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. 1972 Feb;126(3):477–490. doi: 10.1042/bj1260477

Studies on the mode of uptake of blood triglycerides by the mammary gland of the lactating goat. The uptake and incorporation into milk fat and mammary lymph of labelled glycerol, fatty acids and triglycerides

C E West 1,*, R Bickerstaffe 1, E F Annison 1, J L Linzell 1
PMCID: PMC1178403  PMID: 4672665

Abstract

1. The mode of uptake of the precursors of milk fat by the mammary gland of the lactating goat has been examined by infusing radioactive fatty acids, glucerol or doubly labelled triglycerides into the mammary artery or jugular vein of animals surgically prepared to permit samples of arterial and venous blood to be withdrawn without disturbance to the animal. 2. Acetate was taken up by the mammary gland and incorporated into milk fat. The decrease in the specific radioactivity of blood acetate across the gland was evidence of acetate production, but there was no significant release of labelled lipid from the mammary gland. 3. When labelled long-chain fatty acids or glycerol were infused into the lactating goat, there was extensive transfer of radioactivity into milk in spite of the absence of net uptake of substrate by the mammary gland. The decrease in the specific radioactivity of each substrate across the mammary gland, however, showed that both fatty acids and glycerol were simultaneously taken up and released by mammary tissue. 4. The infusion of chylomicra and triglyceride emulsions labelled with 3H and 14C revealed that both glycerol and fatty acids were released during triglyceride uptake by mammary tissue. Changes in the 3H/14C ratio during the transfer of triglyceride from blood into milk showed that at least 80% of the triglyceride was hydrolysed during uptake, but the potential re-utilization of both products of hydrolysis for triglyceride synthesis in mammary tissue implied that only a minimum value could be obtained from the change in the ratio. 5. The time-course of the transfer of 3H and 14C into milk and lymph were closely similar after the infusion of [2-3H]glycerol tri[1-14C]oleate or of a mixture of [2-3H]glycerol and [1-14C]oleate. 6. The results were consistent with the hypothesis that plasma triglycerides are extensively or completely hydrolysed during mammary uptake.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. AL-KASSAB S., BOYLAND E., WILLIAMS K. An enzyme from rat liver catalysing conjugations with glutathione. 2. Replacement of nitro groups. Biochem J. 1963 Apr;87:4–9. doi: 10.1042/bj0870004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. ANNISON E. F., LINZELL J. L. THE OXIDATION AND UTILIZATION OF GLUCOSE AND ACETATE BY THE MAMMARY GLAND OF THE GOAT IN RELATION TO THEIR OVER-ALL METABOLISM AND MILK FORMATION. J Physiol. 1964 Dec;175:372–385. doi: 10.1113/jphysiol.1964.sp007522. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Anfinsen C. B., Boyle E., Brown R. K. The Role of Heparin in Lipoprotein Metabolism. Science. 1952 May 30;115(2996):583–586. doi: 10.1126/science.115.2996.583. [DOI] [PubMed] [Google Scholar]
  4. Annison E. F., Linzell J. L., Fazakerley S., Nichols B. W. The oxidation and utilization of palmitate, stearate, oleate and acetate by the mammary gland of the fed goat in relation to their overall metabolism, and the role of plasma phospholipids and neutral lipids in milk-fat synthesis. Biochem J. 1967 Mar;102(3):637–647. doi: 10.1042/bj1020637. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Annison E. F., Linzell J. L., West C. E. Mammary and whole animal metabolism of glucose and fatty acids in fasting lactating goats. J Physiol. 1968 Jul;197(2):445–459. doi: 10.1113/jphysiol.1968.sp008569. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. BARRY J. M., BARTLEY W., LINZELL J. L., ROBINSON D. S. THE UPTAKE FROM THE BLOOD OF TRIGLYCERIDE FATTY ACIDS OF CHYLOMICRA AND LOW-DENSITY LIPOPROTEINS BY THE MAMMARY GLAND OF THE GOAT. Biochem J. 1963 Oct;89:6–11. doi: 10.1042/bj0890006. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. CORNWELL D. G., KRUGER F. A., HAMWI G. J., BROWN J. B. Studies on the characterization of human serum lipoproteins separated by ultracentrifugation in a density gradient. I. Serum lipoproteins in normal, hyperthyroid and hypercholesterolemic subjects. Am J Clin Nutr. 1961 Jan-Feb;9:24–40. doi: 10.1093/ajcn/9.1.24. [DOI] [PubMed] [Google Scholar]
