Document Detail


Amino acid uptake by the mammary gland of the lactating ewe.
MedLine Citation:
PMID:  678219     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
(1) The arterio-venous difference technique, previously used to measure mammary substrate uptake with cows and goats, was used to measure amino acid uptake by the mammary gland of the lactating Merino ewe. Possession of a single large superficial epigastric vein by the Merino ewe makes the Merino breed the most suitable for this type of study. (2) A method was developed enabling hourly measurement of milk yield without causing undue stress. Milk yield was essentially constant over a 7-8 h period. (3) Mammary extraction of most non-essential amino acids was low relative to output in milk protein and showed a greater variability with time than that found for the essential amino acids. There was a significant mammary extraction of ornithine and citrulline, neither amino acid being found in ovine milk protein. (4) Of the essential amino acids valine, isoleucine, leucine and arginine were taken up in excess of their requirement for milk protein synthesis. (5) On the basis of the extent of mammary extraction, methionine, lysine and leucine were first-, second- and third-limiting to the rate of milk protein synthesis. (6) Despite fluctuations in arterial amino acid concentrations the arterio-venous differences of the essential amino acids were relatively constant over a 7-8 h period. (7) The pattern of mammary amino acid uptake in the ewe is contrasted with that found in similar studies carried out with the lactating cow and goat.
Authors:
S R Davis; R Bickerstaffe; D S Hart
Related Documents :
18931189 - A survey of commercially available broilers marketed as organic, free-range, and conven...
21316109 - Lipid mobilization and inflammatory responses during the transition period of dairy cows.
8920139 - Use of amino acid profiles of preterm and term human milks in evaluating scoring patter...
12494309 - Fatty acid and sn-2 fatty acid composition in human milk from granada (spain) and in in...
10750109 - Calf intestinal mucin: isolation, partial characterization, and measurement in ileal di...
7572739 - Erythrocyte and plasma cholesterol ester long-chain polyunsaturated fatty acids of low-...
20666529 - Modulation of homocysteine toxicity by s-nitrosothiol formation: a mechanistic approach.
23148559 - Exploiting the reversible covalent bonding of boronic acids: recognition, sensing, and ...
374639 - Interaction of group a streptococcal lipoteichoic acid with bovine myelin basic protein.
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Australian journal of biological sciences     Volume:  31     ISSN:  0004-9417     ISO Abbreviation:  Aust. J. Biol. Sci.     Publication Date:  1978 Apr 
Date Detail:
Created Date:  1978-09-30     Completed Date:  1978-09-30     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370613     Medline TA:  Aust J Biol Sci     Country:  AUSTRALIA    
Other Details:
Languages:  eng     Pagination:  123-32     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acids / metabolism*
Animals
Cattle
Female
Goats / metabolism
Lactation*
Mammary Glands, Animal / metabolism*
Methods
Milk / analysis,  secretion
Pregnancy
Secretory Rate
Sheep / metabolism*
Time Factors
Chemical
Reg. No./Substance:
0/Amino Acids

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Comparative toxicities of mimosine and some chemically related compounds to mouse bone marrow cells ...
Next Document:  Mammary glucose uptake in the lactating ewe and the use of methionine arterio-venous difference for ...