover of the intracellular hepatic amino acid pools.

Keywords

Stable isotopesAmino acidsProtein metabolismLiver
Type
Research Article
Information
British Journal of Nutrition , Volume 75 , Issue 2 , February 1996 , pp. 217 - 235
Copyright
Copyright © The Nutrition Society 1996

References

REFERENCES

Adams, E., McFadden, M. & Smith, E. L. (1952). Peptidases of erythrocytes. 1. Distribution in man and other species. Journal of Biological Chemistry 198, 663–670.CrossRefGoogle Scholar
Aoki, T. T., Brennan, M. F., Muller, W. A., Soeldner, J. S., Alpert, J. S., Saltz, S. B., Kaufman, R. L., Tan, M. H. & Cahill, G. F. (1976). Amino acid levels across normal forearm muscle and splanchnic bed after a protein meal. American Journal of Clinical Nutrition 29, 340–350.CrossRefGoogle ScholarPubMed
Backwell, F. R. C., Bequette, B. J., Wilson, D., Calder, A. G., Wray-Cahan, D., Metcalf, J. A., MacRae, J. C., Beever, D. E. & Lobley, G. E. (1994). The utilisation of dipeptides by the caprine mammary gland for milk protein synthesis. American Journal of Physiology 267, Rl–R6.Google ScholarPubMed
Barrett, E. J., Revkin, J. H., Young, L. H., Zaret, B. L., Jacob, R. & Gelfand, R. A. (1987). An isotopic method for measurement of muscle protein synthesis and degradation in vivo. Biochemical Journal 245, 223–228.CrossRefGoogle ScholarPubMed
Bennet, W. M., Connacher, A. A., Scrimgeour, C. M. & Rennie, M. J. (1990). The effect of amino acid infusion on leg protein turnover assessed by L-[15N]phenylalanine and L-[1-13C]leucine exchange. European Journal of Clinical Investigation 20, 41–50.CrossRefGoogle ScholarPubMed
Berthold, H. K., Hachey, D. L., Reeds, P. J., Thomas, O. P., Hoeksema, S. & Klein, P. D. (1991). Uniformly 13C-labelled algal protein used to determine amino acid essentiality in vivo. Proceedings of the National Academy of Sciences, USA 88, 8091–8095.Google Scholar
Biolo, G. Tessari, P., Inchiostro, S., Bruttomesso, D., Fongher, C., Sabadin, L., Fratton, M. G., Valerio, A. & Tiengo, A. (1992). Leucine and phenylalanine kinetics during mixed meal ingestion: a multiple tracer approach. American Journal of Physiology 262, E455–E463.Google ScholarPubMed
Calder, A. G. & Smith, A. (1988). Stable isotope ratio analysis of leucine and ketoisocaproic acid in blood plasma by gas chromatography\mass spectrometry. Rapid Communications in Mass Spectrometry 2, 14–16.CrossRefGoogle ScholarPubMed
Campbell, I. M. (1974). Incorporation and dilution values - their calculation in mass spectrally assayed stable isotope labelling experiments. Bioorganic Chemistry 3, 386–397.CrossRefGoogle Scholar
Covolo, G. C. & West, R. (1947). The activity of arginase in red blood cells. Journal of Clinical Endocrinology 7, 325–330.CrossRefGoogle ScholarPubMed
Cronjé, P. B., Nolan, J. V. & Leng, R. A. (1992). Amino acid metabolism and wholebody protein turnover in lambs fed roughage-based diets: 2. Methionine metabolism and a comparison of estimates of whole-body protein turnover derived from lysine, leucine and methionine kinetics. South African Journal of Animal Science 22, 201–206.Google Scholar
Dauman, D., Froguel, P., Rongier, M. & Robert, J.J. (1989). Amino acid exchange between plasma and Erythrocytes in vivo in humans. Journal of Applied Physiology 67, 2383–2388.Google Scholar