  8. FOLCH J., LEES M., SLOANE STANLEY G. H. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem. 1957 May;226(1):497–509. [PubMed] [Google Scholar]
  9. GARTON G. A., DUNCAN W. R. THE POSITIONAL DISTRIBUTION OF FATTY ACIDS IN THE TRIGLYCERIDES OF INTESTINAL LYMPH, LIVER AND ADIPOSE TISSUE OF THE SHEEP. Biochim Biophys Acta. 1965 Apr 5;98:436–438. [PubMed] [Google Scholar]
  10. HOLLENBERG C. H. Effect of nutrition on activity and release of lipase from rat adipose tissue. Am J Physiol. 1959 Sep;197:667–670. doi: 10.1152/ajplegacy.1959.197.3.667. [DOI] [PubMed] [Google Scholar]
  11. HOLLENBERG C. H. The effect of fasting on the lipoprotein lipase activity of rat heart and diaphragm. J Clin Invest. 1960 Aug;39:1282–1287. doi: 10.1172/JCI104144. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. LASCELLES A. K., MORRIS B. Surgical techniques for the collection of lymph from unanaesthetized sheep. Q J Exp Physiol Cogn Med Sci. 1961 Jul;46:199–205. doi: 10.1113/expphysiol.1961.sp001536. [DOI] [PubMed] [Google Scholar]
  13. LASCELLES A. K., MORRIS B. The flow and composition of lymph from the mammary gland in merino sheep. Q J Exp Physiol Cogn Med Sci. 1961 Jul;46:206–215. doi: 10.1113/expphysiol.1961.sp001537. [DOI] [PubMed] [Google Scholar]
  14. LINZELL J. L. The flow and composition of mammary gland lymph. J Physiol. 1960 Oct;153:510–521. doi: 10.1113/jphysiol.1960.sp006551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Linzell J. L. The magnitude and mechanisms of the uptake of milk precursors by the mammary gland. Proc Nutr Soc. 1968 Mar;27(1):44–52. doi: 10.1079/pns19680011. [DOI] [PubMed] [Google Scholar]
  16. MCBRIDE O. W., KORN E. D. THE LIPOPROTEIN LIPASE OF MAMMARY GLAND AND THE CORRELATION OF ITS ACTIVITY TO LACTATION. J Lipid Res. 1963 Jan;4:17–20. [PubMed] [Google Scholar]
  17. Mayes P. A., Felts J. M. The functional status of lipoprotein lipase in rat liver. Biochem J. 1968 Jul;108(3):483–487. doi: 10.1042/bj1080483. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. McBride O. W., Korn E. D. The uptake of doubly labeled chylomicrons by guinea pig mammary gland and liver. J Lipid Res. 1964 Jul;5(3):459–467. [PubMed] [Google Scholar]
  19. Moskowitz M. S., Moskowitz A. A. Lipase: Localization in Adipose Tissue. Science. 1965 Jul 2;149(3679):72–73. doi: 10.1126/science.149.3679.72. [DOI] [PubMed] [Google Scholar]
  20. Olson A. C., Alaupovic P. Rat liver triglyceride lipase. Biochim Biophys Acta. 1966 Aug 3;125(1):185–187. doi: 10.1016/0005-2760(66)90159-7. [DOI] [PubMed] [Google Scholar]
  21. RASMUSSEN F., LINZELL J. L. THE ACCURACY OF THE INDICATOR ABSORPTION METHOD OF MEASURING MAMMARY BLOOD FLOW BY THE FICK PRINCIPLE. Q J Exp Physiol Cogn Med Sci. 1964 Apr;49:219–225. doi: 10.1113/expphysiol.1964.sp001722. [DOI] [PubMed] [Google Scholar]
  22. ROBINSON D. S. CHANGES IN THE LIPOLYTIC ACTIVITY OF THE GUINEA PIG MAMMARY GLAND AT PARTURITION. J Lipid Res. 1963 Jan;4:21–23. [PubMed] [Google Scholar]
  23. ROBINSON D. S., FRENCH J. E. Heparin, the clearing factor lipase, and fat transport. Pharmacol Rev. 1960 Jun;12:241–263. [PubMed] [Google Scholar]
  24. WASSERMANN F., McDONALD T. F. Electron microscopic study of adipose tissue (fat organs) with special reference to the transport of lipids between blood and fat cells. Z Zellforsch Mikrosk Anat. 1963;59:326–357. doi: 10.1007/BF00339791. [DOI] [PubMed] [Google Scholar]
  25. West C. E., Annison E. F., Linzell J. L. Mode of uptake of triglyceride by the goat mammary gland. Biochem J. 1967 Sep;104(3):59P–60P. [PMC free article] [PubMed] [Google Scholar]
  26. West C. E., Rowbotham T. R. The use of a computer in the determination by gas-liquid chromatography of the concentration and identification of individual fatty acids present as free fatty acids, triglycerides and cholesteryl esters. J Chromatogr. 1967 Sep;30(1):62–76. doi: 10.1016/s0021-9673(00)84113-8. [DOI] [PubMed] [Google Scholar]

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