Changes in glutamine metabolism indicate a mild catabolic state in the transition mare.
Abstract: Glutamine is the most abundant free alpha-AA in the mammalian body, and large amounts of glutamine are extracted by both the fetus during pregnancy and the mammary gland during lactation. The work presented here addressed the hypothesis that there would be major changes in glutamine metabolism in the mare during the transition period, the time between late gestation, parturition, and early lactation. Eight foals were born to Standardbred mares provided with energy and protein at 10% above NRC recommendations, and foals remained with mares for 6 mo. During lactation, lean body mass decreased by 1.5% (P < 0.05), whereas fat mass was unchanged throughout gestation and lactation. There was a sharp increase in the concentration of most plasma metabolites and hormones after birth, which was due in part to hemoconcentration because of fluid shifts at parturition. Plasma glutamine concentration, however, was maintained at greater concentrations for up to 2 wk postpartum but then began to decrease, reaching a nadir at approximately 6 wk of lactation. Skeletal muscle glutamine content did not change, but glutamine synthetase expression was decreased at the end of lactation (P < 0.05). Free glutamine was highly abundant in milk early in lactation, but the concentration decreased by more than 50% after 3 mo of lactation and paralleled the decrease in plasma glutamine concentration. Thus, lactation represents a mild catabolic state for the mare in which decreased glutamine concentrations may compromise the availability of glutamine to other tissues such as the intestines and the immune system.
Publication Date: 2008-11-28 PubMed ID: 19036697DOI: 10.2527/jas.2008-1054Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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This research study investigates how glutamine metabolism in mares changes during the transition period from late pregnancy through parturition (birth) and into early lactation. It reveals that lactation presents a mild catabolic state where decreased glutamine levels may affect other tissues like the intestines and immune system.
Research Context
- Glutamine is the most prevalent free amino acid in the mammalian body, significantly absorbed by the fetus during pregnancy and the mammary gland during lactation periods.
- The transition period, a phase involving late pregnancy, birth, and early lactation, is theorized to greatly affect glutamine metabolism in mares.
- Eight foals born to standardbred mares that received energy and protein 10% above the National Research Council (NRC) recommendations were the central focus of this study. The foals stayed with their mothers for six months.
Research Observations
- During lactation, the mares’ lean body mass reduced by 1.5% while the fat mass remained unchanged throughout the gestation and lactation periods.
- There was a substantial increase in the concentration of most plasma metabolites and hormones postpartum which was partly due to increased hemoconcentration from fluid shifts at parturition.
- The plasma concentration of glutamine was maintained at higher levels up to 2 weeks postpartum, but started to decrease afterwards, hitting the lowest point around the 6th week of lactation.
- Glutamine content in skeletal muscle stayed constant, but glutamine synthetase expression decreased at the end of the lactation period.
Research Findings
- Glutamine was found in high abundance in milk in early lactation. However, its concentration reduced by over 50% after 3 months of lactation, which paralleled the decrease in the plasma glutamine concentration.
- This data suggests that lactation denotes a mild catabolic state for the mare, with declining glutamine levels that may negatively impact other tissues such as the intestines and immune system.
Cite This Article
APA
Manso Filho HC, McKeever KH, Gordon ME, Costa HE, Lagakos WS, Watford M.
(2008).
Changes in glutamine metabolism indicate a mild catabolic state in the transition mare.
J Anim Sci, 86(12), 3424-3431.
https://doi.org/10.2527/jas.2008-1054 Publication
Researcher Affiliations
- Department of Animal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
MeSH Terms
- Animals
- Body Composition / physiology
- Female
- Glutamate-Ammonia Ligase / metabolism
- Glutamine / analysis
- Glutamine / metabolism
- Horses / metabolism
- Hydrocortisone / blood
- Insulin / blood
- Leptin / blood
- Milk / chemistry
- Muscle, Skeletal / enzymology
- Muscle, Skeletal / metabolism
- Parturition / physiology
- Pregnancy
- Time Factors
Citations
This article has been cited 4 times.- Salari F, Roncoroni C, Altomonte I, Boselli C, Brajon G, Martini M. Effects of the Physiological Status and Diet on Blood Metabolic Parameters in Amiata Dairy Donkeys. Animals (Basel) 2021 Nov 17;11(11).
- Watford M. Glutamine and glutamate: Nonessential or essential amino acids?. Anim Nutr 2015 Sep;1(3):119-122.
- Manso HE, Filho HC, de Carvalho LE, Kutschenko M, Nogueira ET, Watford M. Glutamine and glutamate supplementation raise milk glutamine concentrations in lactating gilts. J Anim Sci Biotechnol 2012 Feb 28;3(1):2.
- Le H, Nguyen M, Manso HEC, Wang MD, Watford M. Adipocytes Are the Only Site of Glutamine Synthetase Expression Within the Lactating Mouse Mammary Gland. Curr Dev Nutr 2024 Jun;8(6):102168.
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