Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-23T21:26:41.978Z Has data issue: false hasContentIssue false
  • English
  • Français

Protein synthesis and degradation in the mammary gland of lactating goats

Published online by Cambridge University Press:  01 June 2009

V. Hutton Oddy ,
Derek B. Lindsay  and
Ivan R. Fleet
V. Hutton Oddy
Affiliation:
AFRO Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT, UK
Derek B. Lindsay
Affiliation:
AFRO Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT, UK
Ivan R. Fleet
Affiliation:
AFRO Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT, UK
Get access Rights & Permissions [Opens in a new window]

Summary

Lactating goats were given a close arterial infusion of [1-14C]leucine and [4,5-3H]4-methyl-2-oxopentanoic acid into one half of the mammary gland at 2–3 weeks and 34–39 weeks after kidding. Rates of protein synthesis, degradation and net output were determined from measurements of arteriovenous difference and blood flow using a model of leucine metabolism previously developed for muscle (Oddy & Lindsay, 1986). Protein leucine output in milk (Y μmol/min) correlated well with the difference between synthesis and degradation (X μmol/min) derived from the model:

There was substantial synthesis and degradation of protein within the mammary gland. Although only an approximate value could be obtained for the partitioning of protein synthesis and degradation between tissue and milk proteins, there was evidence of appreciable turnover of both. There was no significant difference between mammary leucine and protein metabolism in early and late lactation other than that imparted by a greater mass of mammary tissue in early lactation, although there was a tendency for greater oxidation of leucine in late lactation.

Type
Original articles
Information
Journal of Dairy Research , Volume 55 , Issue 2 , May 1988 , pp. 143 - 154
Copyright
Copyright © Proprietors of Journal of Dairy Research 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Annison, E. F. & Linzell, J. L. 1964 The oxidation and utilization of glucose and acetate by the mammary gland of the goat in relation to their over-all metabolism and to milk formation. Journal of Physiology 175 372–385CrossRefGoogle ScholarPubMed
Baumrucker, C. R. 1985 Amino acid transport systems in bovine mammary tissue. Journal of Dairy Science 68 2436–2451Google Scholar
Bleehen, N. M. & Fisher, R. B. 1954 The action of insulin in the isolated rat heart. Journal of Physiology 123 260–276CrossRefGoogle ScholarPubMed
Clark, J. H., Spires, H. R. & Davis, C. L. 1978 Uptake and metabolism of nitrogenous components by the lactating mammary gland. Federation Proceedings 37 1233–1238Google Scholar
Davis, S. R. & Bickerstaffe, R. 1978 Mammary glucose uptake in the lactating ewe and the use of methionine arterio-venous difference for the calculation of mammary blood flow. Australian Journal of Biological Sciences 31 133–139CrossRefGoogle ScholarPubMed
Fleet, I. R. & Linzell, J. L. 1964 A rapid method of estimating fat in very small quantities of milk. Journal of Physiology 175 15–17PGoogle Scholar
Fleet, I. R. & Mepham, T. B. 1983 Physiological methods used in the study of mammary substrate utilization in ruminants. In Biochemistry of Lactation, pp. 469–491 (Ed. Mepham, T. B.). Amsterdam: ElsevierGoogle Scholar
Goldwater, W. H. & Stetten, D. 1947 Studies in fetal metabolism. Journal of Biological Chemistry 169 723–738CrossRefGoogle ScholarPubMed
Hortsch, M., Avossa, D. & Meyer, D. I. 1985 A structural and functional analysis of the docking protein. Journal of Biological Chemistry 260 9137–9145Google Scholar
Linzell, J. L. 1960 Transplantation of mammary glands. Nature 188 596–598CrossRefGoogle ScholarPubMed
Linzell, J. L. 1966 a Measurement of venous flow by continuous thermodilution and its application to measurement of mammary blood flow in the goat. Circulation Research 18 745–754CrossRefGoogle ScholarPubMed
Linzell, J. L. 1966 b Measurement of udder volume in live goats as an index of mammary growth and function. Journal of Dairy Science 49 307–311CrossRefGoogle Scholar
Linzell, J. L. 1974 Mammary blood flow and methods of identifying and measuring precursors of milk. In Lactation, vol. 1, pp. 143–225 (Eds Larson, B. L. and Smith, V. R.). New York: Academic PressGoogle Scholar
Lobley, G. E., Reeds, P. J. & Pennie, K. 1978 Protein synthesis in cattle. Proceedings of the Nutrition Society 37 96AGoogle Scholar
Mepham, T. B. 1982 Amino acid utilization by lactating mammary gland. Journal of Dairy Science 65 287–298Google Scholar
Mercier, J.-C. & Gaye, P. 1982 Early events in secretion of main milk proteins: occurrence of precursors. Journal of Dairy Science 65 299–316CrossRefGoogle ScholarPubMed
Meyer, D. I. 1982 The signal hypothesis – a working model. Trends in Biochemical Science 7 320–321Google Scholar
Meyer, D. I., Krause, E. & Dobberstein, B. 1982 Secretory protein translocation across membranes – the role of the ‘docking protein’. Nature 297, 647–650CrossRefGoogle ScholarPubMed
Nissen, S. & Raymond, M. W. 1983 Importance of α-ketoisocaproate in the movement of leucine carbon between liver and peripheral tissues. 4th International Symposium of Protein Metabolism and Nutrition, vol. 2, pp. 85–87 (Les Colloques de l'INRA 16)Google Scholar
Oddy, V. H. & Lindsay, D. B. 1986 Determination of rates of protein synthesis, gain and degradation in intact hind-limb muscle of lambs. Biochemical Journal 233 417–425Google Scholar
O'Hare, M., Kirwin, P., Razooki-Hasan, H., Wilde, C., White, D. A. & Mayer, R. J. 1986 Secretion-coupled protein degradation: studies on mammary casein. Biochimica et Biophysica Acta 889 49–58CrossRefGoogle ScholarPubMed
Peaker, M. & Fleet, T. R. 1979 Autotransplantation of the goat mammary gland. Journal of Dairy Research 46 589–598Google Scholar
Roets, E., Massart-Leën, A.-M., Peeters, G. & Verbeke, R. 1983 Metabolism of leucine by the isolated perfused goat udder. Journal of Dairy Research 50 413–424CrossRefGoogle ScholarPubMed
Seldinger, S. I. 1953 Catheter replacement of the needle in percutaneous arteriography: a new technique. Acta Radiologica 39 368–376Google Scholar
Verbeke, R., Lauryssens, M., Peeters, G. & James, A. T. 1959 Incorporation of DL(1-14C)leucine and (1-14C)isOvaleric acid into milk constituents by the perfused cow's udder. Biochemical Journal 73 24–29Google Scholar
Wilde, C. J., Paskin, X., Saxton, J. & Mayer, R. J. 1980 Protein degradation during terminal cytodirferentiation: studies on mammary gland in organ culture. Biochemical Journal 192 311–320CrossRefGoogle ScholarPubMed
Wohlt, J. E., Clark, J. H., Derrig, R. G. & Davis, C. L. 1977 Valine, leucine, and isoleucine metabolism by lactating bovine mammary tissue. Journal of Dairy Science 60 1875–1882CrossRefGoogle ScholarPubMed