Glutamine

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Glutamine
L-Glutamin - L-Glutamine.svg
Skeletal formula of L-glutamine
Glutamine-from-xtal-3D-bs-17.png
Glutamine-from-xtal-3D-sf.png
Sample of L-Glutamine.jpg
Names
IUPAC name
Glutamine
Other names
L-Glutamine
(levo)glutamide
2,5-Diamino-5-oxopentanoic acid
2-Amino-4-carbamoylbutanoic acid
Endari [1]
Identifiers
3D model (JSmol)
AbbreviationsGln, Q
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.266 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-292-1
KEGG
PubChem CID
UNII
  • InChI=1S/C5H10N2O3/c6-3(5(9)10)1-2-4(7)8/h3H,1-2,6H2,(H2,7,8)(H,9,10)/t3-/m0/s1 Yes check.svgY
    Key: ZDXPYRJPNDTMRX-VKHMYHEASA-N Yes check.svgY
  • O=C(N)CCC(N)C(=O)O
  • Zwitterion:O=C(N)CCC([NH3+])C(=O)[O-]
Properties [2]
C5H10N2O3
Molar mass 146.146 g·mol−1
Melting point decomposes around 185°C
soluble
Acidity (pKa)2.2 (carboxyl), 9.1 (amino)
+6.5º (H2O, c = 2)
Pharmacology
A16AA03 ( WHO )
Supplementary data page
Glutamine (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
L-glutamine oral powder
Clinical data
Trade names Endari, Nutrestore
AHFS/Drugs.com Monograph
MedlinePlus a617035
License data
Routes of
administration
By mouth
Drug class Gastrointestinal agent
ATC code
Legal status
Legal status
Identifiers
  • (S)-2,5-diamino-5-oxopentanoic acid
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
PDB ligand
CompTox Dashboard (EPA)
ECHA InfoCard 100.000.266 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C5H10N2O3
Molar mass 146.146 g·mol−1
3D model (JSmol)
  • C(CC(=O)N)C(C(=O)O)N
  • InChI=1S/C5H10N2O3/c6-3(5(9)10)1-2-4(7)8/h3H,1-2,6H2,(H2,7,8)(H,9,10)/t3-/m0/s1
  • Key:ZDXPYRJPNDTMRX-VKHMYHEASA-N
Data page
Glutamine (data page)

Glutamine (symbol Gln or Q) [3] is an α-amino acid that is used in the biosynthesis of proteins. Its side chain is similar to that of glutamic acid, except the carboxylic acid group is replaced by an amide. It is classified as a charge-neutral, polar amino acid. It is non-essential and conditionally essential in humans, meaning the body can usually synthesize sufficient amounts of it, but in some instances of stress, the body's demand for glutamine increases, and glutamine must be obtained from the diet. [4] [5] It is encoded by the codons CAA and CAG. It is named after glutamic acid, which in turn is named after its discovery in cereal proteins, gluten. [6]

In human blood, glutamine is the most abundant free amino acid. [7]

The dietary sources of glutamine include especially the protein-rich foods like beef, chicken, fish, dairy products, eggs, vegetables like beans, beets, cabbage, spinach, carrots, parsley, vegetable juices and also in wheat, papaya, Brussels sprouts, celery, kale and fermented foods like miso.

The one-letter symbol Q for glutamine was assigned in alphabetical sequence to N for asparagine, being larger by merely one methylene –CH2– group. Note that P was used for proline, and O was avoided due to similarity with D. The mnemonic Qlutamine was also proposed. [8]

Functions

Glutamine plays a role in a variety of biochemical functions:

Roles in metabolism

Glutamine maintains redox balance by participating in glutathione synthesis and contributing to anabolic processes such as lipid synthesis by reductive carboxylation. [16]