Dewes, L. R., Conway, W. P. & Gilboe, D. D. (1977). Net amino acid transport between plasma and erythrocytes and perfused dog brain. American Journal of Physiology 233, E320–E235.Google Scholar
Eisemann, J. H., Hammond, A. C. & Rumsey, T. D. (1989). Tissue protein synthesis and nucleic acid concentrations in steers streated with somatotropin. British Journal of Nutrition 62, 657–671.CrossRefGoogle Scholar
Elwyn, D. H., Launder, W. J., Parikh, H. C. & Wise, E. M. Jr (1972). Roles of plasma and erythrocytes in interorgan transport of amino acids in dogs. American Journal of Physiology 222, 1333–1342.CrossRefGoogle ScholarPubMed
Garlick, P. J., Millward, D. J. & James, W. P. T. (1973). The diurnal response of muscle and liver protein synthesis in vivo in meal-fed rats. Biochemical Journal 136, 935–945.CrossRefGoogle ScholarPubMed
Harris, P. M., Lee, J., Sinclair, B. R., Treloar, B. F. & Gurnsey, M. P. (1994). Effect of food intake on energy and protein metabolism in the skin of Romney sheep. British Journal of Nutrition 71, 647–660.CrossRefGoogle ScholarPubMed
Harris, P. M., Lobley, G. E., Skene, P. A., Buchan, V., Calder, A. G., Anderson, S. E. & Connell, A. (1992). Effect of food intake on hind-limb and whole-body protein metabolism in young growing sheep: chronic studies based on arterio-venous techniques. British Journal of Nutrition 68, 388–407.CrossRefGoogle ScholarPubMed
Heitmann, R. N. & Bergman, E. N. (1980). Transport of amino acids in whole blood and plasma of sheep. American Journal of Physiology 239, E242–.Google ScholarPubMed
Houlier, M. L., Patureau-Mirand, P., Durand, D., Bauchart, D., Lefaivre, J. & Bayle, A. (1991). Transport des acides aminks dans l'aire splanchnic par le plasma sanguin et le sang chez le veau prkruminant (Transport of amino acids in blood and plasma across the splanchnic region of preruminant calves). Reproduction, Nutrition and Development 31, 399–410.CrossRefGoogle Scholar
Lobley, G. E., Connell, A., Lomax, M. A., Brown, D. S., Milne, E., Calder, A. G. & Farningham, D. A. H. (1995). Hepatic detoxification of ammonia in the ovine liver, possible consequences for amino acid catabolism. British Journal of Nutrition 13, 667–685.CrossRefGoogle Scholar
Lobley, G. E., Connell, A., Milne, E., Newman, A. M. & Ewing, T. A. (1994). Proteinsynthesis in splanchnic tissues of sheep offered two levels of intake. British Journal of Nutrition 71, 3–12.CrossRefGoogle Scholar
Lobley, G. E., Connell, A. & Revell, D. K. (1996). The importance of transmethylation reactions to methionine metabolism in sheep; effects of supplementation withthe methyl group acceptors, creatine and choline. British Journal of Nutrition 75, 47–56.CrossRefGoogle Scholar
Lobley, G. E., Milne, V., Lovie, J. M., Reeds, P. J. & Pennie, K. (1980). Whole body and tissue protein synthesis in cattle. British Journal of Nutrition 43, 491–502.CrossRefGoogle ScholarPubMed
Lochs, H., Morse, E. L. & Adibi, S. A. (1990). Uptake and metabolism of dipeptides by human red blood cells. Biochemical Journal 211, 133–137.CrossRefGoogle Scholar
MacKenzie, S. L. & Tenaschuk, D. (1979 a). Quantitative formation of N(O,S)-hepatafluorobutyryl isobutyl amino acids for gas chromatographic analysis. 1. Esterification. Journal of Chromatography 171, 195–208.CrossRefGoogle Scholar
MacKenzie, S. L. & Tenaschuk, D. (1979 b). Quantitative formation of N(O,S)-heptafluorobutyryl isobutyl amino acids for gas chromatographic analysis. II. Acylation. Journal of Chromatography 173, 53–63.CrossRefGoogle Scholar
