Glutamine
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Chemical structure of L-glutamine
Systematic name
(2S)-2-amino-4-carbamoyl-butanoic acid
Chemical formula
C 5
H 10 N 2
O 3
Molar mass
146.15 g mol−1
Complete data
Glutamine (Gln) is one of the 20
amino acids encoded by the
standard genetic code. Its
side chain is an
amide; it is formed by replacing
a side-chain hydroxyl of
glutamic acid with an
amine
functional group.
Contents
Biochemistry
Formation and Nomenclature
Glutamine is genetically coded
for by the RNA
codons CAA and CAG. Glutamine's
three-letter abbreviation is Gln, and its one-letter abbreviation is Q.
A three-letter designation for either glutamine or glutamic acid is Glx (one-letter
abbreviation: Z).
Like other amino acids, glutamine is
biochemically important
as a constituent of proteins.
Glutamine is also crucial in nitrogen
metabolism.
Ammonia (formed by
nitrogen fixation)
is assimilated into organic
compounds by converting glutamic acid to glutamine. The
enzyme that accomplishes this
is called glutamine
synthetase. Glutamine can, hence, be used as a nitrogen donor in the biosynthesis
of many compounds, including other amino acids,
purines, and
pyrimidines.
Nutrition
Occurrences in Nature
Glutamine is found in foods high in proteins, such as fish, red meat, beans,
and dairy products.
Use
Glutamine is a supplement that is used in
weightlifting,
bodybuilding,
endurance
and other sports, as well as by those who suffer from
muscular cramps or pain�particularly
elderly people. It has been shown to speed up the
Krebs Cycle, aiding in weight
loss while retaining muscle[citation
needed]. The main use of glutamine within the
diet of either group
is as a means of replenishing the body's stores of amino acids that have been used
during exercise or everyday activities.
Studies which are looking into problems with excessive consumption of glutamine
thus far have proved inconclusive. However, normal supplementation is healthy mainly
because glutamine is supposed to be supplemented after prolonged periods of exercise
(for example, a workout or exercise in which amino acids are required for use) and
replenishes amino acid stores; this being the main reason glutamine is recommended
during fasting or for people who suffer from
physical trauma,
immune deficiencies,
or cancer.[1]
Aiding gastrointestinal function
There have been several recent studies into the effects of glutamine and what
properties it possesses, and, there is now a significant body of evidence that links
glutamine-enriched diets with intestinal effects; aiding maintenance of
gut
barrier function, intestinal
cell
proliferation and
differentiation,
as well as generally reducing
septic morbidity and the symptoms of
Irritable Bowel
Syndrome. The reason for such "cleansing" properties is thought to stem from
the fact that the intestinal extraction rate of glutamine is higher than that for
other amino acids, and is therefore thought to be the most viable option when attempting
to alleviate conditions relating to the
gut. [1]
These conditions were discovered after comparing plasma concentration within
the gut between glutamine-enriched and non glutamine-enriched diets. However, even
though glutamine is thought to have "cleansing" properties and effects, it is unknown
to what extent glutamine has clinical benefits, due to the varied concentrations
of glutamine in varieties of food. [1]
Aiding recovery after surgery
It is also known that glutamine has various effects in reducing
healing time after operations.
Hospital waiting times after abdominal
surgery are reduced by providing
parenteral nutrition
regimens containing amounts of glutamine to patients. Clinical trials have revealed
that patients on supplementation regimes containing glutamine have improved nitrogen
balances, generation of cysteinyl-leukotrienes
from polymorphonuclear
neutrophil granulocytes and improved
lymphocyte recovery and intestinal
permeability (in postoperative patients) - in comparison to those who had no glutamine
within their dietary regime; all without any
side-effects.
[3]
See also
References
- ^
Glutamine
used for the Immune System and Cancer. Retrieved on
2006-07-28.
- a
b
Boza J.J., Dangin M., Moennoz D., Montigon F., Vuichoud J., Jarret A., Pouteau
E., Gremaud G., Oguey-Araymon S., Courtois D., Woupeyi A., Finot P.A. and Ballevre
O. Free and protein-bound glutamine have identical splanchnic extraction in
healthy human volunteers. Am J Physiol Gastrointest Liver Physiol. 2001 Jul;
281(1): G267-74.
PMID 11408280
Free text
- a McAnena O.J., Moore
F.A., Moore E.E., Jones T.N. and Parsons P. Selective uptake of glutamine in
the gastrointestinal tract: confirmation in a human study. Br J Surg. 1991
Apr; 78(4): 480-2.
PMID 1903318
- a Morlion B.J., Stehle
P., Wachtler P., Siedhoff H.P., Koller M., Konig W., Furst P., Puchstein C.
Total parenteral nutrition with glutamine dipeptide after major abdominal surgery.
Ann Surg. 1998 Feb; 227(2): 302-8.
PMID 9488531
- a Jiang Z.M., Cao J.D.,
Zhu X.G., Zhao W.X., Yu J.C., Ma E.L., Wang X.R., Zhu M.W., Shu H., Liu Y.W.
The impact of alanyl-glutamine on clinical safety, nitrogen balance, intestinal
permeability, and clinical outcome in postoperative patients: a randomised,
double-blind, controlled study of 120 patients. JPEN J Parenter Enteral Nutr.
1999 Sep-Oct;23(5 Suppl):S62-6.
PMID 10483898
External links
The 20 Common Amino Acids
Alanine (dp)
| Arginine (dp)
| Asparagine (dp)
| Aspartic acid (dp)
| Cysteine (dp)
| Glutamic acid (dp)
| Glutamine (dp)
| Glycine (dp)
| Histidine (dp)
| Isoleucine (dp)
| Leucine (dp)
| Lysine (dp)
| Methionine (dp)
| Phenylalanine (dp)
| Proline (dp)
| Serine (dp)
| Threonine (dp)
| Tryptophan (dp)
| Tyrosine (dp)
| Valine (dp)
Articles about vitamins
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