Enterochromaffin-like cell
Encyclopedia
Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell
s found in the gastric glands of the gastric mucosa
beneath the epithelium
, in particular in the vicinity of parietal cell
s. They are also considered a type of enteroendocrine cell
.
ECL cells synthesize and secrete histamine
. These cells are stimulated by the hormones gastrin
and pituitary adenylyl cyclase-activating peptide. G cells are stimulated by vagal stimulation through the neurotransmitter gastrin-releasing peptide; this causes the G cells to secrete gastrin, which in turn stimulates ECL cells to release histamine. Note that this circuit is not activated by acetylcholine, which is of particular importance because the administration of atropine will not block the vagal stimulation of the G cells, as ACh is not the neurotransmitter for these cells.
Gastrin is transferred from a specific type of G cell
in the gastric epithelium to the ECL cells by blood
. Histamine and gastrin act synergistically as the most important stimulators of hydrochloric acid
secretion from parietal cells and stimulators of secretion of pepsinogen from chief cell
s. The most important inhibitor of the ECL cell is somatostatin from oxyntic D cells.
Enterochromaffin-like cells also produce pancreastatin and probably other peptide hormone
s and growth factor
s.
. This is especially important in gastrinoma
(the tumor
s in which there is an excessive secretion of gastrin), as this is one of the factors contributing to Zollinger-Ellison's syndrome. It was once believed that tumors of ECL origin form after a prolonged inhibition of gastric acid secretion, however there is no data to support this conclusion and proton pump inhibitors are not thought to contribute to gastric cancer.
-like staining pattern in histologic sections, which is characterized by silver staining.
Neuroendocrine cell
Neuroendocrine cells are cells that receive neuronal input and, as a consequence of this input, release message molecules to the blood. In this way they bring about an integration between the nervous system and the endocrine system, a process known as neuroendocrine integration...
s found in the gastric glands of the gastric mucosa
Gastric mucosa
The gastric mucosa is the mucous membrane layer of the stomach which contains the glands and the gastric pits. In men it is about 1 mm thick and its surface is smooth, soft, and velvety...
beneath the epithelium
Epithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
, in particular in the vicinity of parietal cell
Parietal cell
Parietal cells, or oxyntic cells, are the stomach epithelium cells that secrete gastric acid and intrinsic factor.Acetylcholine and gastrin . The histamine receptors act by increasing intracellular cAMP, whereas the muscarinic and gastrin receptors increase intracellular Ca2+ levels...
s. They are also considered a type of enteroendocrine cell
Enteroendocrine cells
Enteroendocrine cells are specialized endocrine cells of the gastrointestinal tract. They produce hormones such as serotonin, somatostatin, motilin, cholecystokinin, gastric inhibitory peptide, neurotensin, vasoactive intestinal peptide, and enteroglucagon....
.
Function
Histamine
Histamine is an organic nitrogen compound involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. Histamine triggers the inflammatory response. As part of an immune response to foreign pathogens, histamine is produced by...
. These cells are stimulated by the hormones gastrin
Gastrin
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...
and pituitary adenylyl cyclase-activating peptide. G cells are stimulated by vagal stimulation through the neurotransmitter gastrin-releasing peptide; this causes the G cells to secrete gastrin, which in turn stimulates ECL cells to release histamine. Note that this circuit is not activated by acetylcholine, which is of particular importance because the administration of atropine will not block the vagal stimulation of the G cells, as ACh is not the neurotransmitter for these cells.
Gastrin is transferred from a specific type of G cell
G cell
In anatomy, the G cell is a type of cell in the stomach that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells.G cells are found deep within the gastric glands of the stomach antrum, and occasionally in the pancreas....
in the gastric epithelium to the ECL cells by blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
. Histamine and gastrin act synergistically as the most important stimulators of hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
secretion from parietal cells and stimulators of secretion of pepsinogen from chief cell
Chief cell
In general, a chief cell is a cell which releases a precursor enzyme. There are two types of chief cells which are most commonly referenced:...
s. The most important inhibitor of the ECL cell is somatostatin from oxyntic D cells.
Enterochromaffin-like cells also produce pancreastatin and probably other peptide hormone
Peptide hormone
Peptide hormones are a class of peptides that are secreted into the blood stream and have endocrine functions in living animals.Like other proteins, peptide hormones are synthesized in cells from amino acids according to an mRNA template, which is itself synthesized from a DNA template inside the...
s and growth factor
Growth factor
A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes....
s.
Pathology
A prolonged stimulation of these cells causes their hyperplasiaHyperplasia
Hyperplasia means increase in number of cells/proliferation of cells. It may result in the gross enlargement of an organ and the term is sometimes mixed with benign neoplasia/ benign tumor....
. This is especially important in gastrinoma
Gastrinoma
A gastrinoma is a tumor in the pancreas or duodenum that secretes excess of gastrin leading to ulceration in the duodenum, stomach and the small intestine. There is hypersecretion of the HCl in the duodenum which causes the ulcers...
(the tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
s in which there is an excessive secretion of gastrin), as this is one of the factors contributing to Zollinger-Ellison's syndrome. It was once believed that tumors of ECL origin form after a prolonged inhibition of gastric acid secretion, however there is no data to support this conclusion and proton pump inhibitors are not thought to contribute to gastric cancer.
Name
The name is derived from their location in the enteric system and their chromaffinChromaffin
Taking up and staining strongly with Chromium salts.Chromaffin may refer to:*Chromaffin cells, neuroendocrine cells in the adrenal medulla.*Chromophil cells, hormone producing cells showing chromaffin granules that readily absorb chromium stains....
-like staining pattern in histologic sections, which is characterized by silver staining.
See also
- EnterochromaffinEnterochromaffinEnterochromaffin cells are a type of enteroendocrine cell occurring in the epithelia lining the lumen of the digestive tract and the respiratory tract.-Function:They contain about 90% of the body's store of serotonin ....
- Chromaffin cellChromaffin cellChromaffin cells are neuroendocrine cells found in the medulla of the adrenal gland and in other ganglia of the sympathetic nervous system. They are modified post-synaptic sympathetic neurons that receive sympathetic input...