Glutamine provides a source of carbon and nitrogen for use in other metabolic processes. Glutamine is present in serum at higher concentrations than other amino acids [17] and is essential for many cellular functions. Examples include the synthesis of nucleotides and non-essential amino acids. [18] One of the most important functions of glutamine is its ability to be converted into α-KG, which helps to maintain the flow of the tricarboxylic acid cycle, generating ATP via the electron carriers NADH and FADH2. [19] The highest consumption of glutamine occurs in the cells of the intestines, [7] kidney cells (where it is used for acid-base balance), activated immune cells, [20] and many cancer cells. [9] [12] [21]

Production

Glutamine is produced industrially using mutants of Brevibacterium flavum , which gives ca. 40 g/L in 2 days using glucose as a carbon source. [22]

Biosynthesis

Glutamine synthesis from glutamate and ammonia is catalyzed by the enzyme glutamine synthetase. The majority of glutamine production occurs in muscle tissue, accounting for about 90% of all glutamine synthesized. Glutamine is also released, in small amounts, by the lungs and brain. [23] Although the liver is capable of glutamine synthesis, its role in glutamine metabolism is more regulatory than productive, as the liver takes up glutamine derived from the gut via the hepatic portal system. [7]

Uses

Nutrition

Glutamine is the most abundant naturally occurring, nonessential amino acid in the human body, and one of the few amino acids that can directly cross the blood–brain barrier. [7] Humans obtain glutamine through catabolism of proteins in foods they eat. [24] In states where tissue is being built or repaired, like growth of babies, or healing from wounds or severe illness, glutamine becomes conditionally essential. [24]

Sickle cell disease

In 2017, the U.S. Food and Drug Administration (FDA) approved L-glutamine oral powder, marketed as Endari, to reduce severe complications of sickle cell disease in people aged five years and older with the disorder. [1]

The safety and efficacy of L-glutamine oral powder were studied in a randomized trial of subjects ages five to 58 years old with sickle cell disease who had two or more painful crises within the 12 months prior to enrollment in the trial. [1] Subjects were assigned randomly to treatment with L-glutamine oral powder or placebo, and the effect of treatment was evaluated over 48 weeks. [1] Subjects who were treated with L-glutamine oral powder experienced fewer hospital visits for pain treated with a parenterally administered narcotic or ketorolac (sickle cell crises), on average, compared to subjects who received a placebo (median 3 vs. median 4), fewer hospitalizations for sickle cell pain (median 2 vs. median 3), and fewer days in the hospital (median 6.5 days vs. median 11 days). [1] Subjects who received L-glutamine oral powder also had fewer occurrences of acute chest syndrome (a life-threatening complication of sickle cell disease) compared with patients who received a placebo (8.6 percent vs. 23.1 percent). [1]

Common side effects of L-glutamine oral powder include constipation, nausea, headache, abdominal pain, cough, pain in the extremities, back pain and chest pain. [1]

L-glutamine oral powder received orphan drug designation. [1] The FDA granted the approval of Endari to Emmaus Medical Inc. [1]

Medical food

Glutamine is marketed as medical food and is prescribed when a medical professional believes a person in their care needs supplementary glutamine due to metabolic demands beyond what can be met by endogenous synthesis or diet. [25]

Safety

Glutamine is safe in adults and in preterm infants. [26] Although glutamine is metabolized to glutamate and ammonia, both of which have neurological effects, their concentrations are not increased much, and no adverse neurological effects were detected. [26] The observed safe level for supplemental L-glutamine in normal healthy adults is 14 g/day. [27]

Adverse effects of glutamine have been described for people receiving home parenteral nutrition and those with liver-function abnormalities. [28] Although glutamine has no effect on the proliferation of tumor cells, it is still possible that glutamine supplementation may be detrimental in some cancer types. [29]

Ceasing glutamine supplementation in people adapted to very high consumption may initiate a withdrawal effect, raising the risk of health problems such as infections or impaired integrity of the intestine. [29]

Structure

Glutamine can exist in either of two enantiomeric forms, L-glutamine and D-glutamine. The L-form is found in nature. Glutamine contains an α-amino group which is in the protonated −NH3+ form under biological conditions and a carboxylic acid group which is in the deprotonated −COO form, known as carboxylate, under physiological conditions.

