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Review
. 2015 Sep;1(3):119-122.
doi: 10.1016/j.aninu.2015.08.008. Epub 2015 Sep 10.

Glutamine and Glutamate: Nonessential or Essential Amino Acids?

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Free PMC article
Review

Glutamine and Glutamate: Nonessential or Essential Amino Acids?

Malcolm Watford. Anim Nutr. .
Free PMC article

Abstract

Glutamine and glutamate are not considered essential amino acids but they play important roles in maintaining growth and health in both neonates and adults. Although glutamine and glutamate are highly abundant in most feedstuffs there is increasing evidence that they may be limiting during pregnancy, lactation and neonatal growth, particularly when relatively low protein diets are fed. Supplementation of diets with glutamine, glutamate or both at 0.5 to 1.0% to both suckling and recently weaned piglets improves intestinal and immune function and results in better growth. In addition such supplementation to the sow prevents some of the loss of lean body mass during lactation, and increases milk glutamine content. However, a number of important questions related to physiological condition, species under study and the form and amount of the supplements need to be addressed before the full benefits of glutamine and glutamate supplementation in domestic animal production can be realized.

Keywords: Amino acid; Glutamate; Glutamine; Growth; Lactation; Pregnancy.

Figures

Fig. 1
Fig. 1
Glutamine synthetase and glutaminase.
Fig. 2
Fig. 2
Pathways of glutamine and glutamate metabolism. The majority of glutamine is degraded to glutamate and then used as a substrate for urea and glucose synthesis or as a fuel (ATP production). Although glutamine is an essential precursor for many important compounds but these represent a small (<3%) fraction of glutamine metabolism. Glutamine also acts as an anabolic signal, often via activation of mammalian target of rapamycin (mTOR).
Fig. 3
Fig. 3
Glutamine metabolism during pregnancy and lactation. Increased dietary intake provides glutamine and glutamate for the small intestine, but skeletal muscle provides most of the circulating glutamine that is derived from other amino acids, including those from both the diet and muscle proteolysis. The size of the arrows indicates a rough estimate of the magnitude of glutamine flux.

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References

    1. Cabrera R.A., Usry J.L., Arrellano C., Nogueira E.T., Kutschenko M., Moeser A.J. Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets. J Anim Sci Biotech. 2013;4:29. - PMC - PubMed
    1. Clowes E.J., Aherne F.X., Baracos V.E. Skeletal muscle protein mobilization during the progression of lactation. Am J Physiol Endocrinol Metab. 2005;288:E564–E572. - PubMed
    1. Curthoys N.P., Watford M. Regulation of glutaminase activity and glutamine metabolism. Annu Rev Nutr. 1995;15:133–159. - PubMed
    1. Curi R., Newsholme P., Procopio J., Lagranha C., Gorjão R., Pithon-Curi T.C. Glutamine, gene expression, and cell function. Front Biosci. 2007 Jan 1;12:344–357. - PubMed
    1. Davis T.A., Nguyen H.V., Garcia-Bravo R., Fiorotto M.L., Jackson E.M., Reeds P.J. Amino acid composition of the milk of some mammalian species changes with stage of lactation. Br J Nutr. 1994;72:845–853. - PubMed

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