الفهرس 
Biochemical Structure and Metabolism of Glutamine
Chemical aspects of glutamineOnly 14 pages are availabe for public view
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Abstract
Glutamine (Gln) is an important energy source and has been
used as a supplementary energy substrate. Furthermore,
Gln is an essential component for numerous metabolic
functions, including acid-base homeostasis, gluconeogenesis,
nitrogen transport and synthesis of proteins and nucleic acids.
Therefore, glutamine plays a significant role in cell homeostasis
and organ metabolism.
It is known as a non-essential amino acid due to the
ability of most cells to produce it. Glutamine is present in the
plasma at levels around 0.6 mM and in the intracellular space
at levels around 2 and 20 mM. It also serves as a metabolic
intermediate, contributing carbon and nitrogen for the
synthesis of other amino acids, nucleic acids, fatty acids, and
proteins.
Glutamine is consumed predominantly in the
gastrointestinal tract as a source of energy, particularly under
the conditions of trauma, sepsis and surgery. Glutamine has a
unique role in the preservation of epithelial barrier function
in the gastrointestinal tract. Glutamine supplementation
protects the gastrointestinal mucosal homeostasis during total
parenteral nutrition, diarrhea, radiation injury, starvation,
sepsis and trauma.It plays multiple roles in the maintenance of
physiological homeostasis of diverse organs and cell types. It
is best known for its ability to serve as a source of fuel for
the cells such as enterocytes, renal epithelial cells,
hepatocytes, neurons, immune cells, Beta cells of pancreas.
Glutamine metabolism plays multiple roles in nitrogen
balance, regulation of glucose metabolism and acid base
homeostasis. It is quantitatively the most important donor of
ammonia in kidney and liver, and plays a role in maintaining
the acid-base balance of body fluids.
Parenteral glutamine administration is associated with
a decrease in infectious complications, decrease in hospital
length of stay, and possibly a decrease in mortality in
critically ill postoperative or ventilator dependent patients
requiring parenteral nutrition (PN). It may be beneficial in
certain other adult surgical patients, such as patients
undergoing major abdominal surgery, critically ill nonventilated patients, in adult burn patients or acute pancreatitis
patients who require PN.