Glutamine zwitterionic forms at neutral pH: L-glutamine (left) and D-glutamine Betain-Glutamin.png
Glutamine zwitterionic forms at neutral pH: L-glutamine (left) and D-glutamine

Research

Consequences of glutamine depletion in critically ill individuals BMRI2015-545467.001.jpg
Consequences of glutamine depletion in critically ill individuals

Glutamine mouthwash may be useful to prevent oral mucositis in people undergoing chemotherapy but intravenous glutamine does not appear useful to prevent mucositis in the GI tract. [31]

Glutamine supplementation was thought to have potential to reduce complications in people who are critically ill or who have had abdominal surgery but this was based on poor quality clinical trials. [32] Supplementation does not appear to be useful in adults or children with Crohn's disease or inflammatory bowel disease, but clinical studies as of 2016 were underpowered. [15] Supplementation does not appear to have an effect in infants with significant problems of the stomach or intestines. [33]

Some athletes use L-glutamine as supplement. Studies support the positive effects of the chronic oral administration of the supplement on the injury and inflammation induced by intense aerobic and exhaustive exercise, but the effects on muscle recovery from weight training are unclear. [34]

See also

Related Research Articles

α-Ketoglutaric acid Chemical compound

α-Ketoglutaric acid is a keto acid.

<span class="mw-page-title-main">Glutamic acid</span> Amino acid and neurotransmitter

Glutamic acid is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABAergic neurons.

<span class="mw-page-title-main">Isoleucine</span> Chemical compound

Isoleucine (symbol Ile or I) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH+3 form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a hydrocarbon side chain with a branch (a central carbon atom bound to three other carbon atoms). It is classified as a non-polar, uncharged (at physiological pH), branched-chain, aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it. Essential amino acids are necessary in the human diet. In plants isoleucine can be synthesized from threonine and methionine. In plants and bacteria, isoleucine is synthesized from pyruvate employing leucine biosynthesis enzymes. It is encoded by the codons AUU, AUC, and AUA.

<span class="mw-page-title-main">Lysine</span> Amino acid

Lysine is an α-amino acid that is a precursor to many proteins. It contains an α-amino group, an α-carboxylic acid group, and a side chain lysyl, classifying it as a basic, charged, aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the S configuration.

<span class="mw-page-title-main">Leucine</span> Chemical compound

Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a side chain isobutyl group, making it a non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Human dietary sources are foods that contain protein, such as meats, dairy products, soy products, and beans and other legumes. It is encoded by the codons UUA, UUG, CUU, CUC, CUA, and CUG. Leucine is named after the Greek word for "white": λευκός (leukós, "white"), after its common appearance as a white powder, a property it shares with many other amino acids.

<span class="mw-page-title-main">Arginine</span> Amino acid

Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2) and both the amino and guanidino groups are protonated, resulting in a cation. Only the l-arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is encoded by the codons CGU, CGC, CGA, CGG, AGA, and AGG. The guanidine group in arginine is the precursor for the biosynthesis of nitric oxide. Like all amino acids, it is a white, water-soluble solid.

<span class="mw-page-title-main">Ornithine</span> Chemical compound

Ornithine is a non-proteinogenic α-amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl.