MacRae, J. C. & Reeds, P. J. (1980). Prediction of protein deposition in ruminants. In Protein Deposition in Animals, pp. 225–249 [Buttery, P. J. and Lindsay, D. B. editors]. London: Butterworths.CrossRefGoogle Scholar
MacRae, J. C., Walker, A., Brown, D. & Lobley, G. E. (1993). Accretion of totalprotein and individual amino acids by organs and tissues of growing lambs and the ability of nitrogen balance techniques to quantitate protein retention. Animal Production 51, 237–245.Google Scholar
Motil, K. J., Opekun, A. R., Montandon, C. R., Berthold, H. K., Davis, T. A., Klein, P. D. & Reeds, P. J. (1994). Leucine oxidation changes rapidly after dietary protein intake is altered in adult women but lysine flux is unaltered as is lysine incorporation into VLDL-apolipoprotein B-100. Journal of Nutrition 124, 41–51.CrossRefGoogle ScholarPubMed
Müller, M., Dubiel, W., Rathmann, J. & Rapoport, S. (1980). Determination and characteristics of energy dependent proteolysis in rabbit reticulocytes. European Journal of Biochemistry 109, 405–410.CrossRefGoogle ScholarPubMed
Obled, C., Barre, F., Millward, D. J. & Arnal, M. (1989). Whole body protein synthesis: studies with different amino acids in the rat. American Journal of Physiology 257, E63–E646.Google ScholarPubMed
Odoom, J. E., Campbell, I. D., Ellory, J. C. & King, G. F. (1990). Characterizationof peptide fluxes into human erythrocytes. Biochemical Journal 267, 141–147.CrossRefGoogle Scholar
Pell, J. M., Calderone, E. M. & Bergman, E. N. (1986). Leucine and a-ketoisocaproate metabolism and interconversions in fed and fasted sheep. Metabolism 35, 1005–1016.CrossRefGoogle ScholarPubMed
Rapoport, S., Dubiel, W. & Muller, M. (1985). Proteolysis of mitochondria in reticulocytes during maturation is accompanied by a high rate of ATP hydrolysis. FEBS Letters 180, 249–259.CrossRefGoogle ScholarPubMed
Reynolds, C. K. & Huntington, G. B. (1988). Partition of portal-drained visceral net flux in beef steers. 1. Blood flow and net flux of oxygen, glucose and nitrogenous compounds across stomach and post-stomach tissues. British Journal of Nutrition 60, 539–552.CrossRefGoogle ScholarPubMed
Tessari, P., Biolo, G., Inchiostro, S., Sacca, L., Nosadini, R., Boscarato, M. T., Trevisan, R., de Kreutzenberg, S. V. & Tiengo, A. (1990). Effects of insulin on whole body and forearm leucine and KIC metabolism in type 1 diabetes. American Journalof Physiology 259, E96–E103.Google ScholarPubMed
Vadgama, J. V. & Christensen, H. N. (1985). Discrimination of Na+-independent transport systems L, T and ASC in erythrocytes. Journal of Biological Chemistry 260, 2912–2921.CrossRefGoogle Scholar
Wolff, J. E., Bergmann, E. N. & Williams, H. H. (1972). Net metabolism of plasma amino acids by liver and portal-drained viscera of fed sheep. American Journal of Physiology 223, 438–446.CrossRefGoogle ScholarPubMed
Young, J. D. & Ellory, J. C. (1977). Red cell amino acid transport. In Membrane Transport in Red Cells, pp. 301–325 [Ellory, J. C. and Lew, V. L., editors]. London: Academic Press.Google Scholar
Young, J. D., Ellory, J. C. & Tucker, E. M. (1976). Amino acid transport in normal and glutathione-deficient sheep erythrocytes. Biochemical Journal 154, 43–48.CrossRefGoogle ScholarPubMed