Enteroglucagon is a
peptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty am ...
hormone
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...
derived from
preproglucagon. It is a gastrointestinal hormone, secreted from
mucosal cells primarily of the
colon and terminal
ileum
The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may ...
. It consists of 37 amino acids. Enteroglucagon is released when fats and glucose are present in the small intestine; which decrease the motility to allow sufficient time for these nutrients to be absorbed.
Discovery
In 1948, Sutherland and De Duve identified a gastrointestinal glucagon-like material in gastric mucosa,
the term "enteroglucagon" was used to describe this material that shared a similar immunoreactivity with glucagon. A half-century later, Brubaker and Drucker studied
proglucagon gene expression, they discovered the function of enteroglucagon is related to the growth of intestinal epithelium.
Function
Enteroglucagon is a proglucagon-derived peptide or enteroendocrine cells derived peptide in the small intestine. Preproglucagon undergoes
post translational modification
In molecular biology, post-translational modification (PTM) is the covalent process of changing proteins following protein biosynthesis. PTMs may involve enzymes or occur spontaneously. Proteins are created by ribosomes, which translate mRNA in ...
to release glucagon-like peptides (GLP-1 and GLP-2) and other molecules derived from L-cells of intestine. GLP-1 is derived from a class of intestinal hormones called
incretin
Incretins are a group of metabolic hormones that decrease Blood sugar level, blood glucose levels. Incretins are released after eating and augment the secretion of insulin released from Pancreas, pancreatic beta cells of the islets of Langerhans ...
and the molecule exists in two forms GLP-1(7-37) and GLP-1(7-36) amide. GLP-1 form of incretin starts circulating in response to a high blood glucose level. Incretin effect is a
negative feedback loop between glucose and insulin level, it promotes insulin release from beta cells of pancreas islet and suppresses glucagon when the glucose level is high. In vertebrate mammals, GLP-2 sequences are highly conversed in the intestine.
The molecule functions as a part of adaptive response, such that contributes intestinal growth, proliferation effect, intestinal dilation (increases the mucosal blood flow) and reduces the chance of apoptosis.
Clinical significance
GLP-1 is effective at reducing blood glucose levels. GLP-1 analogs have a significant therapeutic effect and high efficacy on diabetes treatments and
hypoglycemia
Hypoglycemia (American English), also spelled hypoglycaemia or hypoglycæmia (British English), sometimes called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's tria ...
prevention. Proliferation effect and trophic effect on the small intestine, GLP-2 is used as a therapy to support patients with short-bowel syndrome and other underlying intestinal conditions.
See also
*
Proglucagon
References
External links
Overview at colostate.edu*
*
{{Hormones
Peptide hormones