<span class="mw-page-title-main">Glutamate dehydrogenase</span> Hexameric enzyme

Glutamate dehydrogenase is an enzyme observed in both prokaryotes and eukaryotic mitochondria. The aforementioned reaction also yields ammonia, which in eukaryotes is canonically processed as a substrate in the urea cycle. Typically, the α-ketoglutarate to glutamate reaction does not occur in mammals, as glutamate dehydrogenase equilibrium favours the production of ammonia and α-ketoglutarate. Glutamate dehydrogenase also has a very low affinity for ammonia, and therefore toxic levels of ammonia would have to be present in the body for the reverse reaction to proceed. However, in brain, the NAD+/NADH ratio in brain mitochondria encourages oxidative deamination. In bacteria, the ammonia is assimilated to amino acids via glutamate and aminotransferases. In plants, the enzyme can work in either direction depending on environment and stress. Transgenic plants expressing microbial GLDHs are improved in tolerance to herbicide, water deficit, and pathogen infections. They are more nutritionally valuable.

In molecular biology, biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism.

<span class="mw-page-title-main">Glutamine synthetase</span> Class of enzymes

Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine:

<span class="mw-page-title-main">Branched-chain amino acid</span> Amino acid with a branched carbon chain

A branched-chain amino acid (BCAA) is an amino acid having an aliphatic side-chain with a branch. Among the proteinogenic amino acids, there are three BCAAs: leucine, isoleucine, and valine. Non-proteinogenic BCAAs include 2-aminoisobutyric acid and alloisoleucine.

<span class="mw-page-title-main">Sodium phenylbutyrate</span> Chemical compound

Sodium phenylbutyrate, sold under the brand name Buphenyl among others, is a salt of an aromatic fatty acid, 4-phenylbutyrate (4-PBA) or 4-phenylbutyric acid. The compound is used to treat urea cycle disorders, because its metabolites offer an alternative pathway to the urea cycle to allow excretion of excess nitrogen.

<span class="mw-page-title-main">Glutaminase</span>

Glutaminase is an amidohydrolase enzyme that generates glutamate from glutamine. Glutaminase has tissue-specific isoenzymes. Glutaminase has an important role in glial cells.

<span class="mw-page-title-main">Phenylacetylglutamine</span> Chemical compound

Phenylacetylglutamine is a product formed by the conjugation of phenylacetate and glutamine. It is a common metabolite that occurs naturally in human urine.

Glutaminolysis (glutamine + -lysis) is a series of biochemical reactions by which the amino acid glutamine is lysed to glutamate, aspartate, CO2, pyruvate, lactate, alanine and citrate.

α-Ketoisocaproic acid Chemical compound

α-Ketoisocaproic acid (α-KIC), also known as 4-methyl-2-oxovaleric acid, and its conjugate base and carboxylate, α-ketoisocaproate, are metabolic intermediates in the metabolic pathway for L-leucine. Leucine is an essential amino acid, and its degradation is critical for many biological duties. α-KIC is produced in one of the first steps of the pathway by branched-chain amino acid aminotransferase by transferring the amine on L-leucine onto alpha ketoglutarate, and replacing that amine with a ketone. The degradation of L-leucine in the muscle to this compound allows for the production of the amino acids alanine and glutamate as well. In the liver, α-KIC can be converted to a vast number of compounds depending on the enzymes and cofactors present, including cholesterol, acetyl-CoA, isovaleryl-CoA, and other biological molecules. Isovaleryl-CoA is the main compound synthesized from ɑ-KIC. α-KIC is a key metabolite present in the urine of people with Maple syrup urine disease, along with other branched-chain amino acids. Derivatives of α-KIC have been studied in humans for their ability to improve physical performance during anaerobic exercise as a supplemental bridge between short-term and long-term exercise supplements. These studies show that α-KIC does not achieve this goal without other ergogenicsupplements present as well. α-KIC has also been observed to reduce skeletal muscle damage after eccentrically biased resistance exercises in people who do not usually perform those exercises.

In biochemistry, the glutamate–glutamine cycle is a cyclic metabolic pathway which maintains an adequate supply of the neurotransmitter glutamate in the central nervous system. Neurons are unable to synthesize either the excitatory neurotransmitter glutamate, or the inhibitory GABA from glucose. Discoveries of glutamate and glutamine pools within intercellular compartments led to suggestions of the glutamate–glutamine cycle working between neurons and astrocytes. The glutamate/GABA–glutamine cycle is a metabolic pathway that describes the release of either glutamate or GABA from neurons which is then taken up into astrocytes. In return, astrocytes release glutamine to be taken up into neurons for use as a precursor to the synthesis of either glutamate or GABA.

