Abstract
1. Total α-amino N and the amounts of 24 ninhydrin-positive substances were determined in several samples of plasma and lymph from the cow's udder. The arteriovenous differences of these substances across the mammary glands were measured in several experiments performed on lactating cows and in one experiment on a `dry' cow. Udder lymph obtained from live lactating cows by a lymph fistula and taken after killing lactating cows was analysed. 2. The concentrations of the individual free amino acids in udder lymph obtained from the live cow were similar to those found in cow's plasma. The concentrations of many amino acids in udder lymph taken immediately after death were two- to four-fold higher than those of the corresponding amino acids in udder lymph obtained from the live cow. 3. Most amino acids of the blood showed a considerable decrease in concentration by passage across the lactating mammary gland. Ornithine, a non-casein amino acid, showed arteriovenous differences of up to 60% of the arterial plasma concentration. No substantial amino acid uptake by the udder could be demonstrated in the experiment on the non-lactating cow. 4. The arteriovenous differences obtained for arginine, glutamine, isoleucine, leucine, lysine, valine, threonine and histidine were probably large enough to provide all the respective amino acid residues in milk protein. 5. The uptake of aspartic acid, asparagine, glutamic acid, serine and proline by the lactating cow's udder was not sufficient to account for all these respective amino acid residues found in milk protein.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- ASKONAS B. A., CAMPBELL P. N., GODIN C., WORK T. S. Biosynthesis of proteins. 3. Precursors in the synthesis of casein and beta-lactoglobulin. Biochem J. 1955 Sep;61(1):105–115. doi: 10.1042/bj0610105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ASKONAS B. A., CAMPBELL P. N., WORK T. S. The biosynthesis of proteins. II. Synthesis of milk proteins by the goat. Biochem J. 1954 Oct;58(2):326–331. doi: 10.1042/bj0580326. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BARRY J. M. The source of lysine, tyrosine, and phosphorus for casein synthesis. J Biol Chem. 1952 Apr;195(2):795–803. [PubMed] [Google Scholar]
- BARRY J. M. The source of proline for casein biosynthesis. Biochem J. 1958 Oct;70(2):177–179. doi: 10.1042/bj0700177a. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BARRY J. M. The use of glutamine and glutamic acid by the mammary gland for casein synthesis. Biochem J. 1956 Aug;63(4):669–676. doi: 10.1042/bj0630669. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BARRY J. M. The use of glutamine and glutamic acid by the mammary gland for casein synthesis. Biochem J. 1956 Aug;63(4):669–676. doi: 10.1042/bj0630669. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BETKE K., SAVELSBERG W. Stufenphotometrische Hämoglobinbestimmung mittels Cyanhämiglobin. Biochem Z. 1950;320(5):431–439. [PubMed] [Google Scholar]
- BOUCKAERT J. H., OYAERT W., PEETERS G., SIERENS G. Uptake of plasma amino acids by the perfused isolated cow's udder. Arch Int Pharmacodyn Ther. 1953 Apr;93(3-4):443–449. [PubMed] [Google Scholar]
- Blackwood J. H. The absorption of milk precursors by the mammary gland: The relation of amino-acid absorption to protein synthesis. Biochem J. 1932;26(3):772–777. doi: 10.1042/bj0260772. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CAMPBELL P. N., WORK T. S. The Biosynthesis of Protein. I. Uptake of glycine, serine, valine and lysine by the mammary gland of the rabbit. Biochem J. 1952 Oct;52(2):217–227. doi: 10.1042/bj0520217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CHINARD F. P. Photometric estimation of proline and ornithine. J Biol Chem. 1952 Nov;199(1):91–95. [PubMed] [Google Scholar]
- HEYNDRICKX G. V. Nitrogenous substances in udder lymph and plasma of cattle. Am J Physiol. 1961 Apr;200:835–837. doi: 10.1152/ajplegacy.1961.200.4.835. [DOI] [PubMed] [Google Scholar]
- LINZELL J. L. Mammary-gland blood flow and oxygen, glucose and volatile fatty acid uptake in the conscious goat. J Physiol. 1960 Oct;153:492–509. doi: 10.1113/jphysiol.1960.sp006550. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- MARKO A. M. The chromatographic determination of glutamic, aspartic, and cysteic acids using and anion exchange resin. Can J Biochem Physiol. 1957 Dec;35(12):1249–1258. [PubMed] [Google Scholar]
- MOORE S., STEIN W. H. Procedures for the chromatographic determination of amino acids on four per cent cross-linked sulfonated polystyrene resins. J Biol Chem. 1954 Dec;211(2):893–906. [PubMed] [Google Scholar]
- PEETERS G., COCQUYT G., DEMOOR A. L''ECOULEMENT DE LA LYMPHE DE LA GLANDE MAMMAIRE CHEZ LA VACHE LAITI'ERE. Ann Endocrinol (Paris) 1963 Jul-Aug;24:717–718. [PubMed] [Google Scholar]
- RAAFAT M. A., VERBEKE R., PEETERS G. The metabolism of propionate in the isolated cow's udder. Biochem J. 1963 Jul;88:155–159. doi: 10.1042/bj0880155. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SANSOM B. F., BARRY J. M. The use of asparagine and glutamine for the biosynthesis of casein and plasma proteins. Biochem J. 1958 Mar;68(3):487–493. doi: 10.1042/bj0680487. [DOI] [PMC free article] [PubMed] [Google Scholar]
- STEIN W. H., MOORE S. The free amino acids of human blood plasma. J Biol Chem. 1954 Dec;211(2):915–926. [PubMed] [Google Scholar]
- VERBEKE R., AQVIST S., PEETERS G. Acetate and propionate as precursors of amino-acids in milk proteins of the perfused cow's udder. Arch Int Physiol Biochim. 1957 Sep;65(3):433–438. doi: 10.3109/13813455709069427. [DOI] [PubMed] [Google Scholar]
- VERBEKE R., PEETERS G. The synthesis of amino acids by the perfused cow udder. Biochim Biophys Acta. 1960 Jan 29;37:533–534. doi: 10.1016/0006-3002(60)90514-x. [DOI] [PubMed] [Google Scholar]
- WOOD H. G., GILLESPIE R., JOFFE S., HANSEN R. G., HARDENBROOK H. Lactose synthesis. V. C14 in lactose, glycerol, and serine as indicators of the triose phosphate isomerase reaction and pentose cycle. J Biol Chem. 1958 Dec;233(6):1271–1278. [PubMed] [Google Scholar]