Enterochromaffin cell

Enterochromaffin Cell

Chemical structure of serotonin, a key neurotransmitter produced by enterochromaffin cells.

Enterochromaffin cells are a type of neuroendocrine cell found in the epithelium of the gastrointestinal tract. These cells are primarily responsible for the synthesis and secretion of serotonin, a crucial neurotransmitter that plays a significant role in regulating intestinal motility and secretion.

Structure

Enterochromaffin cells are dispersed throughout the mucosa of the stomach, small intestine, and colon. They are characterized by their ability to take up and decarboxylate amino acids, a process that is essential for the production of serotonin. These cells contain numerous secretory granules that store serotonin until it is released in response to various stimuli.

Function

The primary function of enterochromaffin cells is the production and release of serotonin. Serotonin acts on the enteric nervous system to regulate peristalsis and gastrointestinal secretion. It also plays a role in nausea and vomiting by acting on the central nervous system.

Serotonin Synthesis

Serotonin is synthesized from the amino acid tryptophan through a series of enzymatic reactions. The first step involves the hydroxylation of tryptophan to form 5-hydroxytryptophan, which is then decarboxylated to produce serotonin. This process occurs within the enterochromaffin cells and is crucial for maintaining normal gastrointestinal function.

Clinical Significance

Dysfunction of enterochromaffin cells can lead to various gastrointestinal disorders. For example, an overproduction of serotonin can result in carcinoid syndrome, characterized by flushing, diarrhea, and bronchospasm. Conversely, a deficiency in serotonin production can contribute to conditions such as irritable bowel syndrome (IBS).

Related Pages

• Neuroendocrine cell
• Serotonin
• Gastrointestinal tract
• Peristalsis
• Carcinoid syndrome