<span class="mw-page-title-main">Purine nucleotide cycle</span>

The Purine Nucleotide Cycle is a metabolic pathway in protein metabolism requiring the amino acids aspartate and glutamate. The cycle is used to regulate the levels of adenine nucleotides, in which ammonia and fumarate are generated. AMP converts into IMP and the byproduct ammonia. IMP converts to S-AMP (adenylosuccinate), which then converts to AMP and the byproduct fumarate. The fumarate goes on to produce ATP (energy) via oxidative phosphorylation as it enters the Krebs cycle and then the electron transport chain. Lowenstein first described this pathway and outlined its importance in processes including amino acid catabolism and regulation of flux through glycolysis and the Krebs cycle.

Juven is a medical food that is manufactured by Abbott Laboratories and used to provide nutritional support under the care of a physician in individuals with muscle wasting due to AIDS or cancer, to promote wound healing following surgery or injury, or when otherwise recommended by a medical professional. It is a powdered nutritional supplement that contains 3 grams of calcium β-hydroxy β-methylbutyrate, 14 grams of L-arginine, and 14 grams of L-glutamine per two daily servings.

<span class="mw-page-title-main">Alanyl-glutamine</span> Chemical compound

Alanyl-glutamine is a chemical compound which in the form L-alanyl-L-glutamine is used in dietary supplementation, in parenteral nutrition, and in cell culture. It is a dipeptide consisting of alanine and glutamine.

