Gastrointestinal hormone
Encyclopedia
The gastrointestinal hormones (or gut hormones) constitute a group of hormone
s secreted by enteroendocrine cells in the stomach
, pancreas
, and small intestine
that control various functions of the digestive organs. Later
studies showed that most of the gut peptides, such as secretin
, cholecystokinin
or substance P
, were found to play a role of neurotransmitter
s and neuromodulators in the central and peripheral nervous systems.
Enteroendocrine cells do not form endocrine glands but are spread throughout the digestive tract. They exert their autocrine and paracrine actions that integrate all of gastrointestinal function.
.
Ghrelin is a peptide hormone released from the stomach and is often referred to as the "hunger hormone" since high levels of it are found in individuals that are fasting. Ghrelin antagonistic treatments can be used to treat illnesses such as anorexia and loss of appetites in cancer patients. Ghrelin treatments for obesity are still under intense scrutiny and no conclusive evidence has been reached. This hormone stimulates growth hormone release.
Cholecystokinin is responsible for gall bladder secretions, gastrointestinal motility as well as pancreatic exocrine secretions.
Peptide YY is involved mostly in satiation modulation.
Pancreatic polypeptide function is most apparent in control of gastrointestinal motility and satiation
Amylin controls glucose homeostasis and gastric motility
Glucose-dependent insulinotropic polypeptide possesses an acute influence on food intake through its effects on adipocytes
Glucagon-like peptide-1 has an effect on incretin activity as well as satiation
Glucagon-like peptide-2 is responsible for gastrointestinal motility and growth
Oxyntomodulin plays a role in controlling acid secretion and satiation
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
s secreted by enteroendocrine cells in the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
, pancreas
Pancreas
The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
, and small intestine
Small intestine
The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...
that control various functions of the digestive organs. Later
studies showed that most of the gut peptides, such as secretin
Secretin
Secretin is a hormone that controls the secretions into the duodenum, and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn...
, cholecystokinin
Cholecystokinin
Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
or substance P
Substance P
In the field of neuroscience, substance P is a neuropeptide: an undecapeptide that functions as a neurotransmitter and as a neuromodulator. It belongs to the tachykinin neuropeptide family. Substance P and its closely related neuropeptide neurokinin A are produced from a polyprotein precursor...
, were found to play a role of neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
s and neuromodulators in the central and peripheral nervous systems.
Enteroendocrine cells do not form endocrine glands but are spread throughout the digestive tract. They exert their autocrine and paracrine actions that integrate all of gastrointestinal function.
Types of Gastrointestinal hormones
The gastrointestinal hormones can be divided into three main groups based upon their chemical structureChemical structure
A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...
.
- Gastrin-cholecystokinin familyGastrin familyGastrin and cholecystokinin are structurally and functionally related peptide hormones that function as hormonal regulators of various digestive processes and feeding behaviors....
: gastrinGastrinIn humans, gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the antrum of the stomach, duodenum, and the pancreas...
and cholecystokininCholecystokininCholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein... - Secretin family: secretinSecretinSecretin is a hormone that controls the secretions into the duodenum, and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn...
, glucagonGlucagonGlucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...
, vasoactive intestinal peptideVasoactive intestinal peptideVasoactive intestinal peptide also known as the vasoactive intestinal polypeptide or VIP is a peptide hormone containing 29 amino acid residues that is produced in many tissues of vertebrates including the gut, pancreas and suprachiasmatic nuclei of the hypothalamus in the brain...
and gastric inhibitory peptide - Somatostatin familySomatostatin familySomatostatin inhibits the release of the pituitary growth hormone, somatotropin and inhibits the release of glucagon and insulin from the pancreas of fasted animals. Cortistatin is a cortical neuropeptide with neuronal depressant and sleep-modulating properties....
- Motilin familyMotilin familyMotilin is a gastrointestinal regulatory polypeptide produced by motilin cells in the duodenal epithelium. It is released into the general circulation at about 100-min intervals during the inter-digestive state and is the most important factor in controlling the inter-digestive migrating contractions...
- Substance PSubstance PIn the field of neuroscience, substance P is a neuropeptide: an undecapeptide that functions as a neurotransmitter and as a neuromodulator. It belongs to the tachykinin neuropeptide family. Substance P and its closely related neuropeptide neurokinin A are produced from a polyprotein precursor...
.
Ghrelin is a peptide hormone released from the stomach and is often referred to as the "hunger hormone" since high levels of it are found in individuals that are fasting. Ghrelin antagonistic treatments can be used to treat illnesses such as anorexia and loss of appetites in cancer patients. Ghrelin treatments for obesity are still under intense scrutiny and no conclusive evidence has been reached. This hormone stimulates growth hormone release.
Cholecystokinin is responsible for gall bladder secretions, gastrointestinal motility as well as pancreatic exocrine secretions.
Peptide YY is involved mostly in satiation modulation.
Pancreatic polypeptide function is most apparent in control of gastrointestinal motility and satiation
Amylin controls glucose homeostasis and gastric motility
Glucose-dependent insulinotropic polypeptide possesses an acute influence on food intake through its effects on adipocytes
Glucagon-like peptide-1 has an effect on incretin activity as well as satiation
Glucagon-like peptide-2 is responsible for gastrointestinal motility and growth
Oxyntomodulin plays a role in controlling acid secretion and satiation
See also
- hormoneHormoneA hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
, endocrine systemEndocrine systemIn physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body. The endocrine system is in contrast to the exocrine system, which secretes its chemicals using ducts. It derives from the Greek words "endo"... - digestive system, gastrointestinal tractGastrointestinal tractThe human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
- peptide YYPeptide YYPeptide YY is a short protein released by cells in the ileum and colon in response to feeding. In humans it appears to reduce appetite.It is also known as PYY, Peptide Tyrosine Tyrosine, or Pancreatic Peptide YY3-36....
External links
- Overview of Gastrointestinal Hormones - Colorado State University website