Local hormone
Encyclopedia
Local hormone
s, by one definition, are biologically active polypeptides that are secreted by nerve
cells and gland
cells and act in a paracrine fashion but also enter the circulation. By another definition, local hormones are any hormones acting in a paracrine, autocrine
, and/or intracrine
manner.
or the secretin
family.
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, by one definition, are biologically active polypeptides that are secreted by nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
cells and gland
Gland
A gland is an organ in an animal's body that synthesizes a substance for release of substances such as hormones or breast milk, often into the bloodstream or into cavities inside the body or its outer surface .- Types :...
cells and act in a paracrine fashion but also enter the circulation. By another definition, local hormones are any hormones acting in a paracrine, autocrine
Autocrine signalling
Autocrine signaling is a form of signalling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on the same cell, leading to changes in the cell...
, and/or intracrine
Intracrine
Intracrine refers to a hormone that acts inside a cell. Steroid hormones act through intracellular receptors and, thus, may be considered to be intracrines. In contrast, peptide or protein hormones, in general, act as endocrines, autocrines, or paracrines by binding to their receptors present on...
manner.
Classification
According to structural and functional similarity, many local hormones fall into either the gastrinGastrin
In 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...
or the 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...
family.
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...
- Glicentin (GLI)
- Vaso-active intestinal polypeptide (VIP)
- Gastric inhibitory polypeptide (GIP)
Others
- MotilinMotilinMotilin is a 22-amino acid polypeptide hormone in the motilin family that, in humans, is encoded by the MLN gene.Motilin is secreted by endocrine M cells that are numerous in crypts of the small intestine, especially in the duodenum and jejunum. Based on amino acid sequence, motilin is unrelated...
- NeurotensinNeurotensinNeurotensin is a 13 amino acid neuropeptide that is implicated in the regulation of luteinizing hormone and prolactin release and has significant interaction with the dopaminergic system...
- 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...
- SomatostatinSomatostatinSomatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...
- BombesinBombesinBombesin is a 14-amino acid peptide originally isolated from the skin of a frog. It has two known homologs in mammals called neuromedin B and gastrin-releasing peptide. It stimulates gastrin release from G cells. It activates three different G-protein-coupled receptors known as BBR1, -2, and -3. It...
- SerotoninSerotoninSerotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...