References

  1. 1 2 3 4 5 6 7 8 9 "FDA approves new treatment for sickle cell disease". U.S. Food and Drug Administration (FDA) (Press release). 7 July 2017. Retrieved 10 July 2017.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  2. Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-311. ISBN   0-8493-0462-8..
  3. "Nomenclature and Symbolism for Amino Acids and Peptides". IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. Archived from the original on 9 October 2008. Retrieved 5 March 2018.
  4. Food and Nutrition Board of the Institute of Medicine (2006). "Protein and Amino Acids". In Otten JJ, Hellwig JP, Meyers LD (eds.). Dietary Reference Intakes: The Essential Guide to Nutrient Requirements (PDF). Washington, D.C.: National Academies Press. p. 147. ISBN   978-0-309-10091-5. Archived from the original (PDF) on 9 March 2014.
  5. Lacey JM, Wilmore DW (August 1990). "Is glutamine a conditionally essential amino acid?". Nutrition Reviews. 48 (8): 297–309. doi:10.1111/j.1753-4887.1990.tb02967.x. PMID   2080048.
  6. Saffran, M. (April 1998). "Amino acid names and parlor games: from trivial names to a one-letter code, amino acid names have strained students' memories. Is a more rational nomenclature possible?". Biochemical Education. 26 (2): 116–118. doi:10.1016/s0307-4412(97)00167-2. ISSN   0307-4412.
  7. 1 2 3 4 5 Brosnan JT (June 2003). "Interorgan amino acid transport and its regulation". The Journal of Nutrition. 133 (6 Suppl 1): 2068S–2072S. doi: 10.1093/jn/133.6.2068S . PMID   12771367. Open Access logo PLoS transparent.svg
  8. Saffran, M. (April 1998). "Amino acid names and parlor games: from trivial names to a one-letter code, amino acid names have strained students' memories. Is a more rational nomenclature possible?". Biochemical Education. 26 (2): 116–118. doi:10.1016/S0307-4412(97)00167-2.
  9. 1 2 Corbet C, Feron O (July 2015). Corbet C, Feron O (eds.). "Metabolic and mind shifts: from glucose to glutamine and acetate addictions in cancer". Current Opinion in Clinical Nutrition and Metabolic Care. 18 (4): 346–353. doi:10.1097/MCO.0000000000000178. PMID   26001655. S2CID   1478014.
  10. Hall JE, Guyton AC (2006). Textbook of Medical Physiology (11th ed.). St. Louis, Mo: Elsevier Saunders. p. 393. ISBN   978-0-7216-0240-0.
  11. Aledo JC (July 2004). "Glutamine breakdown in rapidly dividing cells: waste or investment?". BioEssays. 26 (7): 778–785. doi:10.1002/bies.20063. PMID   15221859.
  12. 1 2 Yuneva M, Zamboni N, Oefner P, Sachidanandam R, Lazebnik Y (July 2007). "Deficiency in glutamine but not glucose induces MYC-dependent apoptosis in human cells". The Journal of Cell Biology. 178 (1): 93–105. doi:10.1083/jcb.200703099. PMC   2064426 . PMID   17606868.
  13. Zielińska, Magdalena; Albrecht, Jan; Popek, Mariusz (2022). "Dysregulation of Astrocytic Glutamine Transport in Acute Hyperammonemic Brain Edema". Frontiers in Neuroscience. 16: 874750. doi: 10.3389/fnins.2022.874750 . ISSN   1662-4548. PMC   9207324 . PMID   35733937.
  14. Dabrowska K, Skowronska K, Popek M, Obara-Michlewska M, Albrecht J, Zielinska M (2018). "Roles of Glutamate and Glutamine Transport in Ammonia Neurotoxicity: State of the Art and Question Marks". Endocrine, Metabolic & Immune Disorders Drug Targets. 18 (4): 306–315. doi:10.2174/1871520618666171219124427. PMID   29256360. S2CID   26569656.
  15. 1 2 Yamamoto T, Shimoyama T, Kuriyama M (April 2017). "Dietary and enteral interventions for Crohn's disease". Current Opinion in Biotechnology. 44: 69–73. doi:10.1016/j.copbio.2016.11.011. PMID   27940405.
  16. Jiang L, Shestov AA, Swain P, Yang C, Parker SJ, Wang QA, et al. (April 2016). "Reductive carboxylation supports redox homeostasis during anchorage-independent growth". Nature. 532 (7598): 255–258. Bibcode:2016Natur.532..255J. doi:10.1038/nature17393. PMC   4860952 . PMID   27049945.
  17. Welbourne TC (March 1979). "Ammonia production and glutamine incorporation into glutathione in the functioning rat kidney". Canadian Journal of Biochemistry. 57 (3): 233–237. doi:10.1139/o79-029. PMID   436006.
