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Metabolism of [U-14C; 2, 3-3H]-L-valine by the isolated perfused goat udder

Published online by Cambridge University Press:  01 June 2009

Eddy Roets
Affiliation:
Department of Physiology, Faculty of the University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium
Anne-Marie Massart-LeëN
Affiliation:
Department of Physiology, Faculty of the University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium
Roger Verbeke
Affiliation:
Department of Physiology, Faculty of the University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium
Georges Peeters
Affiliation:
Department of Physiology, Faculty of the University of Ghent, Casinoplein 24, B-9000 Ghent, Belgium

Summary

Two lactating mammary glands excised from 2 goats were perfused for several hours in the presence of [U-14C; 2,3-3H]-L-valine and received adequate quantities of glucose, acetate and amino acids. In the synthesized milk 96 and 89% respectively of the casein valine was derived from free plasma valine. Valine was extensively catabolized by mammary tissue, resulting in a considerable 14CO2 production and in the incorporation of 14C into milk citric acid and to a lesser extent into casein aspartic acid and glutamic acid. About 30% of the valine molecules which were taken up by the mammary gland were oxidized to CO2 and 70% were incorporated in casein as valine residues. About 10% of the plasma valine molecules were reversibly transaminated during one passage through the udder. An important amount of radioactivity of plasma was present in unknown metabolites. Only 7% of this activity was localized in isobutyrate. The radioactivity of total milk fat was very low. Mainly iso-14:0, iso-16:0 and 15:0 were labelled.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1979

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References

REFERENCE

Bickerstaffe, R., Annison, E. F. & Linzell, J. L. (1974). Journal of Agricultural Science 82, 71.CrossRefGoogle Scholar
Christopherson, S. W. & Glass, R. L. (1969). Journal of Dairy Science 52, 1289.CrossRefGoogle Scholar
Coward, R. F. & Smith, P. (1968). Journal of Chromatography 33, 508.CrossRefGoogle Scholar
Cowie, A. T., Duncombe, W. G., Folley, S. J., French, T. H., Glascock, R. F., Massart, L., Peeters, G. J. & Popjak, G. (1951). Biochemical Journal 49, 610.CrossRefGoogle Scholar
Davis, S. R. & Mepham, T. B. (1976). Biochemical Journal 156, 553.CrossRefGoogle Scholar
Derrig, R. G., Davis, C. L. & Clark, J. H. (1973). Journal of Dairy Science 56, 651.Google Scholar
Egan, A. R., Moller, F. & Black, A. L. (1970). Journal of Nutrition 100, 419.CrossRefGoogle Scholar
Gardner, J. W. & Thompson, G. E. (1974). Analyst 99, 326.CrossRefGoogle Scholar
Hardwick, D. C., Linzell, J. L. & Price, S. M. (1961). Biochemical Journal 80, 37.CrossRefGoogle Scholar
Hendler, R. W. (1964). Analytical Biochemistry 7, 110.CrossRefGoogle Scholar
James, A. T., Peeters, G. & Lauryssens, M. (1956). Biochemical Journal 64, 726.CrossRefGoogle Scholar
Keeney, M. (1956). Journal of the Association of Official Agricultural Chemists 39, 212.Google Scholar
Keeney, M., Katz, I. & Allison, M. J. (1962). Journal of the American Oil Chemists′ Society 39, 198.CrossRefGoogle Scholar
Landaas, S. (1975). Clinica Chimica Acta 64, 143.CrossRefGoogle Scholar
Linzell, J. L. (1960). Journal of Physiology 153, 492.CrossRefGoogle Scholar
Linzell, J. L., Mepham, T. B., Annison, E. F. & West, C. E. (1969). British Journal of Nutrition 23, 319.CrossRefGoogle Scholar
Massart-Leën, A. -M., Florescu, S., Verbeke, R. & Peeters, G. (1970). Journal of Dairy Research 37, 373.CrossRefGoogle Scholar
Mepham, T. B. & Linzell, J. L. (1966). Biochemical Journal 101, 76.CrossRefGoogle Scholar
Perry, T. L., Stedman, D. & Hansen, S. (1968). Journal of Chromatography 38, 460.CrossRefGoogle Scholar
Roets, E., Verbeke, R., Massart-Leën, A. -M. & Peeters, G. (1974). Biochemical Journal 144, 435.CrossRefGoogle Scholar
Roets, E., Verbeke, R., Peeters, G., Axmann, H. & Proksch, G. (1976). In Nuclear Techniques in Animal Production and Health, p. 327. Vienna: International Atomio Energy Agency.Google Scholar
Rognstad, R., Wals, P. & Katz, J. (1975). Journal of Biological Chemistry 250, 8642.CrossRefGoogle Scholar
Verbeke, R., Lauryssens, M., Peeters, G. & James, A. T. (1959). Biochemical Journal 73, 24.CrossRefGoogle Scholar
Verbeke, R. & Peeters, G. (1965). Biochemical Journal 94, 183.CrossRefGoogle Scholar
Verbeke, R., Peeters, G., Massart-Leën, A. -M. & Cocquyt, G. (1968). Biochemical Journal 106, 719.CrossRefGoogle Scholar