  18. DeBerardinis RJ, Mancuso A, Daikhin E, Nissim I, Yudkoff M, Wehrli S, Thompson CB (December 2007). "Beyond aerobic glycolysis: transformed cells can engage in glutamine metabolism that exceeds the requirement for protein and nucleotide synthesis". Proceedings of the National Academy of Sciences of the United States of America. 104 (49): 19345–19350. Bibcode:2007PNAS..10419345D. doi: 10.1073/pnas.0709747104 . PMC   2148292 . PMID   18032601.
  19. DeBerardinis RJ, Lum JJ, Hatzivassiliou G, Thompson CB (January 2008). "The biology of cancer: metabolic reprogramming fuels cell growth and proliferation". Cell Metabolism. 7 (1): 11–20. doi: 10.1016/j.cmet.2007.10.002 . PMID   18177721.
  20. Newsholme P (September 2001). "Why is L-glutamine metabolism important to cells of the immune system in health, postinjury, surgery or infection?". The Journal of Nutrition. 131 (9 Suppl): 2515S–2522S, discussion 2522S–4S. doi: 10.1093/jn/131.9.2515S . PMID   11533304.
  21. Fernandez-de-Cossio-Diaz J, Vazquez A (October 2017). "Limits of aerobic metabolism in cancer cells". Scientific Reports. 7 (1): 13488. Bibcode:2017NatSR...713488F. doi:10.1038/s41598-017-14071-y. PMC   5647437 . PMID   29044214.
  22. Drauz K, Grayson I, Kleemann A, Krimmer HP, Leuchtenberger W, Weckbecker C (2007). "Amino Acids". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a02_057.pub2. ISBN   978-3527306732.
  23. Newsholme P, Lima MM, Procopio J, Pithon-Curi TC, Doi SQ, Bazotte RB, Curi R (February 2003). "Glutamine and glutamate as vital metabolites". Brazilian Journal of Medical and Biological Research = Revista Brasileira de Pesquisas Medicas e Biologicas. 36 (2): 153–163. doi: 10.1590/S0100-879X2003000200002 . PMID   12563517.
  24. 1 2 Watford M (September 2015). "Glutamine and glutamate: Nonessential or essential amino acids?". Animal Nutrition. 1 (3): 119–122. doi:10.1016/j.aninu.2015.08.008. PMC   5945979 . PMID   29767158.
  25. "GlutaSolve, NutreStore, SYMPT-X G.I., SYMPT-X Glutamine (glutamine) Drug Side Effects, Interactions, and Medication Information on eMedicineHealth". eMedicineHealth. Retrieved 24 January 2017.
  26. 1 2 Garlick PJ (September 2001). "Assessment of the safety of glutamine and other amino acids". The Journal of Nutrition. 131 (9 Suppl): 2556S–2561S. doi: 10.1093/jn/131.9.2556S . PMID   11533313.
  27. Shao A, Hathcock JN (April 2008). "Risk assessment for the amino acids taurine, L-glutamine and L-arginine". Regulatory Toxicology and Pharmacology. 50 (3): 376–399. doi:10.1016/j.yrtph.2008.01.004. PMID   18325648.
  28. Buchman AL (July 2001). "Glutamine: commercially essential or conditionally essential? A critical appraisal of the human data". The American Journal of Clinical Nutrition. 74 (1): 25–32. doi: 10.1093/ajcn/74.1.25 . PMID   11451714.
  29. 1 2 Holecek M (September 2013). "Side effects of long-term glutamine supplementation". Journal of Parenteral and Enteral Nutrition. 37 (5): 607–616. doi:10.1177/0148607112460682. PMID   22990615.
  30. Stehle P, Kuhn KS (2015). "Glutamine: an obligatory parenteral nutrition substrate in critical care therapy". BioMed Research International. 2015: 545467. doi: 10.1155/2015/545467 . PMC   4606408 . PMID   26495301.
  31. Berretta M, Michieli M, Di Francia R, Cappellani A, Rupolo M, Galvano F, et al. (January 2013). "Nutrition in oncologic patients during antiblastic treatment". Frontiers in Bioscience. 18 (1): 120–132. doi: 10.2741/4091 . PMID   23276913.
  32. Tao KM, Li XQ, Yang LQ, Yu WF, Lu ZJ, Sun YM, Wu FX (September 2014). "Glutamine supplementation for critically ill adults". The Cochrane Database of Systematic Reviews. 2018 (9): CD010050. doi:10.1002/14651858.CD010050.pub2. PMC   6517119 . PMID   25199493.
  33. Moe-Byrne T, Brown JV, McGuire W (April 2016). McGuire W (ed.). "Glutamine supplementation to prevent morbidity and mortality in preterm infants". The Cochrane Database of Systematic Reviews. 4 (4): CD001457. doi:10.1002/14651858.CD001457.pub6. PMC   7055588 . PMID   27089158.
  34. Raizel R, Tirapegui J (5 December 2018). "Role of glutamine, as free or dipeptide form, on muscle recovery from resistance training: a review study". Nutrire. 43 (1): 28. doi: 10.1186/s41110-018-0087-9 . ISSN   2316-7874. S2CID   81105808.